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Ksarul
May 9th, 2009, 08:19 PM
Anyone else on the forum have a Cortex? I just got one and I don't have a lot of information on it yet.

For those wondering why it is in the TI section, it uses a TMS9995 microprocessor and all of the ancillary support chips are TI as well, even the disk controller (which I am still trying to acquire, as the disk subsystem components were not installed on the machine I got).

nige the hippy
May 10th, 2009, 05:58 AM
I do, mine's missing the memory map chip, but I'm still trying to find out if that was an option, and also hoping to need some other silicon to put together a worthwhile order for spares. It has however got the disk drive bits in place.
I lusted after one of these after seeing the articles published in ETI (Electronics Today (International!)) all the schematics (and construction details - it was a kit) are available as PDFs online (I can email you them if you send me a PM). from rusty memory I'm not sure that it wasn't a "Transam" design, so it may share some design heritage with the equally obscure "Wren Executive" also Alasdair McRae-Birch (who still exists) may have had someting to do with it. but I don't know for sure.

Ksarul
May 10th, 2009, 08:10 PM
I have all of the documentation that was on Oldcomputers--along with a couple of additional pages that came with mine that weren't in the Oldcomputers archive. As of this morning, I also have the 220 page manual for CORTEX BASIC. A friend of mine in Germany sent it to me when I asked about the machines yesterday on one of the Yahoo groups. He also has one, though his needs a new power supply. Like mine, it does not have the disk subsystem installed. Reading the manuals, I didn't see a way to actually FORMAT or SAVE to the disks listed. Everything was based on booting a program from the disk (which should be in IBM3270 Format?) .

I understand your long-term lusting after one of these--I've been trying to get my hands on one since around 1988, though the hunt only became continuous in the last ten years or so. . .do you need the BASIC manual?

chuckcmagee
May 10th, 2009, 08:36 PM
I have a frontal cortex, does that count? :cool::rolleyes:

nige the hippy
May 11th, 2009, 03:40 AM
I understand your long-term lusting after one of these--I've been trying to get my hands on one since around 1988, though the hunt only became continuous in the last ten years or so. . .do you need the BASIC manual?

I'd love the basic manual. pdf, I presume (!) if it isn't, it's probably as cheap to get it scanned, as it is to get it photocopied (and a lot cheaper to post) it's probably worth sending a copy to "old computers.com" .| "bitsavers" for archiving too. I was going to peek the rom for keywords had it not existed.

Funny about the disk system possibly not being fully supported, looking at the original article it's "glossed over" a bit I wonder if the code was never properly written - or if they ran out of rom! In 1982 disks were still a minority interest.

The chap in Germany should be able to rebuild the power supply fairly easily. Even if the transformer's gone away he could replace it with a standard 12-0-12 toroidal one, and wind on the winding for the 5V. It'll probably only be about 20 turns of thickish (about 1mm^2) wire
I suppose if the supply is missing completely, a little pc one would do the job with the power control wire shorted to ground to turn it on.

It was way in advance of anything available to the mere mortal at the time!

Ksarul
May 13th, 2009, 06:37 PM
The manual version I have is in the form of 220 pages of GIF images. I've been converting them to an editable text document, but the going is slow because the copy I have is relatively bad, so the OCR software needs a lot of help to turn it into something useful. I've finished the first 10% or so of the manual in the last week or so. It is still a lot faster than typing it in manually. I will send you a soft copy as soon as I'm finished with the conversion. If you need it sooner, I can send you the raw GIF images.

I'll let my friend in on your idea with the power supply. Many thanks!

nige the hippy
May 14th, 2009, 03:08 AM
sounds like a labour of love!
Have you considered running a spell checker through it first? (Or is that the way you're doing it anyway) Usually quicker than manually reading & correcting.
I wonder how many Cortices there are still out there? you've probably got half a week's work per existent machine.
We owe you!

Ksarul
May 15th, 2009, 12:00 PM
Well, I know of three confirmed machines: mine, in the USA, my friend's in Germany, and yours. I also know of one more that was sold on eBay a few months ago. That is more than enough for me to ensure manual preservation. . .and a spell checker doesn't help rebuild mangled tables, unfortunately. I actually just did the pages as raw text dumps and then rebuilt the formatting on my own as a project to keep me busy during random moments of downtime. That way, I finish 2-5 pages at a whack and don't spend enough time on it at any one time to get bored with the task.

I've also been looking at the memory map chip issue--it should only need the memory mapper if you are trying to build the 256K memory option. The 74LS610 is getting really difficult to find anymore (there is a seller on eBay wanting $30 each for them), but there is also a guy on one of the 6502 forums who designed a plug-in board with relatively common LSI chips to substitute for one (probably would cost more than the $30 chip, but it would be fun). It should be relatively easy to write a VHDL program that works like one as well--then it could be done with a single-chip replacement. I'm just starting to learn VHDL though, so it may be quite a while before I can look at something like that. It would give me VHDL practice since I eventually plan to reverse-engineer the gate arrays for a 99/8 though.

I am still scouring my parts sources for better prices on them though, since that is the primary option. Most of them only had the 74LS612 though, which is similar but with fewer registers.

nige the hippy
May 15th, 2009, 03:45 PM
The schematics show the '612 - ebay (uk) item shown below


Item number: 180273705894

but I'll check

Reason I'm doubting it's need, is 4 jumpers (4 address lines?????) near the chip, which I couldn't find on the diagrams, and that mine's missing. I could do with knowing the truth before powering on. I suppose I could lift the board & start "knife & forking" * it through, but I have other priorities at the moment.


* meter & patience (rather like removing fish-bones)

Ksarul
May 17th, 2009, 09:11 AM
I went back to the schematics again--the block diagram lists a 74LS610, but the parts list and the rest of the schematics list a 74LS612. I ordered a bunch of the 612s from a supply house I regularly deal with (Unicorn) just in case. I'll look at the board on mine to see if either chip is installed later today.

Not sure why they would have been using four jumpers for address lines there, unless they were using 16K memory blocks in a 256K range. That does plot out at least, if two of those jumpers also feed back into the original memory chip array address lines. The other possibility would be that each line activates a single, 64K block--again, the other end of the line will give clues to see if that is the case. If I fish-bone mine to see where they go, I'll post the results here. . .

tms9995
June 12th, 2009, 11:26 PM
Hi Guys,

Well, I have to say this is the first time I've ever joined/replied to any online forum, but I felt the need to contribute. Every once in a while I type "Powertran Cortex" into Google to see what shows up and this time I found this thread!

I own two of these great machines, both fitted with the disk interface hardware. I have one here in the States, and one at my parent's house back in the UK. I also built a third one from a kit (the Cortex II - same internals but different case to look like a BBC Micro) for my best friend but that one is no more (but he's still my best friend!).

I know a lot about their workings etc. Your interest seems mostly in the disk interface and its use. It uses the TMS9909 Disk Controller and the TMS9911 DMA. The ROM (Cortex Basic) had a command called BOOT. This reads the first sector on the disk and executes it, which subsequently loads the remainder of the Disk Operating System from the disk.

There was a company called Marinchip Systems based out in California. They had various TMS9900 systems and a couple of Operating Systems. One was called MDEX (Marinchip Disk EXecutive) and NOS (Network Operating System). One of the key people there was John Walker and he initially created the foundation of AutoCAD on this platform! Micro Processor Engineering (MPE (or uPE)) migrated MDEX to the Cortex platform and that was its first 'DOS'.

The big problem was that MDEX was a completely different OS/environment to Cortex Basic. It was really a text-based/VT100 based OS, so none of the graphics were available. You couldn't run anything you had developed under Cortex Basic and the commands were very simple - kinda CPM ish. It pretty much made the Cortex HW emulate a single VT100 and that was it. It had a bunch of apps you could buy (I'm talking loads of money and I was 14!) such as QBASIC (compiler) and SPL (Systems Programming Language kinda like C) and some others.

A couple of years later, a guy called Neil Quarmby, who worked for TI in the UK (and I believe created the Cortex Basic release of TI Power Basic) released CDOS (Cortex Disk Operating System) and this was the cats ass! It was the disk extension to Cortex Basic. Turn the machine on, type BOOT and you were away! Everything as it was + a disk filing system - awesome! You chucked out the cassette player that night!

I have MDEX and CDOS on disks and they work. I have also written a Cortex emulator under Borland C++ Builder 5 (yeah I know that's old too) and have some disk images converted to PC files so that you can BOOT them. I also have just about every MDEX + APP manual. My biggest problem is that I'm extremely busy in my day to day stuff and I was somewhat reluctant to write this but since you have a shared passion, I couldn't resist. I would like to help revive this machine but need patience.

Hope this is useful,

Dave.

nige the hippy
June 13th, 2009, 07:52 AM
Holy cow, I didn't know about Autocad! That makes it a historically important machine (well a bit!) instead of just the object of my droolings in ETI (Electronics Today International) magazine. Now that would be a nice bit of software to own.

And HELLO! and thanks for posting.

My day job is 2 toddlers and a half-finished house, so I'm a bit slow. I just can't help but say "yes" if something good comes my way. And my excuse for owning the number of machines I do, and not having enough time to work on them is that in a couple of years I will have enough time, but probably won't be able to afford the raw materials.

tms9995
June 13th, 2009, 08:31 AM
Thanks for the welcome.

Reading back on my first post (ever!) I guess that sounded a bit rude about 'needing patience'. I didn't mean it to come off like that - I was just indicating it might take a little time for me to reply to any requests, so appologies if I got off to a bad start!

With regards to the memory-mapper. The correct part is 74LS612, but the 74LS610 can be used with pull-up resistors. It is not needed for normal use. The idea was using the '*' command (eg *PACMAN), Cortex Basic would page in 'external memory' (I guess it was conceived to be a ROM pack) and search for a header called PACMAN, load and run the chosen program. What most of us did was add 256K of RAM instead and write progs that we loaded into it upon booting CDOS. Although I never quite finished it, I created HDOS (Hard Disk OS) based on a SCSI interface that was loaded into the expanded memory. All good fun!

I got and idea this machine was released to ETI after TI abandoned the TI99/8. I know there are some differences but this machine is all TI so why they would design a complete computer for a hobby magazine is a little strange. Anyone have any info on this?

Not sure on the legalities of posting copies of CDOS, MDEX, ROMS etc. Obviously TI, John Walker and Mike Riddle (he wrote SPL for MDEX and was involved with the AutoCAD development) are still around. My emulator more or less works (no graphics modes yet but they never really interested me).

Anyway, here to help.

nige the hippy
June 13th, 2009, 09:59 AM
I thought my machine a little strange in that it seemed complete except for the '612, but there were 4 jumpers on the pcb next to the '612 that seemed like options. It made sense if they were the 4 upper address lines hard-mapped straight through. I haven't had chance to meter them out, and I'm trying to resist doing projects 'till the loft space is usable. (Then.......)

Software wise...
If you actually know the people involved in the software, it would only be polite to ask, and I'm not sure how long copyright lasts, but I'd be inclined to at least send the binaries/images of the software you have to Al Kossow at Bitsavers for archiving, It's pretty secure as it's mirrored on quite a few servers. You may go under a bus next week( :( ), and maybe you have the only copies left.

Strange you weren't into the graphics, I was under the impression that it was one of the highlights of the machine.

Post didn't sound the slightest bit rude, there are some who post here fairly regularly who are on the autistic-spectrum and they usually get excused!

tms9995
June 13th, 2009, 03:07 PM
I'm pretty sure the jumpers, as you say, just pass through the upper 4 bits of the address bus in the absence of the mapper chip. The CPU has a couple of its External Intructions (CKON and CKOF) decoded to turn the mapper on/off respectively. When the chip is fitted and in the un-mapped mode (normal), it simply passes through these bits. When on, it adds an additional 4 bits to provide a possible 256 4K pages (only 16 can be paged in at any one time) thus providing for up to 1MB of extended memory.

As for the graphics, well I guess you have to be somewhat 'artsy'! The TMS9928/29 VDP was pretty cool, but to do any fast hi-res stuff was quite difficult as the video ram was not accessible directly so you had to transfer it to CPU ram, manipulate it and then send it back via a couple of registers.

The 40x24 text mode was a little limiting, so a bunch of us upgraded to the backwards-compatible MSX Video Chip (the V9938). This was available on a PCB from Maplin for some kit they had at the time. Someone came up with a package that patched Cortex Basic so that you had 80x26 text and some additional high res graphics modes (it had 128K of video ram instead of the original 16K).

I was attracted to this machine for a number of reasons. Firstly, when you powered it up it copies the ROM image into RAM. This makes it so easy to patch/enhance the operating system without having to burn some more Eproms! Secondly, because it was such low volume, there was a small community that, between us, pretty much had to come up with our own hardware and software which forced a learning curve that was really absent on any other platform at the time (and even now). It had a built-in assembler/disassembler and debug monitor where you could set breakpoints, inspect registers and so on. Not to mention it was 16 bits with hardware multiply & divide!

Basically, this machine allowed me to develop skills in assembly language programming and digital design that I have used in my professional life since. I work in flight simulation and, like the aircraft, these machines are around for a long time (a new one today would cost about $12,000,000). Hence it's not unusual to be doing a modification in 32 bit assembler on a super-mini that's circa 1978!

I don't actually know the people involved, I just know their names from looking at the MDEX software sources and documentation. From Googling, John Walker is the co-founder of Autodesk (!!!) and Mike Riddle is also still in the CAD business in Pheonix (bitter split between him and John in the mid-80's). You can hear him talking about the early days using the TMS9900 based system and his SPL language at
http://www.digibarn.com/stories/mike-riddle/MP3_96_mike-riddle1.mp3

There is no way of knowing that Neil Quarmby wrote CDOS. I just happen to remember sending him the cheque for it and getting his TI business card back with the order. He can be found with a quick Google too!

I suppose in light of the fact that I very well could have the only remaining copies of this stuff it would be prudent to back it up to a website/repository somewhere and just make it clear that is why it's there! As long as it's clear that for someone else to use it they should seek the permission of the respective copyright owners, it should be OK? It has no commercial value whatsoever and would be very educational for people to be able to experience what was available back then.

tms9995
June 13th, 2009, 03:13 PM
How did that smily get in my post? It was supposed to be V9938. Like I said, I'm new...

Ole Juul
June 13th, 2009, 03:26 PM
@tms9995: I was just looking around the net to see what one of those looked like. The Old-computers.com (http://www.old-computers.com/museum/computer.asp?st=1&c=171) site has a little information but state that "We need more info about this computer ! If you designed, used, or have more info about this system, please send us pictures or anything you might find useful." It sounds like you have something to add. :)

tms9995
June 13th, 2009, 03:56 PM
Thanks. I went over there and posted something in the 'comments' section. Hopefully that could stir something up? Hard to know what to send them - maybe the emulator...

Ksarul
June 14th, 2009, 06:21 AM
Wow! Lots of nice additional bits of information there TMS9995! I just got a few of the TMS9909 and TMS9911 chips in from about the only place on Earth that seems to have stocks of them--Hong Kong/China. I got half a dozen of each of them just in case. . .but in all your posts I see two very important things (three, counting the fact that you have TWO Cortices): you have a lot of documentation that likely exists nowhere else, and you have a lot of the software to go with it. Please put those things up online somewhere. :)

I can also answer your TI-99/8 question. I am probably the only person in the world who has both a Cortex and a 99/8. I spent a several of years (and about 2K) tracking down all of the documentation for the 99/8 and then promptly photocopied it and put it up on the WHTech FTP site. I was told for years that most of the documentation I found no longer existed. I talked to the original engineers and dug up all but one item--the internal logic diagrams for the AMIGO chip. I have the complete operational description for it though, along with the pin-out, so I may just try and reconstruct it in VHDL one of these days. The Cortex and the 99/8 are VERY different. To see just how much so, you can look at all of the data I posted on WHTech:

ftp://whtech.com/datasheets%20&%20manuals/99-8%20Computer/

As a side note, work on the 99/8 began at about the same time ETI would have been preparing their first article for inclusion in the magazine. They were still testing two different versions of their motherboards in August/September 1983 to see which one was operationally better (two different expansion bus connectors/pinouts and some other component differences, most minor). The complete source code for the 99/8 system is on WHTech as well. I helped a friend (Dee Turner) rescue that from a dead hard disk about 20 years ago. It started my quest for 99/8 information.

Thank you for posting--I now know of a total of six Cortices that survive, though I have no contact with the owner of one of them. I also have some other questions: do you know which issues of ETI had Cortex articles in them after the Nov/Dec 1982 and Jan 1983 issues? I saw evidence that there were occasional additional articles in ETI up through at least 1987. I have the issues from Nov 1982 through Sep 1984 on their way to me via slow boat as of yesterday, so I will be able to make scans of some of that documentation from an original shortly. Do you have any means (and/or time) to bulk scan the documentation you have to easily put it up online?

Nige, I'm almost finished converting the Cortex BASIC manual JPGs I received from Germany to a fully-editable file (I'm starting the 22 pages of the appendices now, and then it will be done). I'll create a directory on WHTech for the Cortex and put it up there as both a PDF and a Word document, probably in about a week. Your wait is almost over, and much shorter than originally expected :) A work trip helped a lot, as I got to work in my hotel room uninterrupted during the evenings. . .

tms9995
June 14th, 2009, 01:04 PM
Congrats on obtaining the FDC & DMA chips. They were both expensive and hard to come by in the 80's! The disk interface was designed to accommodate just about every drive and density combination available at the time and could be a little bothersome to get 'just right'. Although it catered for 8" drives, we all had some combination of 5.25 in 40T/80T Single/Double Sided/Density. When you finally achieved ownership of a pair of 80T/DS/DD drives (640K formatted capacity each) you felt like you'd won the lottery! Single Density was pretty reliable but the PLL for DD was a little sensitive to temperature etc. and could use a little tweaking from time to time. However, mine still works the last time I tried it!

