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View Full Version : Any UK based S100 users out there ?



zippysticks
November 26th, 2017, 01:21 PM
Folks,

Having just acquired a Northstar Horizon (doesn't seem to boot from floppy) I wondered if there are any UK based users out there - particularly if you based in the South East. Could do with some help getting mine to work and sourcing interesting s100 boards.

Thanks in advance.

Moonferret
November 26th, 2017, 03:48 PM
Ahh, was that the one that sold on Ebay last week? Was tempted by that one myself. I've a couple of S100 systems that I'm currently trying to revive along with a Northstar Horizon that belongs to a friend.

Are you getting any activity from your system? Does it try to boot from disk?

Cheers,
Dave

amouse
November 27th, 2017, 01:37 AM
Hello from Marcus in Wixford.

So I am now based in UK Midlands, at least it is now the same country [as you]. I can't offer much more than solidarity and to say you should post pics of what is and is not working and the config etc. Hard sectored disk controller and media , I ask ??

mb

daver2
November 27th, 2017, 02:38 AM
Another one here - in Worcester though.

Post pictures and details of problems and we will try and walk you through getting it working...

BTW. Welcome to the UK Marcus...

Dave

zippysticks
November 27th, 2017, 02:54 AM
Ahh, was that the one that sold on Ebay last week? Was tempted by that one myself. I've a couple of S100 systems that I'm currently trying to revive along with a Northstar Horizon that belongs to a friend.

Are you getting any activity from your system? Does it try to boot from disk?

Cheers,
Dave

That was the one - the chap had a veritable Aladdin's cave of vintage computers and I bough just about half of everything he had including the Northstar.

Anyway in regard to the Northstar it appears to have three boards - the Z80 processor (no monitor option fitted), 64K RSM card and the floppy controller card. Has three floppies fitted labelled A, B and C - one full height and two half height drives (models TBC as I have not removed them yet).
I have connected my laptop and terminal program to the right serial port (null model cable via USB serial connector) and powered on. Serial settings at 9600, 8,N,1 as the unit has been fitted with a switch on rear that selects either 300 or 9600 baud.

I get a single 0 character on the screen and nothing else. The unit tries to access drive A - drive light comes on and head appears to move back and forth every few seconds with (what I can only describe as) a scraping sound - not something that worries me as it doesn't sound unusual for an old 5 1/4 inch floppy drive - based on my Commodore experience.

I have a folder full of original floppies that came with the unit abut none of the three I have tried appear to help the machine boot.

In the limited time I have with it so far I have tried:
1. Removing all but the CPU card to see if anything changes on the terminal - although probably futile without a monitor ROM installed on CPU board.
2. Removing each card and reseating all the socketed IC's.
3. Removing the cable from the edge connector of drive A (all three connected in series) to see if it would boot from drive B but it doesn't try to access B and I don't understand the drive addressing yet mechanism yet so may be wasting my time there.

Any pointers ?

zippysticks
November 27th, 2017, 02:59 AM
Thanks Dave.

Not much to go on yet until I start dismantling but here are the the first few pictures showing the front, rear and top off.
Will pull the drives out this evening and get some snaps with details of the drive types.

42131
42132
42133

acollins22
November 27th, 2017, 10:05 AM
Hello zippysticks,

I was an S-100 owner 30 years ago and hope to be again soon. There were a few interesting S-100 system on ebay here last week but all got a bit too rich for me.

Hopefully you'll get everything sorted. Please keep us informed.


Cheers,

Andy.

daver2
November 27th, 2017, 10:21 AM
Andy,

Did you get your NASCOM fixed (whilst I am in NASCOM mode)?

Dave

acollins22
November 27th, 2017, 11:50 AM
No Dave, not yet :-( I would very much like to though.

Andy.

daver2
November 27th, 2017, 12:17 PM
Not too interested in the drives at this stage...

More interested in what the cards are and how they are configured.

Make a note of exactly which card came out of which slot and how the links/switches are all configured - ditto for the 'main board' (switch/link settings that is). This will be extremely useful to you later on. Buy a hard backed notebook and make lots of notes. You will be amazed how many times you will come back to the notes you make. Take lots of photographs as well. I have a camera purely for old computer photographs!

Do NOT apply power - resist the temptation!!!

I too was looking at that machine - but I have enough projects here at the moment and the thought of informing my wife that I had a new machine to fix... No Dave don't go there!

Andy: do you want to create a thread on the forum for your NASCOM project and you can tell me where you have got to (or have I missed it). I see various posts all over the place, but can't piece them together at the moment. I see you have a video display - but you seem unsure as to what the CPU is up to and why you can't get a sensible video picture I guess?

Dave

zippysticks
November 27th, 2017, 12:31 PM
That was the one - the chap had a veritable Aladdin's cave of vintage computers and I bough just about half of everything he had including the Northstar.