We have a scanner with a sheet-feeder on it and I quickly tried a 36 page manual this morning and it scanned to a pdf in about 5 mins so looks like the A4/letter sized stuff should be easy.

I don't like reinventing the wheel, so is there a free site I can put this stuff on? I had a look at the whtech ftp site and there is loads of stuff on there but not sure how to add to it. If someone can point me to an account that's secure/safe/free, I'll upload some stuff.

As for the ETI articles, I think some of that stuff in still in the UK. I have a copy of something called Electronics Digest and it was basically an ETI Special that has the original 3 part series for the Cortex and some other select projects. I also have most of the User Group News Letters that contain loads of mods, tips, tricks etc. I'll scan the lot given enough time. The big one will be the firmware. I was lucky enough to be given the entire source code for the Eproms in a TI ring binder! It must be 4" thick of individual pages...

linuxlove
June 14th, 2009, 02:42 PM
If you want, I can host the manual on my vintage computing archive.

nige the hippy
June 15th, 2009, 12:34 PM
By all means pop a copy on the above site, but Bitsavers is THE place. The more places the merrier, and there are sick looneys out there who like hacking/wrecking archives.
It's quite a bit of work doing the scanning etc, I was trying to get a sheet feeding scanner sorted, but they seem to go at a premium on ebay. I have heaved a sigh of relief that the 3-foot-thick pile of dec & cdc manuals I have are already in the public domain.
Thanks to the comments so far I feel confident enough to check out the psu and then hit the on switch without fitting the memory mapper. however as usual, my weekend evaporated!

tms9995
June 15th, 2009, 11:06 PM
Both sites sound good. Bitsavers seems more appropriate, but looking at their general requirements, it seems they cater for true mini/mainframe computers rather than a home micro with a 'mini' cpu. Thoughts before I jump through the hoops of bothering them?

The whtech site Ksarul talks about looks good too since there is a lot of TI stuff on there, but still waiting to see if it's possible to use that site. Ksarul?

In any case, first I have to build up my collection of pdf's and binaries, but need to be sure I have a good place to share it before I put the effort in!

Nige: With regards to the sheet feeder/scanner, all we have is a Brother MFC-490CW scanner/fax/printer and it cost about $99, which isn't a lot...

Ksarul
June 16th, 2009, 02:02 PM
I've got an upload account on WHTech, so if you get the data to me, I can put it up there for you. Alternatively, you can ask the owner for one of your own--he usually grants them immediately to people he's seen in the community before, though he might ask you a few more questions since you're new to him.

tms9995
June 16th, 2009, 03:13 PM
Thanks Ksarul, I'll just send you the stuff. I brand new to this so wouldn't want to insult someone for an account when they don't know me from Adam! Once I get some scans etc., I'll let you know and we'll take it from there. I'll upload to others when I get it all together.

Ksarul
June 16th, 2009, 04:25 PM
Here's a link to the CORTEX POWER BASIC Manual. I uploaded it today and created a Cortex folder for future submissions.

ftp://ftp.whtech.com/Powertran%20Cortex/

Many thanks for taking the time to scan the documentation you have TMS9995!

tms9995
June 16th, 2009, 04:47 PM
Wow - awesome job with the Cortex Power Basic manual. I haven't looked at that for years (mine's still in the UK) and certainly brings back some memories! I will make an effort to get the emulator tidied up and posted (not that much to do) as you can apply this manual right away!

Just found out my cheap scanner slows down considerably after you shove more that about 25 pages through it. I guess it has to cool down...

Ksarul
June 16th, 2009, 06:49 PM
Many thanks--I ran it through an OCR program and then edited it to make sure no errors crept into the resulting document. . .

nige the hippy
June 17th, 2009, 06:42 AM
:D

Many many thanks Ksarul, the dialect looks a little strange. I probably would run into a few unfathomable walls in the first few lines without it.

Tony Rowell
June 27th, 2009, 04:31 AM
Hi everyone, I was a pleasantly surprise to find this forum with such recent activity about the Cortex.

I was one of the developers of the Cortex along with Jim Gill, Neil Quarmby, Colin Hinson and Ian White so I can fill you in on a lot of the history behind the Cortex and info on both the hardware and the software.

I still have 2 of the machines up in the loft somewhere although they haven't been powered up for a few years.

nige the hippy
June 27th, 2009, 05:43 AM
wow! celebrity! I' just off out now, but I'll be adding my questions to the list!

Ksarul
June 27th, 2009, 09:28 AM
Do you possibly have a datasheet/the compete function pin-out for the 74LS2001 used on the E-Bus interface? Information on that one seems to be completely lacking on the net or anywhere else. I haven't even been able to find a source for the E-Bus System Design Handbook (MP402) from TI. One source in Poland apparently still has some of the chips, but I haven't been able to confirm that yet. If they do have any, they are likely the last source on Earth with any quantities of them. . .

And thank you for dropping in here--information on the Cortex is always useful, and any data you can provide on its background is invaluable! Right now, the sum of what I have are the articles from ETI that appeared in NOV 1982, DEC 1982, JAN 1983, FEB 1983, JUN 1984, AUG 1984, and SEP 1985. I also have the construction manual from Powertran (for the minimal setup without any options) and the POWER BASIC manual (which I converted to an editable PDF from a series of GIF images). Any additional documentation (with or without the associated software) would be greatly appreciated.

I'm in the process of trying to build the options into my Cortex. I have acquired a number of the TMS9909 and TMS9911 ICs to work on the disk system, but the E-Bus has been a hard nut to crack into. With enough data, I may have to try and reverse-engineer it in VHDL and roll my own. . .

I do have the E-Bus patent description with the internal logic and timing, but not where the signaling should go (some of it will become obvious from tracing signals on the Cortex, but not all--as that is my next planned attack vector).

Ksarul
June 27th, 2009, 09:32 AM
TMS9995, one of your earlier comments reminded me of something I haven't thought of in ages. Marinchip Systems also built a TMS9900 board for the S-100 bus. I was looking for one of those for a long time but never did encounter anyone who'd ever heard of it or them. Thanks for the reminder. . .one more vintage 9900-family system for me to track down. :)

chuckcmagee
June 27th, 2009, 10:10 AM
How did that smily get in my post? It was supposed to be V9938. Like I said, I'm new...

If you happen to type an 8 immediately followed by a ) it shows up as a 8)

I just add an extra stupid space between the 8 and the )

like V9938 )

tms9995
June 27th, 2009, 02:07 PM
Hi everyone, I was a pleasantly surprise to find this forum with such recent activity about the Cortex.

I was one of the developers of the Cortex along with Jim Gill, Neil Quarmby, Colin Hinson and Ian White so I can fill you in on a lot of the history behind the Cortex and info on both the hardware and the software.

I still have 2 of the machines up in the loft somewhere although they haven't been powered up for a few years.


Hi Tony, thanks for stopping by! I would love to hear what you know about this machine. Most of my knowledge is from the User Group that was around at the time, plus the usual 'reverse engineering' that goes on whilst you got your head burried in the datasheets! It would certainly be refreshing to get some insight from someone who was on the inside.

tms9995
June 27th, 2009, 02:09 PM
If you happen to type an 8 immediately followed by a ) it shows up as a 8)

I just add an extra stupid space between the 8 and the )

like V9938 )

Thanks for the tip! I'll figure it all out eventually...

Tony Rowell
June 27th, 2009, 02:17 PM
I don't remember anything about the LS2001 off the top of my head but I'll have a look around to see what I can find, it is quite possible that it never actually existed.
I do however have a copy of the e-bus system design book (MP402) in my hand at the moment, it's about 1cm thick so a lot of copying.

tms9995
June 27th, 2009, 02:22 PM
Do you possibly have a datasheet/the compete function pin-out for the 74LS2001 used on the E-Bus interface? Information on that one seems to be completely lacking on the net or anywhere else. I haven't even been able to find a source for the E-Bus System Design Handbook (MP402) from TI. One source in Poland apparently still has some of the chips, but I haven't been able to confirm that yet. If they do have any, they are likely the last source on Earth with any quantities of them. . .

And thank you for dropping in here--information on the Cortex is always useful, and any data you can provide on its background is invaluable! Right now, the sum of what I have are the articles from ETI that appeared in NOV 1982, DEC 1982, JAN 1983, FEB 1983, JUN 1984, AUG 1984, and SEP 1985. I also have the construction manual from Powertran (for the minimal setup without any options) and the POWER BASIC manual (which I converted to an editable PDF from a series of GIF images). Any additional documentation (with or without the associated software) would be greatly appreciated.

I'm in the process of trying to build the options into my Cortex. I have acquired a number of the TMS9909 and TMS9911 ICs to work on the disk system, but the E-Bus has been a hard nut to crack into. With enough data, I may have to try and reverse-engineer it in VHDL and roll my own. . .

I do have the E-Bus patent description with the internal logic and timing, but not where the signaling should go (some of it will become obvious from tracing signals on the Cortex, but not all--as that is my next planned attack vector).


We'll see what Tony has to say, but it is my understanding that the 74LS2001 was essentially just a made up name for a gate array to control the E-Bus arbitration and timing. I have never known of one to exist. I guess the intent was to develop all these intelligent multi-processor peripherals for the Cortex, so a sophisticated expansion bus was added to the design but it was never really utilised in that way. So, there was a simple circuit built onto a header board that plugged into the infamous U89 socket (I have the details) that basically allowed the Cortex to drive the E-Bus as a simple expansion bus, without permanently locking up waiting for a Bus Grant signal.

tms9995
June 27th, 2009, 02:39 PM
TMS9995, one of your earlier comments reminded me of something I haven't thought of in ages. Marinchip Systems also built a TMS9900 board for the S-100 bus. I was looking for one of those for a long time but never did encounter anyone who'd ever heard of it or them. Thanks for the reminder. . .one more vintage 9900-family system for me to track down. :)

Yeah, that was the system MDEX and the first version of AutoCAD was designed on/for. In one of my first comments, I didn't mean to imply the Cortex was used for this purpose.

I have been scanning for over a week now and have been encountering some quality issues etc. using the cheap scanner. However, my better half has a big networked Ricoh copier/scanner at her office :D. I have, er, given it a 'trial run' late at night and it does a very good job scanning to my laptop, so I am re-doing everything which will take some time, but will be worth it in the end.

So far I have done the entire ROM Source Listing (582 pages!), MDEX Assembler, MDEX System Generation, MDEX Debug and CDOS 1.1.

Also, the emulator is about ready for deployment. I'm just finishing up emulating the 9909 Format command. I don't pretend to be an award winning Windows programmer, so please excuse it's presentation. It works very well, but it's kind of light on the bells and whistles...

Tony Rowell
June 27th, 2009, 02:46 PM
Ebus cards definitely existed, the bus was one that TI used for a range of eurocard sized boards and the cortex just used that bus as a means of expansion. All of the cards I remember had discrete logic for the bus arbitration & control, I think the LS2001 was a number allocated for a gate array that never came to fruition.

tms9995
June 27th, 2009, 02:56 PM
So Tony, can you give us a little history about the Cortex as a project? It's a pretty serious piece of kit for a big company to put all that effort into just for a magazine project. It surely had to be an abandoned commercial home/business computer product? We know about the TI99/8 that was dropped at the last minute, was this something similar? Do tell ;)

Tony Rowell
June 27th, 2009, 03:10 PM
The cortex came about as an extension of a group of us at TI trying to build ourselves a home computer out of "scrap", remember that at the time a home computer was somewhere between non-existant and insanely expensive. We started of by taking faulty viewdata boards (sort of teletext over a dial-up modem) based on the TMS9980. When the TMS9995 came out we started looking at building something around that. At that time TI had a minicomputer division (990/12 etc) and a home computer division (99/4A) with lots of internal politics to ensure that the home computer didn't tread on the minicomputer dept toes so to speak, we however worked for the semiconductor division an just wanted to build something and management just wanted to sell chips. The semiconductor division building a home computer was a big no-no, it would have been stomped on by both the home computer division & the minicomputer division so we had unofficial encouragement to go ahead with the design and the way to "get it out" was ETI (as long as there was no direct connection to TI), Powertran simply made the kits & sold it.

Jim Gill and myself did the BASIC (based on one from TI but mostly rewritten), Colin Hinson did the debug monitor, Neil Quarmby did the schematics and floppy boot code and Ian White did hardware prototyping and "resourcing".

Originally the computer was named "Synapse" and the first prototype photos showed that name but it was renamed at the last moment because of a conflict with another product with that name.

tms9995
June 27th, 2009, 03:32 PM
Some fantastic information there Tony - thanks! It must have been very cool to have all the resources available in-house and just be let go to do your own thing. Talk about kids in a candy store!

Tony Rowell
June 27th, 2009, 03:37 PM
This is the schematic of the ebus arbiter from the design manual, probably the LS2001 was intended to have this inside. Should be doable with a simple PAL these days.

For those people looking at the memory mapper chip I seem to remember that we could use eithe a LS610 or a LS612 and that one of those was used in old XT class PCs so if you can track down an old old PC motherboard you might be able to reclaim the chip. The memory mapper remapped the top 4 address lines from the processor, thats why there are 4 links to bypass the mapper if it isn't fitted.

Tony Rowell
June 27th, 2009, 03:43 PM
resources were available but not officially, lots of favours and being resourceful with all the work being done out of hours but it was a lot of fun too.

tms9995
June 27th, 2009, 03:57 PM
So once it was out the door to ETI/Powertran was that it or did you remain involved with support/further development? I only know Neil was involved later on because he was selling CDOS for about 50 pounds per copy in 1985. Now that makes sense, since you said he was the one who did the floppy code! When I was scanning the ROM listing, I noticed that the comments for the floppy boot are in lower-case, whereas the rest of it is in upper-case. I guess he had his own style...

Tony Rowell
June 27th, 2009, 04:08 PM
I wasn't with TI shortly after the magazine article came out although I did go back to work for them years later. Part of the deal with the cortex was that we got one of the kits each as "payment" and it my macine and Jim Gill's that I have in my loft. None of the group are still with TI but with the exception of Ian White I know where they still are so fortunately still accessible for anything I've forgotten.

tms9995
June 27th, 2009, 04:20 PM
I guess it's only fair to ask, but as I plan on making my Cortex Emulator available to anyone on here that may be interested (like 3 people!), I will obviously be posting the ROM image which I guess is your work! Do you have any objections? Also, I would like to put up CDOS. Do you think Neil would mind? (Perhaps you could ask him). I would feel better knowing. Thanks.

Tony Rowell
June 27th, 2009, 04:26 PM
I don't think anyone would care, if push came to shove then TI would probably claim that they owned everything (naturally) but this is all so far in the past and of no commercial interest to anyone.

tms9995
June 27th, 2009, 04:37 PM
Thanks. Like I said, I feel better for asking! If it was my stuff, I'd be honoured 26 years later!

I don't suppose you have the ROM source on disk anywhere? As I've said, I have the SDSMAC listing output, but would love to be able to rebuild the ROM from source files.

Tony Rowell
June 27th, 2009, 04:54 PM
Maybe processing the listing will give you a machine readable copy of the source code. As a matter of interest how did you come by the listing?

tms9995
June 27th, 2009, 05:07 PM
Yeah I guess the next step would be to try and put it through OCR to try and extract the text.

In 1994/5 I had built a SCSI interface for the Cortex and had more or less finished what I called HDOS. For the life of me I can't remember what for but I needed some info so I went through all the User Group letters I had (which was extinct by about 6 years plus!) and I tried contacting some of the people involved. I ended up meeting with one of the guys who had run the Group and he said if I gave him the hard drive/SCSI design and driver code, I could have everything he still had. One of those things was the listing! I don't know how the User Group got it though. I also got some extra manuals for the MDEX O/S plus a couple of other compilers & tools for MDEX. There was a lot of passing stuff along as each of the bigger companies involved no longer wanted to support the machine any longer. I always hung on to everything I got as I wanted to get back into it 'one day'...

Ksarul
June 30th, 2009, 07:52 PM
I do have a bunch of the 74LS612 Memory Mappers, so that chip isn't a problem either--the problem was with the pinout of the 74LS2001, since that is the one chip I don't have sufficient info on. Many thanks for the extract of the bus arbiter logic.

Seeing all of the information that is actually out there for these has me in a major state of anticipation to read all of it! I plan to put direct scans of all of the ETI articles I have original copies of into the Cortex folder on WHTech this weekend, including a single high res scan of the component side of the board instead of in halves like the other copies I've seen.

One interesting question, the component mask numbering on mine bears absolutely no resemblance to any version described so far--almost everything is different. . .but the component positioning is the same. Any idea how that one came to be, and are there schematics that reflect this other number scheme (note it isn't the minor changes noted in either the ETI articles or the Powertran construction manual that reprinted them with some corrections)?

Once again, many thanks!

Tony Rowell
July 2nd, 2009, 01:08 AM
tms9995 - was the info in my PM of use?

tms9995
July 2nd, 2009, 01:19 PM
I didn't know I had a PM. I'll check it out - thanks

tms9995
July 2nd, 2009, 01:28 PM
I do have a bunch of the 74LS612 Memory Mappers, so that chip isn't a problem either--the problem was with the pinout of the 74LS2001, since that is the one chip I don't have sufficient info on. Many thanks for the extract of the bus arbiter logic.

Seeing all of the information that is actually out there for these has me in a major state of anticipation to read all of it! I plan to put direct scans of all of the ETI articles I have original copies of into the Cortex folder on WHTech this weekend, including a single high res scan of the component side of the board instead of in halves like the other copies I've seen.

One interesting question, the component mask numbering on mine bears absolutely no resemblance to any version described so far--almost everything is different. . .but the component positioning is the same. Any idea how that one came to be, and are there schematics that reflect this other number scheme (note it isn't the minor changes noted in either the ETI articles or the Powertran construction manual that reprinted them with some corrections)?

Once again, many thanks!


If you get the 31 page download from old-computers.com, there is an article called "Parallel I/O for the Cortex" (page Cortex_20.jpg). That shows the plug-in header for the 74LS2001. It enables the E-Bus hardware on the Cortex PCB to work.

As far as the component numbering, I believe I recall that when the kits came out, there was kind of a Rev B to the PCB artwork and hence it differed from the original ETI articles.

I have finished scanning the bulk of my documentation and have PM'd Ksarul for his help in getting it up on the FTP site. The Emulator is good enough for sharing too.

Ksarul
July 3rd, 2009, 08:07 PM
I just finished a major documentation upload to WHTech at:

ftp://ftp.whtech.com/Powertran%20Cortex/

Many thanks to TMS9995 for scanning all of this stuff in and making it available to the rest of us.

tms9995
July 4th, 2009, 07:08 AM
Wow, the cover of the first ETI brings back some memories. I was in the computer room at school and my friend came in (he was an ETI subscriber, whereas I had the sister publication Hobby Electronics) and he said, "This is it!" and threw down the magazine in front of me. After he explained all it's attributes, I was sold. Three of us ended up with one. My second machine is the one I bought from my friend when he went off to university.

tms9995
July 4th, 2009, 07:42 AM
I think what is interesting is that if you zoom in on the picture of the ETI cover, there appears to be a chip fitted in the location of the 74LS2001! Despite what Tony said and from my experience that it never existed, something obviously did!

Ksarul
July 4th, 2009, 09:39 AM
I've got the complete internal logic for the 74LS2001--just not a bullet-proof identification of which pin each of those signals need to reside on. Some of it isn't used on the Cortex, which is why I was hoping someone had the signal listing for what belonged on which pin on the chip. With the signal name to actually designated pin position, I can design and program a true replacement for it. . .and then it will be around again. As a side note, there appear to be about 300 of them somewhere in Poland, assuming that they really are the same IC. . .I haven't gotten a response yet from the company that says they have them though, so they may be vaporware.

I'm glad you liked the inclusion of the cover. I have the Aug 1984 issue as well, I just need to finish the scans for it. It contains the rest of the Jun 1984 article along with the board layout for the parallel board.

tms9995
July 4th, 2009, 11:59 AM
I've got the complete internal logic for the 74LS2001--just not a bullet-proof identification of which pin each of those signals need to reside on. Some of it isn't used on the Cortex, which is why I was hoping someone had the signal listing for what belonged on which pin on the chip. With the signal name to actually designated pin position, I can design and program a true replacement for it. . .and then it will be around again. As a side note, there appear to be about 300 of them somewhere in Poland, assuming that they really are the same IC. . .I haven't gotten a response yet from the company that says they have them though, so they may be vaporware.

I'm glad you liked the inclusion of the cover. I have the Aug 1984 issue as well, I just need to finish the scans for it. It contains the rest of the Jun 1984 article along with the board layout for the parallel board.

That's interesting you've got the internals. Tony's post of the E-Bus arbiter has a couple of signals missing (TO & TO EN) and you say yours has got more than the Cortex uses. May be there were 'levels' of arbitration, depending upon the system complexity? Anyway, care to post it for reference?

Ksarul
July 4th, 2009, 01:17 PM
I put a copy of the patent data up on WHTech--diagrams 11a-11c are the Arbiter logic, effectively the 72LS2001 once I know the pin positions.

I also just uploaded the ROM source and dumps of the ROMs

tms9995
July 4th, 2009, 01:40 PM
I put a copy of the patent data up on WHTech--diagrams 11a-11c are the Arbiter logic, effectively the 72LS2001 once I know the pin positions.

I also just uploaded the ROM source and dumps of the ROMs

I just had a quick look - that thing is as complicated as the Cortex! May be just implement Tony's from the E-Bus book and add in the Time Out Enable and Interrupt function :)

tms9995
July 4th, 2009, 02:12 PM
I just had a quick look - that thing is as complicated as the Cortex! May be just implement Tony's from the E-Bus book and add in the Time Out Enable and Interrupt function :)

Went back in and took another look. I guess it's not that bad, but that's definitely the elusive 2001! It has 18 signal pins plus 2 power which is 20 and the Cortex PCB was designed for a 20 pin device! Awesome! Not sure if you can get a 20 pin PAL/GAL/CPLD with that number of latches and product terms?

Ksarul
July 4th, 2009, 07:18 PM
I found reference to an E-Bus controller board someone had for sale a while back for 50 Pounds, so the chip may exist in some form.

If I have to design it into a larger CPLD, I'll just have to do a socket adapter that carries the correct pins down to the 74LS2001 socket. . .I may have to do that anyway, as VCC and Ground aren't where most chips would put them. . .two signals I have been able to trace to their conclusions.

Ksarul
July 12th, 2009, 04:36 PM
I added the Aug 1984 ETI article on the Cortex to the repository on WHTech today.

Ksarul
July 14th, 2009, 07:38 PM
TMS9995's Cortex emulator is now up on WHtech along with a disk image for CDOS 1.20.

Tony Rowell
July 21st, 2009, 02:06 PM
I've found some old polaroids of the very 1st Cortex (when it was called Synapse), they are not in brilliant shape but the I've scanned them and put them on flickr at

http://www.flickr.com/photos/40753974@N08/

tms9995
July 21st, 2009, 06:53 PM
Thanks for those pictures Tony. Looks really weird with a different name on the front panel!

1) I see that it still had Powertran on it at that early stage, so I guess it was at the last minute the name was changed?

2) Who actually made the original? What I mean is that I expect you had it prototyped and working, but did you then send the design to Powertran and they made the PCB and enclosure?

3) Did the original firmware say "Synapse Basic Rev 1.1"?

4) Who came up with the font for the lettering and what's it called?

Ksarul
July 21st, 2009, 07:17 PM
Many thanks for the great historical reference pictures, Tony! The Cortex Rules! :)

JGardner
July 21st, 2009, 08:54 PM
> The Cortex rules...

No Wiki page - Probably should be...

Jack (Too ignorant to take it on...)

Ksarul
August 1st, 2009, 11:13 AM
Just in case it is of use, here are the pin functions for the 74LS2001 as used in the Cortex:

Pin 1: GRANTOUT
Pin 2: BEN
Pin 3:
Pin 4: TO
Pin 5:
Pin 6: RESET
Pin 7: _CLK (LCLK and BCLK tied together, so I will assume LCLK)
Pin 8:
Pin 9: _CLK (LCLK and BCLK tied together, so I will assume BCLK)
Pin 10: GND
Pin 11: TOEN
Pin 12: GRANTIN
Pin 13:
Pin 14: CYEND
Pin 15:
Pin 16: BRQ (BRQ on Cortex Schematics)
Pin 17: VCC
Pin 18: READY
Pin 19: TRACK
Pin 20: BUSYN (TOEN on Cortex Schematics)

The following five signals are not connected to anything in the Cortex, so I haven't got a clue which pins they belong on.

IRQI (I will tentatively put this on Pin 3)
BRQIN (I will tentatively put this on Pin 5)
LOCK (I will tentatively put this on Pin 8 )
PRBQ (I will tentatively put this on Pin 13)
INTEN (I will tentatively put this on Pin 15)

I probably won't find a 20-pin device I can code this into, so I might try and code it into a 32-pin PLCC with a small board to route the pins where I need them to be when they plug into the 74LS2001 socket. Useful side effect will be that I can set up a jumper pad to allow signals to be moved around if need be, especially if it turns out that this chip is useful elsewhere or if we ever come up with an implementation that needs the additional signals.

I now also have a lot of close-up photos of the underside of the Cortex mainboard that I used to help trace everything out. I printed out the upper side on 8 A4 pages and taped them together to get a beautiful large representation of the whole board that is really easy to trace through (though there were a few small areas where the traces didn't scan as well as I'd have liked).

Now I just need to learn how to code CPLDs. . .one task of many on my list of things to do this year.

Cybernaut
August 1st, 2009, 12:54 PM
Hello All

Crikey!, from time to time I goggle "Powertran Cortex" and just get a few hits on the ETI articles. Today I am totally floored by this thread, and the history behind the Cortex.

I have two Cortices (Cortexes). One is a MK1 in a disassembled state, I through away its case, as I could not store it at the time of disassembly in the early 90's.

The second is a MK2 which I built up out one the last kits to be available, all tha is missing on it is the FDD interface that I could never lay my hands on the TMS9909 IC.
I also has a 74LS612 memory mapper chip and the simple E-Bus logic for the parallel interface and the Cortex RGB interface board (I have just now removed its cover).

I also have a stack of documentation for it, I am willing to share it just because this hardware needs to documented and not left to disappear into the mists of time.

As you can guess, I am a closet geek/nerd that preserves old hardware. I have tons of Transputer kit as well, even an Esprit supernode.

By trade I am an electronic design engineer, and the Cortex is partly responsable for it :-)

Best Regards to all Cortex fans/users.

Danny

PS: I would like to buy a TMS9909 and a 9938/9 ic's for my MK2 Cortex, and I'd like an image of CDOS as well.

Cybernaut
August 1st, 2009, 01:01 PM
I have the missing newsletters 5 and 8 in my Cortex stuff. I'll scan them to PDF's if someone wants to post them with the others. I was missing 20 and 21 :-)

Cybernaut
August 1st, 2009, 01:04 PM
and I have newsletter No1 as well, I can't count ;-)

Ksarul
August 1st, 2009, 06:22 PM
Oooohhhh! Please scan those and if you get them to me I'll put them up with the others. Note that the emulator file there has a CDOS 1.20 image. A scan of the Mark II documentation would be a good thing too, assuming it is any different from the files we already have.

Send me a PM on the TMS9909 issue, as I do have one of those I could probably part with. They are a bit hard to find.

Since you mentioned buying one right towards the end, any idea when Powertran stopped selling the MK II kits?

Also, were there any ETI articles other than the ones we've put up so far? You mentioned having the kit for the 9938 mod--getting data on that one would be nice (as I have a spare 9938 that was looking for a good project--unfortunately, I only have the one).

tms9995
August 1st, 2009, 06:58 PM
I have the article for the V9938 board. I was just all 'scanned out' after doing all the other stuff. I'll get to it when I get a chance. I believe there is something in one of the User Group Newsletters that describes the mods necessary to remove the TMS9929 and interface the card in its place.

As for the CDOS disk image, perhaps you could extract all the emulator files so it's a bit more obvious what's in there?

I've been working on the MDEX disk images and also making slight mods to the emulator along the way (I'm doing all the disk work on the emulator to give it a run for its money!). I will send them when I can.

I have some MDEX disks (Forth, Pascal) that don't read well on the Cortex and hence never made it to image form. I might build the improved data separator (also in one of the newsletters). If that's no good I'll have to try and capture the raw data and decode it with a software data separator...

Good work on the '2001! I know ABEL, CUPL and couple of other languages but not done any Verilog or VHDL. I like the Atmel CPLDs.

Welcome to Cybernaut! See, we're all coming out of the closet now!

Cybernaut
August 1st, 2009, 10:05 PM
I fired up the MK2 yesterday for the first time in 14 years, I had to replace a faulty keyboard encoder ic before I could type anything into it. Seem to be working a treat :-)

I realised I have chucked all my old cassette decks (I unintentionally kept a few cassettes), so I have nothing to load the programs on the Cortex with. I'll have to borrow a tape deck and digitise those programs, so that I can load the Cortex from a PC sound i/f.

I have an original glossy sales brochure for the MK2 in colour, the original ETI Digest articles, the original Powertran construction notes for the MK1 and MK2 (not much different from the ETI articles), some details on a Video inteface (not v9938), details on the RGB interface, details on the E-bus parallel interface, one sheet on E-bus from an RS databook. Some sales bumpth from Powertran and uPE. The TI 9900 family databook and another book on the 9980 (I think). A photocopy of a magazine review (PCW?) and a list of benchmark times against other computers from the same period. Plus some correspondance between me and the the user group. I believe thats all I have.

Powertran had given/sold their last remaining stock to the user group. When I bought my MK2 from the user group in March 87 for 80, they only had 3 left. A college friend wanted to build one as well but they had sold all of them by June 87.

Crikey!, Where did I get 80 quid from in 1987 ?, I was a student..........

I rescued the MK1 years later from a skip at the university where I was studying for my MSc, I believe it was chucked out from a robotics lab. I did go skip diving to see if the was anything else in there such as development software, but I drew a blank apart from the MK1.

What I really need is to get the floppy interface going, and then i'll take a look at other HW projects for it (memory expansion etc). I wonder how many Cortex kits Powertran
sold altogether, these must be the one o

I do remember getting hold of a datasheet for a 74HC2000, but the function of that device was an optical encoder and 16 bit counter. I was thinking along the line of similarity between the 74LS612 and 74LS610, hoping the 2000 wasn't to disimilar in function to the 2001.

Cybernaut
August 1st, 2009, 10:07 PM
8) should have left an idiot space (9938 )

Ksarul
August 2nd, 2009, 07:19 AM
On Cortex numbers, I suspect the total isn't very large at all--and the majority of them were probably sold in the Dec 1982 through early 1985 period. I figure sales probably tapered off there, just because a majority of the folks who were comfortable building their own kits would have already purchased theirs, and sales from then to the end point in June 1987 would have tapered off pretty steeply before settling into the slow sales through the User's Group. As Cortex owners were more involved types when it came to hardware, I suspect a significant portion of them were actually IN the User's Group (unlike other systems where such participation rates were in the 1-10 percent range). I read somewhere that there were between 55 and 60 members of the User's Group in 1987--so five to ten times that number is probably the range of all Cortices ever produced. Most of those were probably Mark I machines, which would make the Mark II the truly rare bird. This rarity is actually mirrored in the machines we now know about, though there are probably more machines of both types hiding in lofts. Cybernaut has the only Mark II that came out of the woodwork as a result of this thread, though TMS9995 noted that he also built one for a friend who later trashed it. (Cybernaut, could you put a picture of it up somewhere so that it can be added to the nice file on the Cortex at the Old Computer Museum?) And between the rest of us and other machines that I know of, there are at least 10 documented Mark I machines still out there. Low numbers--but not definitive, as this thread is doing a really good job of finding more Cortices. That said, the lower limit on these machines is probably in the range of 250 or so, with about 50 of those being Mark II machines; and the upper limit is probably about 600, with 100 of those being Mark II machines. I suspect that most of them haven't survived. We'll be pretty lucky if more than 20 Mark I and 5 Mark II machines turn up, though more than that will be a pleasant surprise.

I'll upload the extracted archive of the Emulator files to WHTech later today, TMS9995. I have also found another easy means to transfer files that aren't too large--you can put them onto your LiveDrive at Hotmail and share them out to specific individuals. Good for files larger than the 10 MB you can send as an attachment, up to 100MB.

I'll check to see which of the databooks I already have scans of, Cybernaut (most of them are on WHTech too, in one of the other directories). The Color Sales Brochure for the Mark II would be nice to get a scan of, especially if you can scan in color. Scans of the other articles would be good too (we might have the same parallel interface article you mention up already, as there are two different articles on that subject in the issues of ETI we've unearthed to date). One had a dual joystick interface as well. I don't have the foils for that one, so if it's the one you have, a photo of the underside of the board would be very useful (the top foil can be reconstructed from the picture in the magazine article). A scan of the construction manual for the Mark II, the E-bus extract, the other Video Interface, the sales bumpf, and any of your User Group correspondence that touches on the system itself would be good too, as they may have some data we don't already have.

Ksarul
August 2nd, 2009, 08:58 AM
Glad to see you've got the 9938 mod article too, TMS9995! Your help has been invaluable to rescuing the system documentation for the Cortex. I had to stop adding to my earlier post to keep the 4-year old amused for a while. . .and I really understand that you were scanned out after the last batch of things you scanned in. That was a major contribution all by itself!

Have you tried Anadisk to get good images of the Forth and pascal MDEX disks? That one usually works on almost anything.

I can put anything else that trickles in up on WHTech too, as the data there is starting to show up on Cortex searches as well. My next task is to give an update to the folks at the Old Computer Museum.

Ksarul
August 5th, 2009, 07:39 PM
Courtesy of TMS9995, there are now several MDEX disk images for the Cortex Emulator up on WHTech. Please check out the CORTEX_README file to see how to use them.

Cybernaut
August 6th, 2009, 06:27 AM
Hello all

I hardly ever use forums, so pardon me for being dumb.....

I take it PM is Personal Mail, if so how do you do it from this forum.

I don't have a problem with creating colour scans of everthing Cortex related so that it can go it the public domain and be of use to someone else.
The problem I am having at the moment is no access to an adobe writing software to create PDF's from my scans.
I did have adobe on my work laptop, but it seems to have turned into vapourware!

The only thing I can't scan without destroying it is the doorstop databook on the TMS9900 family, so I am not going to do that one.

I am truly amazed at the Cortex emulator, I had the same program running on the MK2 and the emulator at the same time.
Needless to say the MK2 was faster ;-). The emulator was running on an old lab PC the is a P3 clocked at 1GHz.
I would be interested in seeing seeing the source on how the Cortex emulation is done.

I have beed messing around with FPGA's for the last month and got to wondering about an FPGA replacement for the TMS9995 or even the whole Cortex (inc TMS9909 and the infamous 74LS2001). The are some IP cores avaliable for the TMS9995, but I dare not ask how much they cost for fear of going into a coma.

I am looking at building an updated Cortex on a single eurocard, using original TI chips but modern everthing else including a V9958 or the later V9959. The ancient DRAM would be replaced by a single and not so ancient larger SRAM. The "quaint, ancient, rare as hens teeth, expensive as ????? TMS2564's" will be replaced by a "nice, standard, common as muck, cheap as chips 27c512". The cassette interface can go as well..., LOLMA.

I have been scouring the internet for traces of a TMS9909 and some suitable diskdrive for it (BBC B ones should do the trick).
I have CDOS 1.2 on a 5.25 floppy (I don't know if it is any good).
That reminds me, would it be possible inthe emulator to map the Cortex drive to a physical PC drive?

I have been offered a TMX9909 by a former work colleague, he says it is a prototype TMS9909 but he can't gaurantee it will work in the Cortex or that the chip is in fact a worker.

Regards

Danny

Ksarul
August 6th, 2009, 02:13 PM
It really depends on what format your scan saves them to, Cybernaut--but the OCR software I have will likely read whatever you get into an electronic format--I've even converted JPG pictures into documents with it--that was how I received the Cortex BASIC manual.

I sent you a PM about TMX9909s, so you should see a link under your name at the top left of the screen that will take you to your Private Messages. They will work, though.

The 9995 FPGA cores are expensive, especially when one considers that the chips themselves are still in the $40 to $80 range when they are available (and I have found a number of sources that still have them in quantity). I seem to remember that the cores were in the 3-5K range from the last time that one of my friends went looking.

I like the idea of a Cortex on a Eurocard. That would be a major interesting project. . .and if you are good at FPGA programming, you might want to take on the project of doing a CPLD for the 74LS2001, as we do have enough information now to do something on that front. I will get around to it eventually in any event, but my next year or two are getting pretty full project-wise. ;)

I'm not sure which application TMS9995 used to create his disk images, but one should be able to take them and restore them to physical disks with the appropriate program.

Tony Rowell
August 6th, 2009, 03:31 PM
The are some IP cores avaliable for the TMS9995, but I dare not ask how much they cost for fear of going into a coma.

When I worked for TI a few years ago I wrote a "9900 family member" core in vhdl from scratch, I don't have access to it anymore but there is no real reason that a 9995 core couldn't be written if required, the hard part is verifying it, especially if you want to faithfully emulate the processor when doing strange things, for example:

IDT 'TEST'
*
RORG
LI R1,>0481
X R1
NOP
END

In a real 9995 you never reach the NOP and even NMI doesn't pull you out (a 990/10 needs powering down!!!) and is non-privileged code.
Anyone care to guess why NMI doesn't work?

tms9995
August 7th, 2009, 02:28 PM
When I worked for TI a few years ago I wrote a "9900 family member" core in vhdl from scratch, I don't have access to it anymore but there is no real reason that a 9995 core couldn't be written if required, the hard part is verifying it, especially if you want to faithfully emulate the processor when doing strange things, for example:

IDT 'TEST'
*
RORG
LI R1,>0481
X R1
NOP
END

In a real 9995 you never reach the NOP and even NMI doesn't pull you out (a 990/10 needs powering down!!!) and is non-privileged code.
Anyone care to guess why NMI doesn't work?

My guess is that for NMI (and all other interrupts (excluding Reset)), the interrupt is only acknowledged between instructions and that since the X instruction is executing itself, it never completes.

I tried it on my emulator and it bombs out with a Stack Overflow as the X instruction emulation just keeps calling itself :( I guess this is somewhat acceptable as you have clobbered the CPU at that stage.

Tony Rowell
August 7th, 2009, 02:43 PM
spot on, nasty thing to do to a processor isn't it. A later member of the family made it such that if the target of an X instruction was another X it generated an illegal instruction interrupt to protect itself.
Interesting to hear what your simulator made of it.

tms9995
August 7th, 2009, 03:01 PM
I am truly amazed at the Cortex emulator, I had the same program running on the MK2 and the emulator at the same time.
Needless to say the MK2 was faster ;-). The emulator was running on an old lab PC the is a P3 clocked at 1GHz.
I would be interested in seeing seeing the source on how the Cortex emulation is done.



Thanks for the complement. I guess I could put the source up on WHTech if you want to have a laugh at my first C++/Direct X project! It started out in C as a DOS program. I then made it a Windows App using Borland C++ Builder, added Direct X and then converted it all to classes / C++. I'm quite proud of it really!





I have beed messing around with FPGA's for the last month and got to wondering about an FPGA replacement for the TMS9995 or even the whole Cortex (inc TMS9909 and the infamous 74LS2001). The are some IP cores avaliable for the TMS9995, but I dare not ask how much they cost for fear of going into a coma.



I have dreamt of putting the Cortex on a chip, but I think that's as far as it will go unless I win the lottery and have all the spare time in the World!




I am looking at building an updated Cortex on a single eurocard, using original TI chips but modern everthing else including a V9958 or the later V9959. The ancient DRAM would be replaced by a single and not so ancient larger SRAM. The "quaint, ancient, rare as hens teeth, expensive as ????? TMS2564's" will be replaced by a "nice, standard, common as muck, cheap as chips 27c512". The cassette interface can go as well..., LOLMA.



On both of mine I swapped out the 2564s for a 29F010 (or some FLASH equivalent) and replaced the TMS4500 & 4164s with a 628128 Static Ram (used with the Memory Mapper for 128K). You also get a slight speed increase as the TMS4500 no longer slows down the CPU during refresh (although removing the automatic waitstate generation on the TMS9995 is really the way to go, but that's another story...)





I have been scouring the internet for traces of a TMS9909 and some suitable diskdrive for it (BBC B ones should do the trick).
I have CDOS 1.2 on a 5.25 floppy (I don't know if it is any good).
That reminds me, would it be possible inthe emulator to map the Cortex drive to a physical PC drive?

I have been offered a TMX9909 by a former work colleague, he says it is a prototype TMS9909 but he can't gaurantee it will work in the Cortex or that the chip is in fact a worker.



I'm sure Ksarul has told you in his PM, but my understanding of TI at that time was the chips went TMP, TMX & TMS from prototype through production and I don't think the TMX9909 ever made past TMX :(

For your floppy drives, just use a couple of regular 3.5" PC drives. Cover the hole on the diskette so it thinks it's a 720K (ie non high density) and you're good to go.

Not sure about mapping a PC drive to the Cortex emulator. It's not like it had a hard drive on it to begin with. I have some utilities that can extract a file from a disk image and save it as a PC file. I suppose the other way would be to hijack the cassette save/load?

tms9995
August 7th, 2009, 03:05 PM
I'm not sure which application TMS9995 used to create his disk images, but one should be able to take them and restore them to physical disks with the appropriate program.



I use the CDOS Disk I/O routine to read one sector at a time and send it via the TMS9902 RS232 port to a PC that simply writes it to a file.

tms9995
August 7th, 2009, 03:30 PM
wow! celebrity! I' just off out now, but I'll be adding my questions to the list!

Just wondering if you ever came back ;) ?

nige the hippy
August 7th, 2009, 04:06 PM
I've been reading & downloading the documentation, don't worry. But time is one thing I'm ridiculously short of at the moment. Plus my 'scope did "the big firework" a couple of weeks back and I ended up spending quite some time repairing that. Computery stuff (actually ALL fun stuff :( ) is very much on a back burner till I can get the loft conversion (and heating) fully functional. That should be within the next 6 months or we all freeze and I go loopy. and I WILL be adding my questions to the list!

tms9995
August 7th, 2009, 04:30 PM
I've been reading & downloading the documentation, don't worry. But time is one thing I'm ridiculously short of at the moment. Plus my 'scope did "the big firework" a couple of weeks back and I ended up spending quite some time repairing that. Computery stuff (actually ALL fun stuff :( ) is very much on a back burner till I can get the loft conversion (and heating) fully functional. That should be within the next 6 months or we all freeze and I go loopy. and I WILL be adding my questions to the list!

Cool. Good luck with everything. Just wanted to tease as you were instrumental on getting me to dive in at the deep end! Glad i did though :)

Cybernaut
August 7th, 2009, 04:54 PM
Thanks for the complement. I guess I could put the source up on WHTech if you want to have a laugh at my first C++/Direct X project! It started out in C as a DOS program. I then made it a Windows App using Borland C++ Builder, added Direct X and then converted it all to classes / C++. I'm quite proud of it really!

I wouldn't laugh, I am not that good a programmer that I would even know where to begin writing an emulator for a computer that is over 27 years old.


I have dreamt of putting the Cortex on a chip, but I think that's as far as it will go unless I win the lottery and have all the spare time in the World!

Its been done for the Amiga, Minimeg. Maybe the same hardware could be pressed into service for the FPGA Cortex.


On both of mine I swapped out the 2564s for a 29F010 (or some FLASH equivalent) and replaced the TMS4500 & 4164s with a 628128 Static Ram (used with the Memory Mapper for 128K).

Good minds think alike :D


You also get a slight speed increase as the TMS4500 no longer slows down the CPU during refresh (although removing the automatic waitstate generation on the TMS9995 is really the way to go, but that's another story...)

You learn something new everyday. It's not really new to me, I just forgot that I knew it LOL


I'm sure Ksarul has told you in his PM, but my understanding of TI at that time was the chips went TMP, TMX & TMS from prototype through production and I don't think the TMX9909 ever made past TMX :(

No wonder the bessed things are as rare as the proverbial rocking horse doodoo!


For your floppy drives, just use a couple of regular 3.5" PC drives. Cover the hole on the diskette so it thinks it's a 720K (ie non high density) and you're good to go.

I was thinking about this, but I wasn't to sure that it would work. But then again I have the "chicken and egg syndrome" the only copy I have of CDOS is on a 40T SS SD 5.25" floppy and you need a drive to load it in.

Maybe I could reverse the direction of the your imaging technique, and get the Cortex to read the WHTech CDOS image from the PC via its RS232 port. BTW, my copy of CDOS is actually 1.11 serial No 53 (1984), and not 1.2 as I stated previously.


Not sure about mapping a PC drive to the Cortex emulator. It's not like it had a hard drive on it to begin with. I have some utilities that can extract a file from a disk image and save it as a PC file. I suppose the other way would be to hijack the cassette save/load?

I was thinking more along the lines of mapping a PC floppy or USB stick to one of the floppy drives on the emulator. I wasn't actually thinking about the PC's HDD or full on "map network drive" type of thing. Just simply mapping A: to CD0 :D job done, but I wouldn't where to start with programming that cos it sounds easier said than done.

Stuart
September 7th, 2009, 02:32 PM
Originally Posted by tms9995:
"I'm sure Ksarul has told you in his PM, but my understanding of TI at that time was the chips went TMP, TMX & TMS from prototype through production and I don't think the TMX9909 ever made past TMX"

Here's the chap to ask: <http://www.linkedin.com/in/longley>.

***
New Product Definition Engineer
Texas Instruments - Houston
(Semiconductors industry)

1976 1979 (3 years)

Architect of the TMS9909 Floppy Disk Controller - precursor to modern DSP's, and TMS9911 DMA Controller. Transferred 9909 to design team at TI Bedford, England and evangelized TI processors in Italy. Wrote articles on TMS9940 16-bit microcomputer published internationally, and wrote datasheets and most original content of "The TMS9900 Family System Design Guide". Worked on SPICE models of microprocessors and a high-speed bus architecture.
***

Ksarul
September 7th, 2009, 03:03 PM
I'd seen some posts from him before. He indicated that they were in production for ten years or so in that thread, but everything else I've seen cut that to about five. . .the most recent ones I've seen came from Malaysia and the Philippines though, so they may have been in use longer on that side of the ocean.

andyp
October 14th, 2009, 01:44 PM
I stumbled across this forum the other day after watching a TV program on early PCs.

I'm assuming that most people who still have a Cortex probably have all the documentation that came with it but just in case anyone needs additional info, I've got the following documentation that I could try scanning:

Cortex users manual
The 9900 family data book
The TMS9918A/TMS9928A/TMS9929A Video display processor data manual.
The TMS9995 16 bit microcomputer data manual.
Pages entitled "Reprint of article published in Electronics Today International (with corrections and amendments necessary to be consistant with kit)"
Including :
Block diagram for the complete Cortex.
Circuit diagram of the CPU and DMAC circuitry.
Circuit diagram of the memory section.
Circuit diagram of the video display circuitry.
Circuit diagram of the keyboard and control port.
Circuit diagram of the RS232 and cassette interfaces.
Circuit diagram of the floppy disk controller section.
Component overlay for main board..
Circuit diagram of the E-bus interface.
Circuit diagram of the keyboard.
Circuit diagram of the power supply.
Component overlay for the power supply.
The keyboard overlay.
Circuit diagram of the parrallel I/O board.

Parallel I/O project for the Cortex - ETI September 1985.

Cortex users group news letter # 3

Fig-forth users manual / memory map.

My Powertran Cortex has been tucked away in my loft for the past 20 years and I've always wanted to show my kids my early attempts at writing games for the PC.
The only problem I've got is that at least one of my eproms is faulty and I've never been able to get another copy.
I don't know if you can still find TMS2564 eproms but if necessary I would be willing to sacrifice my fig-forth eproms if somebody was able to reload it with the missing data for me.

Once again, If anyone needs a few pages of the above info scanned and e-mailed, just let me know.

tms9995
October 15th, 2009, 04:01 PM
Hi Andy,

Welcome to our growing little group! I think we now have about 9 known Cortex computers between us which is great.

Have you seen what's on ftp://whtech.com/Powertran%20Cortex/ ? We have quite a lot of info, so please take a look and see what you can add. I believe most of the TI data you mention is also pretty easy to come by.

I think what is really interesting to us is the Forth stuff! I don't know of any copies of this so it would be awesome to copy the ROMs and documentation. Do you have access to an EPROM programmer so you can copy the ROMs to a binary file? If you do, you can also download the CORTEX ROM image from the above link and blow yourself a new copy to get you machine going again in its native environment. The 2564s are kind of rare but it's pretty simple to replace one or all with something fairly modern. Not sure if this is something you are comfortable with? Ksarul is quite good at locating the obsolete ICs.

If not, I could make a copy of the ROMs and program the CORTEX Basic back in. We are all pretty dedicated to the preservation of this machine so I'm sure something can be sorted out.

Thanks again for checking in!

nige the hippy
October 16th, 2009, 02:12 AM
I don't know if you can still find TMS2564 eproms but if necessary I would be willing to sacrifice my fig-forth eproms if somebody was able to reload it with the missing data for me.


If you can't find 2564s You can probably make an adapter for 2764s which are easy to find, with a turned pin socket & some mod wire. the pinout's similar.

if you put your location on, we also know who's up the road and can post you the eproms more easily.

Ksarul
October 17th, 2009, 10:54 AM
Here's an eBay seller with 14 of the 2564's in Great Britain:

http://cgi.ebay.com/IC-TMS2564JL-TMS2564-JL-2564-CDIP28_W0QQitemZ170194793232QQcmdZViewItemQQptZUK_ BOI_Electrical_Components_Supplies_ET?hash=item27a 0667310

Just under four Pounds each. . .

And the FigForth manual and ROM images are a definite high interest item. Most of the rest of the documentation is already up on WHTech, in either ther Cortex or TI-99 folders, as they used the same TI chip set for the most part.

nige the hippy
October 17th, 2009, 12:31 PM
They have the SN74LS612N memory mappers in too item number 180273705894.

I've just rooted out my programmer, apparently it will program 2564s!

andyp
October 19th, 2009, 03:08 PM
Thanks for the replies.

tms 9995,
Unfortunately I don't have access to an Eprom programmer and would need some help to get a new ROM copy.
I followed Nige the hippy's advice and included my location on this reply

Nige the hippy,
If I manage to get hold of a replacement 2564 or a 2764 (if you could supply me with the details of the 2764 adaptor), would I be able to post all the eproms to you so you could make a copy of the figForth Eproms and maybe re-load the original Cortex rom for me - If it's not too much of a hassle.

Ksarul,
Thanks for the ebay link for the 2564's, I'll take a look.

I should be able to scan the Forth User manual myself and e-mail the info.
I notice that the Cortex Forth documentation and Eproms were supplied by Lombard Systems of 18 Lombard Street, Lidlington, Bedford.
At the back of the manual, it states that the glossary supplied, has been taken from public domain publications.
I'm not sure if there are any copyright issues for a user manual dating back to the 1980's or how we would trace them if it was an issue.

Once again, thanks for all the info and advice.

nige the hippy
October 19th, 2009, 11:58 PM
No problem in programming up the 2564s
Can't supply you with details on a 2564-2764 adapter at present, that'll take a bit of work, but should be just a few mod-wires on a socket.

andyp
October 20th, 2009, 11:53 AM
To save all the hassle and extra work for you, I'll order 3 of the 2564's using Ksarul's ebay link and then get in touch again when they arrive.
Thanks for the speedy response and your offer of help.

Stuart
October 20th, 2009, 01:51 PM
At ...

<http://www.forth.org/fig-forth/contents.html>

... there's the source code for a FIG-Forth implementation for the TMS 9900. The Cortex Forth might possibly be a copy of this, with the Cortex-specific keyboard input / screen output routines. There is loads of Forth documentation elsewhere on that site.

Stuart.

Ksarul
October 23rd, 2009, 03:13 PM
Thanks for the figFORTH link, Stuart!

AndyP, if you can get the manual scanned, I can put it up with the other documents on WHTech. If we ever get questions about documents posted there, we remove them immediately. Most of the companies involved are so long-gone that there is no trace of them anymore--but we always respect their wishes when made known.

I'm just glad there is so much still out there for the Cortex! :)

Ksarul
October 25th, 2009, 08:18 AM
Here are some great prices on 9995s, 9901s, and 9902s, for those needing spare parts for your Cortex!

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130339760339

I found these on Fleabay this morning. . .

tms9995
October 25th, 2009, 09:51 AM
Excellent find! I looked last week when you found the 2564's and it was something like $95 each! I just ordered 3...

Ksarul
October 27th, 2009, 06:12 AM
He seems to have quite a few of them, as he posted more of them this week.

nige the hippy
October 27th, 2009, 07:44 AM
someone's selling another!

ebay uk item number 320440875280

is that 13 now?

tms9995
October 27th, 2009, 10:26 AM
Looks in good condition but doesn't appear to have the disk chips or RGB/V9938. Probably cost a fortune to ship to the US too :(

Hugo Bento
October 27th, 2009, 04:26 PM
Great, finally i find something about Cortex.
Was just talking to my dad, while he repaired his Oscilloscope, and we talked about Cortex. Made me quick google it, and great, new info.

You guys should really make a Wikipedia Page for Cortex. It deserves it.

So my dad has a cortex. He got it when he was working at TI. :rolleyes:
It was a great computer, he assembled it, and he thought me and my brother at the age of 8-9 how to work with it, and how to do some light programing in Basic.
It was an wonderful computer.
Specially the games that we had. We loved to play those old Golf and platforms games.
Thanks Tony Rowell, the Cortex made quite an impact in my family life.

Anyway my main interest in cortex is this little gem of a platform game, called Burglar. Where a small fat guy much like Mario goes around collecting sacks of money, keys, jumping on conveyor belts, walking on degrading platforms etc.
For me this game is truly a masterpiece.

Does anyone knows anything about this game ? Who wrote it, if there is any port to another platform, or an emulator that can run it ?

nige the hippy
October 28th, 2009, 02:34 AM
Looks in good condition but doesn't appear to have the disk chips or RGB/V9938. Probably cost a fortune to ship to the US too :(
Big toroidal transformer in the back :( at least there wouldn't be the weight of the disk drives :roll:

Ksarul
October 28th, 2009, 08:19 PM
And it looks like several folks are interested in it too. . .maybe we could replicate the 9938/9958 mod. board. I have several 9958s. . .and one V9990. We'd just need the layout redone to do a short run of the boards. I could do that using ExpressPCB if we had a copy of the original layout.

That one at least has the cutouts for the disk drives in it--mine has a solid brushed aluminum plate across the entire front of the machine.

andyp
October 31st, 2009, 10:50 AM
I still have a copy of the Burglar game on cassette but I don't know who wrote it.
My Cortex doesn't have any disk drives so when I eventually get it working I'll have to use an old tape player.

Has anyone tried using an MP3 player instead of a cassette, do you think this would work or would there be too much data lost in the file conversion.
Or does anyone know of a particular format that would work.

nige the hippy
October 31st, 2009, 03:26 PM
Apparently mp3 does work, although it shouldn't. I personally would stick the tape in a tapedeck connected to the pc, and record it as a .wav then email it to the chap who was looking for it (and the other chap with the archive, so we can all play it). wav's preserve pretty well all the data, so even if the tape has degraded a bit it might still be possible to rebuild it, I'm less sure how the mp3 compression would cope with dropouts & print through, which tape is subject to.
(I've been to a wedding today so a bit worse for wear!)

Ksarul
November 1st, 2009, 10:33 AM
Looks like Cortices are going up a bit in price too--the one on Ebay sold for more than twice what the last two sold for. Was the winner anyone on the list here? If not, we should probably try and get them in.

Also, the guy on Ebay that had the TI chips seems to have more of them. I just purchased a lot of TIM9904s from him, along with some TMS9901s.

nige the hippy
November 2nd, 2009, 01:22 PM
quick check... the rom files, there are 6 extra bytes, is it a crc/checksum at the end, or is the "ROM1 " at the beginning the extraeneous data?

EDIT*****

I've just answered the question, the "ROM1 " at the beginning should probably be removed from the binaries, I've just checked the source code listings and it's offset by 6 bytes.

Could have been a waste of postage andyp!

andyp
November 3rd, 2009, 04:05 AM
Nige the hippy,

Eproms in the post and on their way.
I decided on recorded delivery to prevent them getting lost, I hope this doesn't cause you any additional hassle.

tms9995
November 3rd, 2009, 07:44 AM
quick check... the rom files, there are 6 extra bytes, is it a crc/checksum at the end, or is the "ROM1 " at the beginning the extraeneous data?

EDIT*****

I've just answered the question, the "ROM1 " at the beginning should probably be removed from the binaries, I've just checked the source code listings and it's offset by 6 bytes.

Could have been a waste of postage andyp!

Just to be sure, the CORTEX.BIN file in the emulator directory is a pure binary image of the 3 eproms plus a 4th 'blank' one to take it up to 32K. There are no padding or checksum bytes so the 3 ROM files can easily be correlated with it to confirm you have the right data in the programmer etc.

antiquekid3
November 11th, 2009, 12:09 PM
Apparently mp3 does work, although it shouldn't. I personally would stick the tape in a tapedeck connected to the pc, and record it as a .wav then email it to the chap who was looking for it (and the other chap with the archive, so we can all play it). wav's preserve pretty well all the data, so even if the tape has degraded a bit it might still be possible to rebuild it, I'm less sure how the mp3 compression would cope with dropouts & print through, which tape is subject to.
(I've been to a wedding today so a bit worse for wear!)

I have a SWTPC 6800 with the tape interface, and instead of recording to a tape deck, I tried recording to my MacBook using Audacity. After recording, I exported the file as an MP3 into iTunes. I have had no problems so far reading an MP3 file and sending it to the SWTPC. I don't know if the Cortex uses the 300 baud Kansas City standard or not, but if it does, it's just having to distinguish between two frequencies, which aren't that hard to reconstruct from an MP3 file.

I think it'd be nice to have a website devoted to these sound files for different machines, along with the source code.

Kyle

andyp
November 12th, 2009, 09:29 AM
I have a SWTPC 6800 with the tape interface, and instead of recording to a tape deck, I tried recording to my MacBook using Audacity. After recording, I exported the file as an MP3 into iTunes. I have had no problems so far reading an MP3 file and sending it to the SWTPC. I don't know if the Cortex uses the 300 baud Kansas City standard or not, but if it does, it's just having to distinguish between two frequencies, which aren't that hard to reconstruct from an MP3 file.

I think it'd be nice to have a website devoted to these sound files for different machines, along with the source code.

Kyle

I don't know what standard the Cortex uses but I've got Audacity on my PC, so I'll give it a go - Thanks for the info

Ksarul
November 24th, 2009, 06:56 PM
I'm going to try and get the rest of the documentation folks have provided up onto WHTech over the next few days. RL has been keeping me waaaayyy tooo busy of late. . .no time at all for my hobby. :(

Ksarul
January 11th, 2010, 06:58 PM
After a careful look, I am now busy inputting the Cortex Fig-Forth manual pages into a single, edited document. I should have it finished before the weekend and then I can put it up on WHTech. The job and school had me waaaaayyyyy too busy this fall, but the tempo is down now, so I have time for my hobbies again :)

I wonder if NigeThe Hippy had any luck reading the ROMs for it?

nige the hippy
January 12th, 2010, 04:04 AM
roms- - I have done a bit, the eprom programmer is at this moment in pieces in front of me, it puts the right programming voltage on the right pin at the right time etc, but for some reason the 5v looks too low. I'm tracing through the pcb to work out why.
I'm still too nervous to put the original forth eproms in the machine before it's 100%. There's a possible alternative (old school) solution on the near horizon, I'm keeping my fingers crossed!

Ksarul
January 16th, 2010, 07:07 AM
I put a nice PDF of the Cortex FIG-Forth manual up on WHTech today, along with instructions on using the TMD2797 Disk Controller chip, the TMD9929 RGB interface, and the V9938 mod. Many thanks to ANDYP and TMS9995 for taking the time to make the original scans. I took the FIG-Forth manual and redid it to make it the highest quality manual possible (like I did for the original Cortex BASIC manual a while back). I'll probably do the same for the MDEX manual next. . .

nige the hippy
January 16th, 2010, 08:24 AM
I'm now the proud owner of a decent 1980s eprom/pla/prom/uC burner, (Stag PPZ) with quite a few pods. I pick it up monday, apparently it nearly all works (although I can pretty well guarantee that the 2564 will lie just outside that nearly)

nige the hippy
January 18th, 2010, 10:20 AM
well as luck would have it, the chap tested it on a 2564, and it was fine
I've uploaded the 2 forth roms, although I'm not sure what order they should go in (if at all) I suspect the "red" one is second as it's only 1/2 full.
files attatched, in intel hex. (additional ".txt" added in order to upload)

Have a look, & see if it makes sense.


Incidentally, I'll get the 3 O/S roms going as soon as I've figured out why I'm not transferring data the other way

andyp
January 18th, 2010, 01:08 PM
well as luck would have it, the chap tested it on a 2564, and it was fine
I've uploaded the 2 forth roms, although I'm not sure what order they should go in (if at all) I suspect the "red" one is second as it's only 1/2 full.
files attatched, in intel hex. (additional ".txt" added in order to upload)

Have a look, & see if it makes sense.


Incidentally, I'll get the 3 O/S roms going as soon as I've figured out why I'm not transferring data the other way

Great news.

According to the original installation instructions, the eprom marked >0000 goes into SOCKET IC47 and the eprom marked >2000 into SOCKET IC46.
From memory I think they are numbered - (very small in biro)
I've had a look at your attached files but have to confess they don't mean a lot to me.
I've got a copy of the memory map, I'll send this to you on seperate e-mail, it might help.

andyp
January 18th, 2010, 02:07 PM
Can't seem to attach the memory map file as promised - Sorry.
However, Ksarul has placed a copy of it on WHTech.

nige the hippy
January 18th, 2010, 02:23 PM
No chance to look at the memory map, but what you say now makes sense - I ought to rename the files, green is >0, red is >2000.
And I've now written the OS eproms.
I'll get them in the post ASAP.

tms9995
January 18th, 2010, 03:20 PM
Way to go guys!

I have attached FORTHROM.zip which contains FORTHROM.BIN. If you save this into the emulator directory as CORTEX.BIN (having renamed the original as CORTEXROM.BIN) you can check it out using the emulator! Only gave it a quick once-over, but seems to work! 27 years after I got the computer I've seen something new on it. Thanks to all.

Ksarul
January 18th, 2010, 06:46 PM
Excellent news! Now we have FIG-Forth ROM dumps for both the emulator and the hardware! Thanks to everyone, and especially to Andyp for keeping his copy all these years!

Ksarul
January 18th, 2010, 07:01 PM
Maybe we can get Cybernaut energized to scan the documentation items he mentioned having that were missing from the archives as well. At this rate, in a year or so we'll have everything there ever was for the Cortex preserved online. . .

andyp
January 25th, 2010, 10:01 AM
Just received my shiny new Eproms from "Nige the Hippy" and am about to install them.
Just want to ensure i put the correct Eprom in the correct socket.
The sockets are labeled 45, 46 + 47 and the Eproms are labeled 1,2 and 3.
I was going to put them in number order then I realised that the Forth Eproms seem to number the other way around i.e. 1st Eprom in skt 47.
Can anyone advise?
Thanks

tms9995
January 25th, 2010, 12:01 PM
Had a quick look at the circuit diagram and IC47 is the first, IC46 is the second and IC45 is the third. Good luck and let us know you have a working Cortex Basic!

andyp
January 25th, 2010, 01:12 PM
Had a quick look at the circuit diagram and IC47 is the first, IC46 is the second and IC45 is the third. Good luck and let us know you have a working Cortex Basic!

Thanks for the info. I put the new eproms in and no luck! - All I got was a constant tone and the "MEM" LED lit.
I then decided to fit my Forth eproms and got similar results. After a few resets I got the LEDs to stabilize and ended up with the "RUN" LED lit but then couldn't get any text prompt on the flickering video output. The whole set-up seems to be a bit unstable and the LEDs keep changing state if I move the chassis. I'll have to check the supply voltages and hunt around for loose connections etc. I seem to remember that the video output was always a bit unreliable.
I like a challenge !!!

andyp
January 26th, 2010, 12:47 PM
I've just had another look at my dead Cortex and have got a few questions:

What is the normal sequence for the front panel LEDs after a reset - I can't remember and can't find my original guide, but I'm assuming that a healthy Cortex just has the "BASIC" LED lit if all is OK. Mine seems to mostly display a dim / flickering "RUN" led and constant "MEM" led, if this means anything.
I've checked my PSU output and measured: + 4.3v, +11.73v, -12.1v using the 0 volt line on the PSU output connector. - ( For some strange reason if I measure the voltages using the chassis earth, I get + 4.94v, +11.92v, -12.02v ).
Does anyone know what the tolerances are on these voltages? -- I suppose I could get a PSU from an old PC just to be sure.
Last question - When I put it together in the 1980's, I decided to use dual-contact sockets in every IC position, in case I had problems and needed to replace any ICs.
Do you think that the contacts on these socket could have oxidised over 27 years and maybe I should remove and re-seat each IC in-turn, or would I be wasting my time.

Any advice would be appreciated.

tms9995
January 26th, 2010, 05:34 PM
I've just had another look at my dead Cortex and have got a few questions:

What is the normal sequence for the front panel LEDs after a reset - I can't remember and can't find my original guide, but I'm assuming that a healthy Cortex just has the "BASIC" LED lit if all is OK. Mine seems to mostly display a dim / flickering "RUN" led and constant "MEM" led, if this means anything.
I've checked my PSU output and measured: + 4.3v, +11.73v, -12.1v using the 0 volt line on the PSU output connector. - ( For some strange reason if I measure the voltages using the chassis earth, I get + 4.94v, +11.92v, -12.02v ).
Does anyone know what the tolerances are on these voltages? -- I suppose I could get a PSU from an old PC just to be sure.
Last question - When I put it together in the 1980's, I decided to use dual-contact sockets in every IC position, in case I had problems and needed to replace any ICs.
Do you think that the contacts on these socket could have oxidised over 27 years and maybe I should remove and re-seat each IC in-turn, or would I be wasting my time.

Any advice would be appreciated.

The power-on sequence takes about a second and involves mainly the RUN LED being lit until the initialisation is complete whereby it will sit at IDLE with the BASIC LED flashing about once per second. The MEM LED indicates the Memory Mapper has been turned on with a CKON instruction and doesn't sound normal for powering on.

There should be a good solid 5V measured on the board (eg across the power pins of any IC). Maybe you've got a bunch of ripple due to bad PSU capacitors? As far as the ICs go, I would definitely recommend reseating them as they do tend to oxidise up.

nige the hippy
January 27th, 2010, 02:22 AM
Ditto, I would also add check the rectifier is happy, it sounds to me like terrible ripple is the first problem to look at.

andyp
January 27th, 2010, 08:51 AM
Thanks guys,

I'll have another look at the 5 volts as suggested and keep you posted.

andyp
January 27th, 2010, 11:05 AM
Guys,

I checked the 5 volt supply across the pins on an IC and got 4.4v and the voltage at the fuse before the 7805 is 10.2v.
I can probably get hold of an oscilloscope to see if there is any ripple and I think I've got a spare 7805 but what's got me a little confused is I appear to have a different set of component lists / schematic diagrams to those listed on WHTech. I can only assume that they were issued to me in the kit from Powertran. My sheets have additional hand written notes on them and there is a note printed on the power supply overlay saying :
* = vertically mounted 4R7 resistor (Drawn on overlay adjacent to BASE lead of Q1) and + = vertically mounted 100R resistor (Drawn on overlay between the COLLECTOR lead of Q1 and the output lead of the 7805 IC1) plus the comment "Fit only if the voltage is low (less than 4.8v on the TMS9928 )".
Looking at my power supply I must have experienced low voltage issues when I first built it because I have the 4R7 resistor in place but I then appear to have by-passed it at a later date probably because it didn't work and I couldn't be bothered to take the PSU out again to remove it.
It's all very confusing because they have not modified the circuit diagram so there is no way of telling exactly where these two resistors were intended to be connected. (I seem to have tried to fit the 4R7 in series with the 0 volt line of the 7805)
I realise that this description is probably very confusing, but using your expertise, where do you think a 4R7 resistor and a 100R resistor should be fitted to increase the ouput voltage - I am assuming that as they state the resistors are vertically mounted they are intended to be in series with two of the Q1 / IC1 leads but I don't know which ones.
The PSU component overlay also states that it is "ISSUE B" PCB.

Ksarul
January 27th, 2010, 06:59 PM
On your schematic differences, there were apparently at least three different revisions of the board, but I have never seen a set of schematics reflecting all of the differences between versions Andy. If yours are different than the ones we have, it might be a good idea to scan them in too as a help to any others who may have that board revision. I'll have a look at mine to see if the resistors are in place as you describe.

nige the hippy
January 28th, 2010, 03:42 AM
Interesting & confusing. I understand the circuit in the schematic. So I hope you won't mind me talking through it in order to get a better idea of what's going on.
the 7805 is using it's output to monitor the 5v rail, if it's a bit low, it supplies a little current. it gets this current from the base of Q1, thereby turning it on a bit, increasing the current flowing through Q1 to the collector, and out onto the 5V rail.

I'd be separating the psu by now! It's all too easy to put a high voltage onto the main board. Load is crucial to the operation of the circuit so use a dummy load like a car headlight/brake light bulb.

I'd go back to the original circuit, Isolate the 7805 reg from the transistor output & test the regulator gives 5V. It's possible that the input voltage is not high enough to operate it properly. If it doesn't give 5V perhaps you should replace it with a "low dropout voltage" version.

(More thoughts in a minute when I've threaded this earth wire & picked my daughter up!)

nige the hippy
January 28th, 2010, 08:21 AM
AAAhhh if you've bypassed the 4.7ohm resistor between +ve & the base of q1, you've turned Q1 off! Which may mean that the computer is running off just (a very stressed) 7805.

(now covered in mouse poop, & going to pick other daughter up)

andyp
January 28th, 2010, 03:49 PM
Ksarul,

I've since noticed that the pages I have state that they are:
"Reprint of article published in Electronics Today International ( With corrections and amendments necessary to be consistent with kit )
When I get to grips with my 5 volt issue, I'll scan and send them to you.

Nige,

Followed your advice and isolated the PSU from the main board and used a car light bulb as a load ( Draws about 1.3 amps at 5 volts )
I've now removed the whole back panel / PSU / transformer, to make it easier to work on.
Had some more strange voltage measurements - When I first checked the 5 volt on the output connector I had 4.7v but if I checked it at the floppy disk supply connector I had 5.02v ?? - Even though the 2 supplys come from the same point on the circuit ?? And with power off, when I check for continuity between the floppy 5v and the main board 5v plus 0v to 0v on the different connectors all is OK !
I then removed the PSU board and decided to tidy it up and remove the by-passed resistor and investigate where these add on resistors were designed to go.
Judging by the pre-drilled holes in the PCB, the resistors referred to in my amended notes are designed to go as follows:
100R between the +5 volt output of the 7805 and the CMN terminal of the 7805.
4R7 between the CMN terminal of the 7805 and the 0 volt rail. ( This was the one I listed as by-passed in my earlier post and it looks like I had also cut the 2nd 100R resistor off the PCB)
I assume that these 2 additional resistors are intended to bias the 7805 CMN terminal to approx + 0.3 volts to increase the output slightly if required.
With the 4R7 resistor removed, the CMN lead on the original 7805 was now too short to re-solder to the board, so I have replaced it with one from Maplin (QL31J) - Not sure if this is a "low dropout voltage" version. Everything is now as per the original circuit diagram ( i.e. All additional resistors removed) and the fault is still there.
What I find most puzzling is the voltage reduces bit by bit as I get closer to the main board ICs.
These voltages are approximate (from memory) but there is 5.02v at the PSU floppy connector (not used), there is a bit less at the PSU main board connector 4.8v, a bit less where the supply cable is connected to the main board 4.6v and even less across the main board ICs 4.4v.
I can't see any evidence of dry joints and as the PSU floppy connector seems to have a rock solid output of 5.02v, I was thinking of trying to feed the main board from that point.
PS. I hope you don't mind me posting all this on the forum.

Ksarul
January 28th, 2010, 07:12 PM
Posting the data here is a very good thing, Andy--especially if it helps someone else avoid a similar problem once the final details of the isolation process are completely documented here. I'll have to go into mine soon to add the floppy controller and the memory mapper sections of my board, so all the data you've posted here may come in very useful, as it will tell me both normal and abnormal behavior for the motherboard. If your schematics say they are the corrected ones, it would be very good to put them up on WHTech.

andyp
February 2nd, 2010, 12:36 PM
A quick update on my dead / dying Cortex and a plea for advice on what to check next.
As per my earlier post, after tidying up the PSU board I could only achieve 4.4 volts on the main board.
With the bias resistors re-fitted, as per the construction guide and a new 7805, I achieved 5.25v at the PSU output and 4.9 Volts on the main board.
All the ICs were then removed, cleaned with a fibreglass brush and re-seated
I then fitted my new BASIC eproms and applied power. The Cortex gave a continual alarm tone, the "RUN" light flickered and the "MEM" light was lit.
I then fitted my known good FORTH eproms and the fault was still there.
Assuming the PSU could still be suspect, I took a known good PSU from a working desktop PC, checked the output and cabled it to the Cortex.
From memory I was then seeing +12v, -11.65v and +5.25v at the PSU output and +4.9v across the ICs on the main board.
With power supplied from the new PSU the "RUN" and "MEM" lights were lit as before but there wasn't the same continuous tone from the speaker. However I did hear a faint "crackling" sound from the speaker after pressing the reset button, this sound would disappear when the LEDs had settled down.
Being a total novice when it comes to this sort of thing, can anyone suggest what I should be checking next.
I am working on the following assumptions
1) If I continue using the desktop PSU we can eliminate any power issues.
2) At this stage I don't need the video output.
3) At this stage I don't need the cassette interface.
4) At this stage I don't need the E-bus.
5) At this stage I don't need the keyboard.

Could any of the above interfaces be dragging the system down? I can unplug the keyboard but should I be removing any ICs to the isolate the others or is this a waste of time.
I have access to a DVM, a logic probe and possibly a scope - Can anyone suggest a way foward?

Stuart
February 7th, 2010, 11:11 AM
Andy,

Could someone perhaps supply you with a single EPROM containing a small program that does nothing other than cycle one of the LEDs on and off? This would confirm that a bare minimum of circuitry was working. Whether this works or not, it would give you a known base to start testing from.

I'd also be inclined to replace IC44 and IC97 - a pair of 74LS245s that you can get off Ebay for a few quid. The '245s are quite prone to blowing, as far as I understand.

Stuart.

andyp
February 10th, 2010, 01:11 PM
Stuart, - Thanks for the info, I'll follow your advice and get some spare 74LS245s.

I notice from the ETI description that one of the 74LS245s is a data buffer connected to the DRAM chips and the other is used by the EBUS - Could I not just swap these around or try them one at a time in position #44 to see if it makes a difference. Or do they both have to be fitted at the same time?

Does anyone know if ALL the DRAM chips have to be fitted for correct operation and if one of these memory chips was to be faulty could this be preventing my initial start-up sequence
It occurred to me that if the contents of the eproms are transferred into the DRAM at start up, then in theory could I get away with fitting 3 x TMS4164 at a time.
I could then try different combinations of my 8 DRAM chips in batches of 3 to eliminate them as faulty. Would this be a usefull exercise?

Stuart
February 10th, 2010, 03:50 PM
The 74LS245 at position IC44 is the critical one as it buffers the DRAMs. You could try swapping them over. If IC97 is not fitted, that shouldn't be a problem as far as I can see.

Each DRAM is only 1 bit wide - so you always need 8 of them to form an 8-bit byte. If any one of them is bad, it is possible that could be causing the problem (or of course it could be any of the other chips on the board).

The processor itself has 256 bytes of RAM, so it should be possible to develop a routine to test the DRAM, with the routine in EPROM and using the processor RAM for workspace, and giving feedback through one of the LEDs. If no one else chips in with an offer of help then I'll see if I can get a TMS2564 and cobble it to work on my programming board, which supports only up to a 2532. What would be useful is if a UK owner was able to test any such routine on a known-working Cortex just to make sure it works first.

I'm up in Southampton. You got a new Maplins in Barnstable last year was it?

Stuart.

nige the hippy
February 11th, 2010, 05:28 AM
I'm up in Southampton. You got a new Maplins in Barnstable last year was it?
Stuart.

However they don't actually sell anything useful these days!

1) if you need your 2564 programming I should have a fast turnaround this time.
2) I have a small pot of MCM6665s which as far as I can tell are 4164 compatible. I can test 8 and put them in some antistat foam in the post.

Stuart
February 11th, 2010, 12:33 PM
Makes sense to try a new set of 4164s if they are handy.

Andy, when you tried your Basic EPROMs, did any of the LEDs change state once the buzzer started? Looking at the Cortex Basic ROM code, the first thing it does at power-on is copy the EPROM to RAM and it creates a checksum of the EPROMs as it goes. If the checksum fails, it switches on the buzzer and locks the system (so shouldn't get any LEDs changing state after this point - if this is what your system is doing).

andyp
February 11th, 2010, 03:29 PM
Nige / Stuart, Thanks for the response and sorry for the stupid question about the DRAMs, you can probably tell this isn't my area of expertise!

I've just tried both of my 74LS245s in position # 44 and I get the same results as before.

I've been looking through the original build instructions and realise that in my haste to build the computer all those years ago, I don't appear to have soldered the "through holes" that make the connections between the 2 sides of the PCB. So the dilemma I have now is do I assume that the PCB, that I have had working in the past, is good and I have a component fault OR do I solder all the holes and risk possibly introducing a seperate fault between the tracks on the PCB when soldering. Any thoughts?

Nige - If I could borrow a set of your MCM6665s for fault finding, that would be great - Thanks very much.
Stuart - I've just checked the forum again and have seen your question about the LEDs. Unfortunately I've just dismantled everything again and placed it out of harms way, so I can't say for certain if the LEDs stop when the buzzer sounds - From memory, the symptoms change each time I press the reset button / apply power. Sometimes I get no buzzing and just the MEM and RUN lights lit. Other times the speaker crackles, the RUN light goes dim and flickers and the MEM led lights. And on some occasions I see the IDLE or BASIC led lit on their own - It just seems a bit unstable. The buzzer was definately constant after every reset before I resolved the LOW VOLTs issue. I'll give you a more accurate report when I check it again over the weekend
Your idea of using a modified single EPROM sounds interesting and I actually have 2 of my original 2564s spare (and I assume serviceable) but I would not know how to set one up.
Once again thanks to you both for assisting me with this, I certainly need the help!

andyp
February 21st, 2010, 09:50 AM
Stuart,
I almost replied to your question using my fig forth eproms for the LED sequence test.
This is what I saw using both sets of eproms.
Using the Fig Forth eproms, there doesn't seem to be a set pattern. Each time I press the reset button the sequence is slightly different. The long beeps and very short beeps seem to coincide with the MEM led lighting but on several occasions the leds will continue to change after the 1st beep has been heard almost as if the system is initiating another reset itself.
On occasions I also see a random checkerboard pattern on the screen.
Using the Basic Eproms, the sequence is always the same - Which would tend to match what you were saying.
With the reset button held in, the "MEM" light is lit. When the reset button is released the MEM light stays on, the RUN light comes on for approx 1 second and then I get a continuous tone plus MEM led.
Do these symptoms confirm that the checksum is wrong and if so what do you think I should check next OR shall I remove the main board and start to solder the "front to back" connecting holes.
One more thing, I managed to get hold of a frequency counter and have checked the 12Mhz source and the CLK on ICs 11 and 32, all seems OK.

Thanks

Andy

Stuart
February 21st, 2010, 12:04 PM
You do get a continuous tone if the checksum fails with the BASIC ROMs. The MEM LED staying on is very suspicious - according to the circuit diagram and the software it should go off when the RESET button is released. Try swapping IC17 (74LS74) with another chip on the board of the same type, and also try swapping IC15 (7 4 L S 1 3 8 ) - these two chips control the MEM LED. Also worth checking the 5V supply across these two chips as well, just to make sure you've got the power supply sorted.

Is the board fitted in a metal case, with spacers between the case and the board? Might just be worth loosening the board and checking that no screws or anything have got stuck between them in years gone past.

Let us know how you get on.

Stuart.

nige the hippy
February 21st, 2010, 01:33 PM
sorry Andy, haven't checked the thread for a few days, a bit of a family crisis on. I'll get 8 chips in the post as soon as I can. it feels a bit rammy to me, but that's purely a guess!

andyp
February 21st, 2010, 01:40 PM
Thanks Guys,
I'll hang fire on the soldering and try what you've suggested.

andyp
February 23rd, 2010, 10:11 AM
Stuart,
I've just done the IC swap for positions 15 + 17 and the fault is the same.
(I had a spare 74LS138 and I exchanged the ICs in sockets 17 + 92)
The voltage across the two was 4.91v.
My circuit diagrams have different names for the LEDs but I'm assuming from the wiring to the front panel that the LEDs are as follows:

IAQ = RUN = LED3
MAP = BASIC = LED2
TIME = MEM = LED4
IDLE = IDLE =LED1

So my diagrams seem to indicate that the MEM LED is connected to IC64.

I've also checked under the main board and there does seem to be anything touching the tracks.

Stuart
February 23rd, 2010, 12:10 PM
Hi Andy,

Your labelling of the LEDs doesn't seem to match the wiring given in the contruction instructions. According to the instructions:

LED1 = IDLE on circuit diagram = IDLE on front panel (2nd LED from left)
LED2 = MAP on circuit diagram = MEM on front panel (3rd LED from left)
LED3 = IAQ on circuit diagram = RUN on front panel (left-most LED)
LED4 = TIME on circuit diagram = BASIC on front panel (right-most LED)

Do you want to check your wiring and see what is connected where? IC64 drives the TIME/BASIC LED, and that *should* be lit on and after a reset. I think the LED problem is going to be just a wiring or labelling error, which leaves the problem with the EPROMs.

The EPROMs were blown by Nige? When you've received and tried the RAMs he's sending you, perhaps send the EPROMs back and ask if Nige can test them in his Cortex? That would rule out any problems with the EPROMs or the source files Nige used to program them.

Is there a memory map of the Cortex available? Anyone know where the 256 bytes of memory on the processor itself is located? On boot the workspace is at >F0DC - is this in the on-chip RAM?

nige the hippy
February 23rd, 2010, 12:19 PM
Only problem with my cortex is that I don't know if it's a go-er yet. I daren't just power it up, and I still haven't a space I can strip it sufficiently to test it. I suppose I could pull my roms & check them against the images I have... I'm sorry about this there's a bit going on at the mo to say the least......

edit.... oh go on then, it's only 8:20 I'll go upstairs, finish writing the disks, put the sirius away & get the cortex out!

Stuart
February 23rd, 2010, 12:59 PM
Sorry Nige, didn't mean to impose on you - especially on someone else's behalf! I didn't realise your Cortex was in an 'unknown' state. If Andy's Cortex has been stuck in a cupboard for donkey's years then I'm sure another couple of weeks won't matter if you're up to you eyes with things at the moment. ;-)

Stuart.

andyp
February 23rd, 2010, 01:54 PM
Stuart - I'll go and have another check to see if I've got it wrong.
The LED numbering and circuit board labels match your description but I might have the LED wires in the wrong position on the plug.
I don't have the original construction info for the LEDs so maybe I always had it connected incorrectly.
With regard to the eproms from Nige, I'm pretty sure that they aren't the cause of the problem because I get similar issues when using the forth eproms.
And the forth eproms have been recently read/copied by Nige and the code used in the emulator.

Nige - Stuart's right, there's no rush to get my Cortex fixed. I'm greatful for the help but you sound pretty busy at the moment so I'm more than happy to wait.

andyp
February 23rd, 2010, 02:20 PM
Stuart - Just checked my front panel LEDs and I do have the plug configured as follows:
PCB IAQ = RUN
PCB MAP = BASIC
PCB TIME = MEM
PCB IDLE = IDLE
PCB 5V = All LEDs
So it appears that it has always been wrong and all I've succeeded in doing is misleading you - So I suppose my original post should read:
With the reset button held in, the "BASIC" light is lit. When the reset button is released the BASIC light stays on, the RUN light comes on for approx 1 second and then I get a continuous tone plus BASIC led.
I now feeling guilty about taking up everyones time.

Stuart
February 23rd, 2010, 02:29 PM
Andy, have sent you a private mail (not to call you a doughnut!)

Stuart.

nige the hippy
February 23rd, 2010, 02:53 PM
I've checked the psu (a bit of a pain because someone cut the mains lead off), and shorts on the motherboard, both ok. however I've got to the stage where I need an aerial lead, which is in the shed, and it's sleeting.
It's almost but not entirely tempting, but it's quite a way to the shed across a couple of slippy planks over the ex-pond, in the dark. so i'm staying warm till tomorrow morning.

It's always a fight between doing the washing/washing up, feeding the children/cat, putting another bit of ring-main/plumbing/plasterboard in, being sociable or fixing an "orange glowy thing" (wife's reference to Toshiba3100 etc), as the latter is something I enjoy & me being the result of a protestant upbringing, the latter usually misses out ;-(

nige the hippy
February 24th, 2010, 05:05 AM
It works!!! .... well almost, colour/vertical sync are a bit out of sorts on the UHF adapter. I haven't tried component video out yet. but I think we have a test-bed machine. Ran a sample basic program, fine.

Now to put a bit more floor down & earn some "ram testing" time.

tms9995
February 24th, 2010, 09:24 AM
It works!!! .... well almost, colour/vertical sync are a bit out of sorts on the UHF adapter. I haven't tried component video out yet. but I think we have a test-bed machine. Ran a sample basic program, fine.

Now to put a bit more floor down & earn some "ram testing" time.

Great news! The vertical sync issue may be due to a TMS9928 being fitted instead of a TMS9929. The 9928 has NTSC video timing while the 9929 is PAL. I had an old Fergusson TX9 TV and there was a simple resistor change to get it to sync up to the 30 frames/second.

andyp
February 24th, 2010, 10:23 AM
Stuart, I've had a quick check with the logic probe ( set to TTL/LS and PULSE ) and got the following results:
IC47 - CS2 = High initially, High when RESET held in and pulses for short duration when RESET released - Pulsing stops when RUN led goes out.
IC46 - CS2 = High initially, High when RESET held in and pulses for short duration when RESET released - Pulsing stops when RUN led goes out.
IC45 - CS2 = High initially, High when RESET held in and pulses for LONGER duration when RESET released - Pulsing stops when RUN led goes out.

ADDRESS LINES
The address line results can be divided into groups:
A1, A2, A3, A4, A6, A7
Without touching the reset button these are continually pulsing.(high, low and pulse lit)
With the reset button held in, these address lines are LOW and start pulsing when RESET is released and then remain pulsing.
A0, A5
Without touching the reset button these are showing LOW with the occasional pulse LED every 3- 4 seconds
With the reset button held in, these address line are LOW and start pulsing (high, low and pulse lit) when RESET is released, but only for the length of time that the RUN led is lit, then they return to their normal state of LOW with the occasional pulse LED every 3- 4 seconds.
The question is, have I got the correct settings on the logic probe ? ?

Nige - Great news about your Cortex - I could always try punishing mine by cutting its mains lead off !!

nige the hippy
February 24th, 2010, 11:24 AM
Great news! The vertical sync issue may be due to a TMS9928 being fitted instead of a TMS9929. The 9928 has NTSC video timing while the 9929 is PAL. I had an old Fergusson TX9 TV and there was a simple resistor change to get it to sync up to the 30 frames/second.
You know you might be right! my eyesight's gone terrible in the past 5 years or so! I'll take another look. If you're not right, That area of the motherboard is a little crustier than the rest.
However I've a microvitec cub, and a commodore 1084 monitor, It should be a case of making up adapter leads.
I can still try the other dram chips in to see if they're ok.

Stuart
February 24th, 2010, 12:33 PM
Great news! The vertical sync issue may be due to a TMS9928 being fitted instead of a TMS9929. The 9928 has NTSC video timing while the 9929 is PAL. I had an old Fergusson TX9 TV and there was a simple resistor change to get it to sync up to the 30 frames/second.
There are also two mods in the area of the sync separator circuit shown on the latest circuit diagram. This might be to improve the vertical sync?

Stuart
February 24th, 2010, 12:42 PM
Andy.

(Logic probe settings sound fine).

The EPROM chip selects sound fine - so that is another area of the circuit that seems to be working OK.

Looks like you probed the address lines on the RAMs (A0 - A7), rather than the EPROMs (A0 - A12)?

nige the hippy
February 24th, 2010, 01:19 PM
AAAAARRGGHH no component video out (in spite of the hole on the backplate) it looks like there were issues with the sync, as there are hand drawn mods on the circuit diagram. There's monochrome composite out from the chip, so all is not lost. but I think it's out with the 'scope tomorrow, and a good root around.

p.s Don't answer this one, Andy's problems need the attention.... incidentally it couldn't be a damaged eprom socket could it?

andyp
February 24th, 2010, 01:46 PM
Sorry Stuart - It's just me being a plonker again.

The info I gave you was for the Eprom pins A0 - A7 but I didn't spot A8 - A12 on the other side.
I'll have to give you the next thrilling instalment for A8 - A12 tomorrow.

Are my results what you would expect for the first 8 address lines?

Stuart
February 24th, 2010, 02:47 PM
They sound sort of OK! The activity when you release the reset button is good, but I'm not sure where this pulsing every 3-4 seconds is coming from.

When you release the reset button, the EPROM data is copied to RAM, so you should see activity on all the EPROM address lines for that 1 second. When the buzzer starts, the processor goes into a tight 'loop of death', so I would expect some lines to be static high, some static low, and a few pulsing. Not sure where the 3-4 second pulses are coming from - the processor shouldn't even be responding to interrupts.

Stuart
February 24th, 2010, 03:18 PM
it couldn't be a damaged eprom socket could it?

It's a possibility. IC47 is working well enough to at least read the reset vector from, and IC45 is working well enough to at least read the first part of the boot code.

Andy, can you pop the probe round all the address pins on *all* the EPROMs and check you have activity when you pop the reset button? Also check the *CS1 pin on each EPROM - should be pulsing even after the buzzer starts (I think). The PD pin on each should be static low. Check the power supply pins.

Nige - what might be a good way to check the data pins? Power off then check the resistance between the data pins on adjacent sockets?

nige the hippy
February 25th, 2010, 01:51 AM
Nige - what might be a good way to check the data pins? Power off then check the resistance between the data pins on adjacent sockets?
Sounds like a great idea, do a 3 way (ICs 45-46, 45-47, 46-47) continuity check on every pin.

andyp
February 25th, 2010, 09:45 AM
Stuart,
I've re-checked all the pins and listed the indications below. The random pulse I was seeing every 3-4 seconds on A0 + A5 seems to have disappeared - Maybe it was my probe randomly triggering. Also the data pulse on A11 seems slower or a different format to that seen on other address pins - If this means anything.

ADDRESS LINES
The address line results can be divided into groups:
A1, A2, A3, A4, A6, A7, A12
Without touching the reset button these are continually pulsing.(high, low and pulse lit)
With the reset button held in, these address lines are LOW and start pulsing when RESET is released and then remain pulsing.
A0, A5, A8, A9, A10, A11
Without touching the reset button these are showing LOW
With the reset button held in, these address line are LOW and start pulsing (high, low and pulse lit) when RESET is released, but only for the length of time that the RUN led is lit, then they return to their normal state of LOW. * (ON A11 THE DATA PULSE SEEMS TO BE SLOWER THAN THE OTHERS)

CS1 (x3) = Initially pulsing High / Low -- Reset button in = High --- Button released = Pulsing High / Low
CS2 / IC47 = High initially, High when RESET held in and pulses for short duration when RESET released - Pulsing stops when RUN led goes out.
CS2 / IC46 = High initially, High when RESET held in and pulses for short duration when RESET released - Pulsing stops when RUN led goes out.
CS2 / IC45 = High initially, High when RESET held in and pulses for LONGER duration when RESET released - Pulsing stops when RUN led goes out.

PD (x3) Continuous Low = Uneffected by reset
Voltage between pin 14 and pins 1/26/28 = 4.85v - All Eproms
Q1 to Q8 = Initially High -- Reset button in = High --- Button released = Pulsing High / Low for duration of RUN led then continually High.

I also had a quick check of :
Pins 11 to 18 of IC44 = Initially no indication on probe -- Reset button in = No indication -- When the Reset Button is released, these are active for duration of RUN led then back to no indication.
Pins 5,6,7,9,10,11,12,13 of all the RAM chips = Initially pulsing High / Low -- Reset button in = Low --- Button released = Pulsing High / Low (High LED brighter for duration of RUN led)

The continuity check between the Eprom pins was also all good.

Andy

Stuart
February 25th, 2010, 11:31 AM
Well you have seem to have activity on all the lines - nothing has failed to pull a line permanently high or low.

What I would suggest is that you now wait until Nige has laid a bit more flooring and has earnt (!) the time to test his spare set of RAMs and post these down to you. Try these with your Forth EPROMs. It is possible that Forth isn't working because you have a bad RAM chip, and Basic isn't working because of a dodgy EPROM checksum (I don't think the Basic code is actually reading anything from RAM up to the point where the buzzer starts, and so it wouldn't notice a bad RAM chip). Then perhaps your Basic EPROMs back to Nige to test in his Cortex. If your Basic EPROMs are proven good - then on to plan B - whatever that is!

Stuart.

andyp
February 25th, 2010, 03:31 PM
OK Stuart, Sounds like a plan !
Once again, thanks for all your time and effort, I didn't have a clue what to check.

Nige, I appreciate you rushing around and getting your Cortex up and running, but remember there's no rush, I can wait as long as you want.
It sounds like you've already got a list of jobs as long as your arm !

nige the hippy
February 27th, 2010, 10:54 AM
I haven't plugged the scope in, but I thought "what the hell..." so I've pulled one of the DRAMs Lo & behold it just sits there being dead with the "Basic" light lit, and the "Run" light glowing dully (does that sound familiar?). I popped one of the replacement Drams in, and it fires up fine, so they work in the machine as a valid substitute.
I can't test drams on my eprom programmer (it only does static ram), and I'm unwilling to do a lot of dram swapping on my cortex, so I'll pop 9 chips in the post in the hope that at least 8 will work. You probably only need one, so that gives you a set of 8 chips that will probably work to put in something else.
I suggest you swap them in one at a time so you know which one is faulty.
Of course, it could be something else!

Edit:- Just popped them in the post, but they probably won't go till monday morning now (there used to be a sunday collection from the box opposite :( )

Stuart
February 27th, 2010, 01:50 PM
it just sits there being dead with the "Basic" light lit, and the "Run" light glowing dully

Was the buzzer going as well Nige, out of interest?

Stuart.

nige the hippy
February 27th, 2010, 03:56 PM
Not sure, the buzzer seems a bit intermittent anyway (i.e. I haven't heard it definitely doing "anything")

andyp
February 28th, 2010, 01:40 PM
Fantastic news Nige, -- this could possibly be a glimmer of light at the end of the tunnel !!!

I'll look out for the delivery and keep you posted - Many Thanks

nige the hippy
February 28th, 2010, 02:23 PM
Quite likely an oncoming train! Don't get excited 'till it's fixed.

andyp
March 3rd, 2010, 07:56 AM
A positive update for a change!

Nige, I received your DRAM chips today and tried 8 of them together with the Forth Eproms. This gave me the Forth screen prompt and I actually ran a quick forth test routine for the first time in 20 years!
I then re-fiited the originals, one at a time and found to my suprise that 5 of my 4164s were faulty.
I then installed the new Basic Eproms and got the original problem with the same LED sequence and the continual tone.
So Stuart, it looks like you were spot on with your prediction.

I then dug out my original Basic eproms (Couldn't remember which one was faulty - Thought it was IC45) and tried different combinations of new and old eproms but stiil had the same fault.

But a great leap foward and my system is now working on Forth thanks to all of you.

So to the next step -

Where can I get some 4164s or MCM6665s or equivalents and where would be the best place to look - or Nige, can I buy 5 off you.

Also if I post the new basic eproms back to you together with my originals, would you mind testing them on your system for me.

One last question, the new Eproms were labelled

Cortex 1 EB84
Cortex 2 149E
Cortex 3 72EB

and I put them in sockets 47, 46, 45 respectively, as instructed but what are the hex digits, are they eprom checksums or do they refer to a memory map?

nige the hippy
March 3rd, 2010, 09:12 AM
Good news so far, it is a bit like pulling teeth though.
1) the 6665s were yours anyway, I had a fair size pot full, now (with a little shaking) I can fit them all into the same "racco drawer"
2) now I know my basic eproms work, I can get some known good images sorted.
3) I'm expecting some TMS2532s for myself through the post any day now, Provided they aren't counterfeit, I could blow another 3 basic roms (to the good images), test them, then send them down. Just send me back your spares when you've finished.
4) the hex numbers are checksums.

andyp
March 4th, 2010, 12:46 AM
Nige - Thanks very much for the RAM chips.
I'll send you my 3 eproms in the post today and then you can decide which ones to use.

Stuart
March 6th, 2010, 05:36 AM
This gave me the Forth screen prompt and I actually ran a quick forth test routine for the first time in 20 years!

Good news indeed. ;-)

Stuart.

nige the hippy
March 6th, 2010, 06:21 AM
Doh! 2532s aren't 2564s! so yes, good job you sent the basic eproms back.
Full of cold, but I've just had some "Lem-Sip", & will pop upstairs & have a go in a few minutes.

Stuart
March 24th, 2010, 03:50 PM
Doh! 2532s aren't 2564s! so yes, good job you sent the basic eproms back.
Full of cold, but I've just had some "Lem-Sip", & will pop upstairs & have a go in a few minutes.

Are you still with us Nige, or have you overdosed on the Lem-Sip? ;-)

nige the hippy
March 25th, 2010, 02:51 AM
Don't worry I am still with you. In order to test the eproms I can't get the safeblock in, which means I'm having to redo the mains bits, using components which are slightly buried. It's taking a bit longer than it should.

nige the hippy
March 31st, 2010, 10:58 AM
FINALLY! got the mains bits replaced on my cortex. I was a bit fed up that the hole in the back of the metalwork isn't exactly the right size for an IEC inlet so must be for a long-obsolete switch. I've put an IEC on it, and have to order a little latching push-button to go in the old mains lead hole. It's not too bad a codge, and I hate trailing mains leads.
I've just lifted the roms, slightly awkward, as there are caps and a case in the way. Checked them against Andy's and there's one byte completely wrong in IC47. Erased & reprogrammed.
Andy - I'll pop them in the post tonight, they should go first thing tomorrow morning, and if you're really lucky you'll get them before Easter.

Edit - the lack of vertical sync appears to be down to the TV! I've just tried it on my relic Philips Discoverer, and it's solid as a rock. (?...)

andyp
March 31st, 2010, 12:24 PM
Thanks Nige,

I'll let you know how I get on.
I've ordered some new electrolytics to replace the 30 year old capacitors in my power supply, so they should all arrive together.

nige the hippy
March 31st, 2010, 02:20 PM
Better add these to the whtech archive...

andyp
April 3rd, 2010, 05:26 AM
Nige, Received the Eproms this morning, plugged them in and **** SUCCESS *** a basic prompt appeared on the screen and no irritating tone from the speaker!
Thanks to all your hard work and patience, I now have a working Cortex.
Over the years it has come very close to ending up on the tip. I certainly would never have put money on it ever being coaxed back to life.
Also many thanks to Stuart for his fault finding tips and guidance.

Next stage, after replacing the electrolytics, is to load on the 2 games I have and then save them as WAV / MP3 so you can all have a copy.

nige the hippy
April 3rd, 2010, 05:34 AM
Hurray! one bad byte can spoil the barrel. (sorry O/T - apple related)

Is it supposed to beep on power up at all? mine doesn't - strange but I can't find the speaker/piezo at all on the diagrams.

andyp
April 3rd, 2010, 06:38 AM
Nige, I think the piezo is labelled as "BELL" on IC64 (Q6) - See ETI - Cortex part 2, Fig 1 (Circuit diagram for keyboard and control port)
On the board it's located 3 x IC sockets to the right of the +12 volt input lead.

nige the hippy
April 3rd, 2010, 07:05 AM
There's a slightly fried but nevertheless functional resistor attatched to the "piezo" terminals on mine. It's not there anywhere on the cct diags.
Other half of the question - does it beep on power up? (mine doesn't) it's a bit easier than trying to get it to beep in basic to ascertain functionality of the speaker.
It could be like the lack of sync problem I had - which turned out to be the fault of the TV, not the computer.

andyp
April 3rd, 2010, 07:44 AM
My Cortex doesn't beep at start up either but if you want to test the speaker press the "rub out" key. If you haven't entered any text it will beep each time you press it.
On mine the two piezo circuit board contacts are for the leads to the piezo, the only resistor is to the right of these contacts. = R45

tms9995
April 3rd, 2010, 07:55 AM
Nige/Andy,

I got all warm and fuzzy inside knowing that, out of this, not one but two Cortex's have been brought back to life and we got a copy of Forth as well! Great work to all involved.

nige the hippy
April 3rd, 2010, 09:23 AM
not saying too much yet.... but mine went totally unstable, I got to test the speaker (continuous beep:() I've done some reseating, and it now seems ok. But I'm keeping my fingers crossed until it boots 50 times on the run & from cold too.
I'm hoping it isn't something funny like an earthing problem, Ive put all the screws in that it looks like it should have.
I'm waiting for an order to turn up, hopefully with the mains switch in. then I can put it together properly again.

Ksarul
April 3rd, 2010, 03:55 PM
I'll try and get the updated ROM images up on WHTech sometime this week. I've been pretty busy at school this month, so I've been totally quiet otherwise. . .

Stuart
April 6th, 2010, 02:14 PM
Excellent news Andy!

Stuart.

andyp
April 8th, 2010, 07:20 AM
Nige, A quick correction to my earlier post, the speaker is shown on "fig 2 Circuit Diagram of the RS232 and cassette interfaces".

I'm currently having fun and games trying to recover my Cortex programs from the old cassette tapes.
After trying several cassette players and having the dreaded mains hum and frequency equalisation destroying the waveforms, I have now found an old dictaphone (battery operated). This basic player seems to have just the bare minimum of amplifiers to replay rather than destroy the original info.
When I've got them into WAV format, I'll post them on the forum.

nige the hippy
April 8th, 2010, 08:31 AM
AAAAHH! Kind of pencilled in as an afterthought!

Mine seems to be stable & nice now. I've put a good little mains switch on the back & screwed it mostly together. I was just on the point of putting the top on when I noticed the frayed disk connector, so it's another hunt in the shed for another, or buy a spare 34 way idc connector & splice it on the good side of the fray.

andyp
April 9th, 2010, 02:39 AM
A quick question to all of you using a Cortex with an old analogue TV.
Is your screen display to far to the left?
I am unable to see the very first character on the left hand side of the screen and my TV doesn't have the luxury of a manual adjust.
How do you think I can overcome this - Is it likely to be a circuit problem or a modulator problem - Any ideas?
It's not terribly important, but it is annoying - I've tried several different TVs and the're all the same.

Stuart
April 9th, 2010, 01:06 PM
Might one of the TVs have an internal adjustment pot on the PCB? If you have a friendly local traditional TV repair shop they might be able to advise.

(Usual disclaimers about electrocuting yourself apply)


A quick question to all of you using a Cortex with an old analogue TV.
Is your screen display to far to the left?
I am unable to see the very first character on the left hand side of the screen and my TV doesn't have the luxury of a manual adjust.
How do you think I can overcome this - Is it likely to be a circuit problem or a modulator problem - Any ideas?
It's not terribly important, but it is annoying - I've tried several different TVs and the're all the same.

nige the hippy
April 9th, 2010, 03:14 PM
Now that's strange.... I put it down to the TV, but perhaps it isn't. There's also a little visible flyback line diagonal top right hand side. I wonder if it was a bug.

Stuart
April 10th, 2010, 01:29 AM
There's also a little visible flyback line diagonal top right hand side. I wonder if it was a bug.

Tried tweaking pot R37 on the video output stage?

nige the hippy
April 10th, 2010, 05:18 AM
That was the first thing I did. it seems to adjust mostly the contrast, and finally the sync gives up. (although I'll re-ascertain that)

andyp
April 11th, 2010, 05:15 AM
I've now got all the WAV files prepared and ready to put on to the forum.
Can anyone advise me how to go about this. I've made an attempt to upload them but it appears that there is a size limit.
When zipped, the largest file is almost 72 Meg.

Ksarul
April 11th, 2010, 05:55 AM
Anytime I've had to transfer files that large I had to use something like Rapidshare as a way point for the sender (or an FTP site like WHTech when I send them back out, which is why I've put everything up there to keep it available to everyone).

andyp
April 11th, 2010, 06:28 AM
Should I e-mail them to you for inclusion on WTECH or are they too large to add as attachments ?

Ksarul
April 11th, 2010, 06:48 AM
My e-mail (most of e-mail providers in existence, for that matter) won't accept file attachments larger than 10MB, Andy. You can use the LiveDrive function on your Hotmail account to put files up to 50MB up and share them with specific individuals for transfer, but that doesn't help with the largest ones. Pretty much the only options left are mail or Rapidshare for files that size.

Ksarul
April 11th, 2010, 06:50 AM
One other thought: a Yahoo group! They have a file storage area. Maybe we should start a Cortex group on Yahoo for data transfers. There are likely enough of us now to make it useful. Thoughts?

nige the hippy
April 11th, 2010, 08:26 AM
That's a bit huge, are they recorded at 44Ksamples per second, 16 bit stereo? in which case, you could archive the original recordings to CD and possibly reduce it to 10 -11 ksps, 8 bit mono & still get away with it. Good in some ways to record the original as accurately as possible, as it increases the chances of getting the original data back should the tape be bad, but as far as getting a useable copy....
If you haven't got a sound editing program that'll do it send us a CD & I'll plug it into sound forge (& keep a copy too!)

andyp
April 11th, 2010, 01:09 PM
Rather than making copies of the original tapes, I loaded them onto my Cortex and then saved them back into Audacity to get perfect copies.
I now realise that I left the sample settings at default which is a bit of overkill.
I'll have another play in the next few days and try to get working copies small enough to e-mail.

nige the hippy
April 11th, 2010, 02:41 PM
I was meaning load the WAVs into e.g. Audacity & downsample it from there, rather than going through the rigmarole of re-recording it.

andyp
April 12th, 2010, 08:49 AM
I've re-sampled the Cortex game files in WAV format and they are now all less than 10 meg.

I went through all my old tapes and have managed to find the following:

MAZE (Instructions on screen)

SPACEBUGS (Instructions on screen)

BURGLAR
Instructions = Move the burglar around the screen collecting the five keys and then take them to the bank to open the safe.
Each key scores 100 points and there is a time bonus on each sheet. "L" to jump, "<" left, ">" right, SHIFT + "<" left jump and SHIFT + ">" for right jump.

ARCHIE (Instructions on screen)

SKI-RUN (Instructions on screen)

ALIENS (Instructions on screen)

Use the LOAD command plus the names shown above.

Maze, Spacebugs, Burglar and Archie all appeared for sale in the newsletters - (I think Spacebugs might have been originally called invaders)

Archie was my one and only attempt at writing a multi-screen game and I have been told by my kids that it is very frustrating compared with modern games.
Because I spent so many hours testing it, I must have become quite an expert and tweeked it so that it wasn't too easy.
As a result, it is very unforgiving, will not let you step of the ladders before reaching the ground etc and you have to get used to timing your jumps. - Apologies
(You could always alter the program to increase your chances)

"ALIENS" and "SKI-RUN" were my early experiments and a bit basic but I have included them anyway.

This afternoon, I e-mailed them all to Ksarul / WHTech.

Nige - Do you want me to e-mail them to you ( 2 x 10 meg emails + 1 x 5 meg email) or do you want to wait and get them from WHTech?

nige the hippy
April 12th, 2010, 12:35 PM
Nige - Do you want me to e-mail them to you ( 2 x 10 meg emails + 1 x 5 meg email) or do you want to wait and get them from WHTech?
Thanks Andy, but don't worry, I'm fine downloading them from WHTech.

davidloudfoot
May 31st, 2010, 04:13 PM
HI,

I have a cortex that I built in the 1980's.

Its been in the loft for 20 years and I have often thought about trying to get it working.

any help or encouragement would be great.

it has the later Maplin display board and 256k of ram with the ls2001 replacement header and the eproms were reprogrammed for the later disk drive chip ( changed them to a 2764 on a header board)

I do hope to hear from someone that has a working machine.

nige the hippy
June 1st, 2010, 02:02 AM
You've probably got the most advanced machine of all of us. Me, & AndyP have working machines in the UK (although we both seem to have slight sync problems in that the leftmost side of the display is a bit hidden) I have a floppy on mine, but the cable's damaged & I'm waiting till I have a few bits to order before getting a (few) replacement IDC sockets. Have a look back through the thread.
I'd be inclined to test the PSU separately (with a dummy load (car bulb or something)) before connecting to the logic board, also do a shorts test on the power conections to the main board. Usual faults for a machine that hasn't been powered up for 20+ years are dried out power supply electrolytics (ripply outputs & occasionally a minor explosion), Tantalum capacitors on the PCBs shorted out (shorts the power supply & can burn tracks off the pcb, sometimes there's one on the reset, which stops the machine resetting), oxidised I/C sockets (cured by removing & reseating chips), damaged memory (caused by cosmic rays!), and dirty/oxidised keyboard contacts.
We'd love a dump of the roms, & if these quick notes go over your head, we're happy to help further!

davidloudfoot
June 1st, 2010, 02:17 PM
right then....all i need to do is get the workshop sorted out and explain that I am hiding in the loft trying to ressurect a machine hedden there for 20 years of marriage...should be easy !

seriously I will try to test the PSU and check out the machine, last I tried it just sat there but the voltages were fine, might head for the reset switch and see if the cap has gone short ! probably be a few weeks beofre I get a chance but great to hear that I do not have the last one.

nige the hippy
June 2nd, 2010, 02:50 AM
There are links above to the whtech archive which has software, schematics & reprints of the original ETI articles etc. I can't be bothered going back through 23 pages though!
I've done a proper loft conversion now, there's no way that the CDC 14" disk drives would go up a ladder, I was worried about the stairs with 2 blokes and over a hundredweight of drive between us. Next house has to have a semi-basement, so I can get to use the (about 1/4 ton of) band-printer.

Ksarul
June 2nd, 2010, 06:09 PM
Excellent! We seem to have found another Cortex user :) Welcome!

I've been pretty busy of late, but I will try to get the games Andy sent me up onto WHT this weekend.

davidloudfoot
June 6th, 2010, 07:34 AM
when I first built mine it had the display too far to the left...

are you on a RGB set up or the modulator ?

nige the hippy
June 6th, 2010, 09:50 AM
Mine hasn't got a composite/rgb output (it has a hole in the case for a din socket, but nowhere on the board (or the schematic even!)for it to connect to) purely a modulated output.
you say "when you first built it the display was too far to the left", did you correct this? it looks like it could be firmware correctable.

davidloudfoot
June 6th, 2010, 02:42 PM
It's a long time ago but I remember taking the video connection from the input of the modulator and using this for composite to a TV...I think I used a couple of transistor stages to buffer it and drive it.

Some where i thnk i have the user group news letter with the "official" RGB interface and maybe even a copper diagram for the board...Will have a look next weekend.

Stuart
November 21st, 2010, 04:15 AM
Anyone still here? ;-)

Stumbled across this: the display being too far to the left - a design fault with the European VDP it seems. See:

<http://spatula-city.org/~im14u2c/vdp-99xx/e3/1982_TI_Europe_Proposal_for_9929A_Improvements_(in c._External_Video).pdf>

Section 3.1, para 2, on page 6 of the PDF.

(Many of the docs at <http://spatula-city.org/~im14u2c/vdp-99xx/> make interesting reading.

Stuart.

Stuart
November 21st, 2010, 04:19 AM
In the above link, remove the space near the end between "(in" and "c._External".

Stuart.

nige the hippy
November 21st, 2010, 02:31 PM
We are still alive, just even more busy than before.
very interesting - so there's nothing to be done except attack the chip with a dremel & an ion beam!
Thanks stuart.

Ksarul
November 22nd, 2010, 09:17 AM
I have been gifted with a nearly-complete copy of the preliminary data sheet for the 74LS2001 which I am in the midst of turning into a fully-functional document (much like I did for the Forth and BASIC manuals). There will be a few missing words here and there as the copy I received was missing a narrow strip at the end of each line of text. Sometimes it is easy to reconstruct a line, but there are instances where there is no clue as to what the missing text was.

One major advantage: the timing diagrams and the pin out are complete, so with what we already knew and the contents of this document, it should be possible to code a replacement for it.

spelc
December 6th, 2010, 10:45 AM
TMS9995, one of your earlier comments reminded me of something I haven't thought of in ages. Marinchip Systems also built a TMS9900 board for the S-100 bus. I was looking for one of those for a long time but never did encounter anyone who'd ever heard of it or them. Thanks for the reminder. . .one more vintage 9900-family system for me to track down. :)

I have a Marinchip M9900 S100 box - It's a huge Integrand chassis with M9900, 64k/128k RAM and two DS/DD 8 inch floppies. There's even the original manual somewhere. There are boxes and boxes of floppies for it. This is the machine used for the port of MDEX to the Powertran Cortex. There's also a Cortex and a Scandinavian industrial version of the Cortex. MDEX's big brother NOS was ported to this as far as I remember.

These machines all worked when last powered up. If someone wants them - just ask.

Stephen

tms9995
December 6th, 2010, 12:53 PM
I have a Marinchip M9900 S100 box - It's a huge Integrand chassis with M9900, 64k/128k RAM and two DS/DD 8 inch floppies. There's even the original manual somewhere. There are boxes and boxes of floppies for it. This is the machine used for the port of MDEX to the Powertran Cortex. There's also a Cortex and a Scandinavian industrial version of the Cortex. MDEX's big brother NOS was ported to this as far as I remember.

These machines all worked when last powered up. If someone wants them - just ask.

Stephen

Er yes, I'd love to get my hands on that gear! I believe I remember you (along with Richard Roberts) from MPE?

Stuart
December 6th, 2010, 04:23 PM
I'd love the Cortex ... and live in Southampton. ;-)

Stuart.

tms9995
December 7th, 2010, 07:31 AM
I'd love the Cortex ... and live in Southampton. ;-)

Stuart.

Fine by me. I have two already :) More interested in the other stuff. If I find it doesn't have a lot more to contribute to the Cortex 'preservation project', I'll give it to Ksarul since he has a real TI fetish...

I'm hoping to have some news regarding building the Cortex ROM from source very soon...

Stuart
December 7th, 2010, 08:43 AM
Fine by me. I have two already :) More interested in the other stuff. If I find it doesn't have a lot more to contribute to the Cortex 'preservation project', I'll give it to Ksarul since he has a real TI fetish...


I'll take the 'industrial' Cortex as well if there are no other takers. I know another chap in the UK who will probably bite my arm off to get it and put it to good use.

Stuart.

tms9995
December 7th, 2010, 08:47 AM
:cry:

nige the hippy
December 7th, 2010, 08:55 AM
I have a Marinchip M9900 S100 box

I'm running seriously short on space but..... Wasn't that the original Autocad machine? If Ksarul can't take it, and you're not TOO far away, and you want it gone, then can you put me on the list please!

Stuart
December 7th, 2010, 10:04 AM
I'm hoping to have some news regarding building the Cortex ROM from source very soon...

If you're rebuilding the code, what do you make of this? VDPDSR module, page 10, last line in the 'TEXT MODE' block - JHE FTMODE. Shouldn't that be a JL REMCUR jump (to the following block) followed by a BLWP @FTMODE since FTMODE comprises a WP pointer and PC pointer? [I'm working on porting the code across to my TM990 9900-based system so have been looking quite closely at it.]

Stuart.

(tms9995 - also sent you a PM)

tms9995
December 7th, 2010, 11:05 AM
If you're rebuilding the code, what do you make of this? VDPDSR module, page 10, last line in the 'TEXT MODE' block - JHE FTMODE. Shouldn't that be a JL REMCUR jump (to the following block) followed by a BLWP @FTMODE since FTMODE comprises a WP pointer and PC pointer? [I'm working on porting the code across to my TM990 9900-based system so have been looking quite closely at it.]

Stuart.

(tms9995 - also sent you a PM)


Don't see a PM...

The code in the pdf listing is what's running in the Cortex. I'm not sure what you point out is right or wrong without looking at it in detail although, if it was a JL REMCUR, it would be pointless as the next instruction executed would be the one located at REMCUR whether it made the jump or not. The sources I have reconstructed are based on some files I found on an old disk a while back. They were not up to date and I had to create some from scratch! I modified them to match the PDF. After assembling each module, I then do a binary compare of the linker output with an image of the original ROM to confirm the source produces the correct code.

I also have recovered a bunch of MDEX disk images. These include QBASIC, SPL, Pascal and Forth compilers and also the full-screen text editor Window. I will put all this together with the latest emulator when I can.

I plan on producing a couple of utilities that provide for disk formatting and disk image creation on the Cortex. These would be down-loaded from a PC to the Cortex via RS232 comms.

I'm doing my best...

tms9995
December 7th, 2010, 01:02 PM
I'm running seriously short on space but..... Wasn't that the original Autocad machine? If Ksarul can't take it, and you're not TOO far away, and you want it gone, then can you put me on the list please!

Check out the history of Autocad on John Walker's site:

http://www.fourmilab.ch/autofile/afpdf.zip

Do a search for M9900, QBASIC, MDEX, Marinichip etc.

spelc
December 8th, 2010, 03:08 AM
[QUOTE=Stuart;160491] [I'm working on porting the code across to my TM990 9900-based system so have been looking quite closely at it.]

TM990? If this is T-bus stuff, there's probably a collection of T-bus boards and 99xx chips at Hill Lane. We even built a few 99000 boards at one time.

Stephen

Stuart
December 8th, 2010, 04:17 AM
[QUOTE=Stuart;160491] [I'm working on porting the code across to my TM990 9900-based system so have been looking quite closely at it.]

TM990? If this is T-bus stuff, there's probably a collection of T-bus boards and 99xx chips at Hill Lane. We even built a few 99000 boards at one time.

Stephen

Yes, its the T-bus stuff. Can I just come over and rummage through all your cupboards? ;-) ;-)


If you sort out what you're happy to get rid of, I'm more than happy to come and collect. ;-)

Stuart.

Ksarul
January 2nd, 2011, 07:38 AM
As I finally got a chance to drop in here after a long forced absence--I am definitely interested in the Marinchip machine, as I've been looking for one of those for a long time! Didn't MPE also make the hard disk interface for the Cortex? One of those would be a very interesting find as well.

Stuart
January 5th, 2011, 02:02 PM
In the VDP section of the Cortex circuit diagram + technical description document, there are two graphic screenshots which I assume were drawn in BASIC using the Cortex. Does anyone by chance have the BASIC listing to produce these? (They're not in the Cortex user guide - I've looked there already!)

Thanks,
Stuart.

Ksarul
January 12th, 2011, 03:59 AM
Unfortunately, I don't have the BASIC listings, Stuart. I have almost finished doing a complete restoration of the 74LS2001 manual though. I have two small diagrams to recreate and then I will upload it to WHTech--with luck, this weekend. The copy I had was missing a small bit at the end of each line on a lot of pages, but I was able to deduce the correct text for all but two lines--not bad for a 24-page manual, especially since both of them were in the chip's introductory blurb, so the meat of the document is complete.

Stuart
January 25th, 2011, 03:53 PM
Going through the Basic source code I've come across an undocumented Basic command - SWAP - which does a screen colour substitution in GRAPH mode.

To use it, first there is a bug in one of the jumps in the code that needs to be corrected:

MWD(3390H)=1308H (the original value should be >13EF)

You then need to set up the colour substitution table. This is stored in the 16 bytes from >00A4 to >00B3. Initially these contain the values >00 to >0F. What the command does is go through the screen colour table and if a pixel currently has the colour code 0 then it replaces that with the colour specified by the colour code in the first byte of the table. If the current colour code is 1 then it replaces that with the colour specified by the colour code in the second byte of the table, and so on. The colour codes are as specified on page 4-77 of the user guide.

So as an example, the following should work:

10 MWD(3390H)=1308H (correct the bug in the code)
20 MEM(00A8H)=2 (change everything thats dark blue to medium green)
30 MEM(00ABH)=6 (change everything thats cyan to dark red)
40 GRAPH (graph mode, default is dark blue text on cyan)
50 PRINT "HELLO WORLD" (print some text)
60 WAIT 100 (delay 1 second)
70 SWAP (swap colours in screen colour table)

BillEaves
March 11th, 2011, 03:58 AM
Anyone else on the forum have a Cortex? I just got one and I don't have a lot of information on it yet..




I used to have one I built in the early 80s. Unfortunately after many years of it sitting in my damp garage it got so rusted I ended up throwing it away :-(

It was a superb machine for its day, sadly not a lot of software for it. A situation I find myself in now with my Amiga systems.

If any of you have the game CBlocks, a tetris clone for the Cortex, it was me that wrote it BTW !

I do still somewhere have all my manuals, plus designs for an Eprom programmer I made for the E-bus.

Going to using hard drive based machines seemed a bit of a backward step after I was used to everything being loaded in from Eproms on my Cortex.

Great to here there are people still using the Cortex and actually have heard of them. When I searched the net a few years ago no links came up for Powertran Cortex.

Brings back memories, the Cortex was my pride and joy for many years.


Bill.


PS. I should also have all the Cortex User Group newsletters still around somewhere.

tms9995
March 12th, 2011, 07:09 PM
Hi Bill,

Welcome to our Cortex Forum!

Glad we could stir up some fond memories. Anything you can add to our documentation collection would be greatly appreciated. We are missing one or two Newsletters, so please take a look at the Whtech FTP site and see if you have the missing ones (or anything else you have and we don't!).

Thanks!