Anyway in regard to the Northstar it appears to have three boards - the Z80 processor (no monitor option fitted), 64K RSM card and the floppy controller card. Has three floppies fitted labelled A, B and C - one full height and two half height drives (models TBC as I have not removed them yet).
I have connected my laptop and terminal program to the right serial port (null model cable via USB serial connector) and powered on. Serial settings at 9600, 8,N,1 as the unit has been fitted with a switch on rear that selects either 300 or 9600 baud.

I get a single 0 character on the screen and nothing else. The unit tries to access drive A - drive light comes on and head appears to move back and forth every few seconds with (what I can only describe as) a scraping sound - not something that worries me as it doesn't sound unusual for an old 5 1/4 inch floppy drive - based on my Commodore experience.

I have a folder full of original floppies that came with the unit abut none of the three I have tried appear to help the machine boot.

In the limited time I have with it so far I have tried:
1. Removing all but the CPU card to see if anything changes on the terminal - although probably futile without a monitor ROM installed on CPU board.
2. Removing each card and reseating all the socketed IC's.
3. Removing the cable from the edge connector of drive A (all three connected in series) to see if it would boot from drive B but it doesn't try to access B and I don't understand the drive addressing yet mechanism yet so may be wasting my time there.

Any pointers ?

Gah - this babysitting moderator post approval delay is killing me.

Well I took the drives out of the machine to photograph and inspect and when replaced I also reseated the three cards again - the Northstar burst into life !
Have tested all three floppy drives and they all seem to read fine.

So I'm a happy chap.
Not much for me to do to this machine other than polish the wooden case and find a mechanism of building new sets of floppies from the disk disk images I want to download. If anyone has any idiots guides to transferring images from PC to Northstar then I'm all ears.

Guess I better focus my attention back on the Gemini GM925 I got form the same chap - its an 80bus machine with proprietary serial keyboard (6 pin DIN) and strange composite video output that I can't seem to get anything from. Will see if there is an 80bus forum and ask there.

zippysticks
November 27th, 2017, 12:39 PM
Hi Dave - see my earlier (moderator delayed) post.
The machine has sprung into life after a reseat of the drives and cards.
Card photographs here though as I took pictures while dismantling.

42138
42139
42140
42141

Moonferret
November 27th, 2017, 12:47 PM
I get a single 0 character on the screen and nothing else. The unit tries to access drive A - drive light comes on and head appears to move back and forth every few seconds with (what I can only describe as) a scraping sound - not something that worries me as it doesn't sound unusual for an old 5 1/4 inch floppy drive

As daver2 has already said, make a note of the dip switch settings before working on the machine. It's always a good idea to take a photo of each board as it was when you got it so you can always refer back to it if you need to later on.

Do you know which drive controller is fitted? There were two main ones. The MDS is the earlier single density controller whereas the later double density one is the MDC models. Check you are not trying to boot DD media on an SD controller. I've done this before :)

Also, remember that there will be no serial output until the machine has booted N*DOS or CP/M. The only boot ROM is on the drive controller (About 512 bytes)

The Horizon I'm working on at the moment is pretty much at the same stage as yours. Powers on, head seeks backwards & forwards about a dozen times before the drive stops. It's taken a while to get to this point due to faults on the CPU & RAM boards. I have found using a ROM board with a monitor program a lifesaver so far.

Anyway, still learning myself here but happy to help where possible. Plenty of other very knowledgeable folk on here :)

zippysticks
November 27th, 2017, 01:18 PM
Hi Dave - like your comment about what your wife would think ...

You should have seen the look on my wifes face when I trundled through the door three times with the Northstar, Superbrain and Gemini GM925.

Usually I take them through the garage at the side of the house to my 'man cave' at the bottom of the garden.

daver2
November 27th, 2017, 01:21 PM
I can see from the (delayed...) posts that your address links for the bootstrap on the CPU card are set to E8xx.

The 256 byte PROM BOOT is on the disk controller as moonferret has stated and (if the disk drive is making its usual sound) then the CPU and disk controller are trying to do something.

Have you the manual set for the system and cards you have? If not, I could point you in the right direction for them.

EDIT: Why don't I just post a link to the ones I have just found? They may not be the correct ones for your particular cards though... http://www.s100computers.com/Hardware%20Manuals/Northstar/NorthStar%20MDS%20manual.pdf and http://www.hartetechnologies.com/manuals/Northstar/North%20Star%20ZPB-A%20Processor%20Manual.pdf.

Somewhere I have a disassembly of the disk controllers boot ROM. I did an emulator for a N* many years ago - so all this information is flooding back...

Dave

zippysticks
November 27th, 2017, 01:38 PM
The machine came in it original box with all the original manuals for the cards and a folder containing around 30 disks including the original Northstar disks.

Really pleased it all seems to be working - I can spend some time reading the manuals and figuring out HOW it all works.

Thanks for the links - those are useful resources.

42142

Moonferret
November 27th, 2017, 01:41 PM
42141

Just a heads up, this looks to be a modified 32k board. Originally, it would have originally been fitted with 4108 (8192x1 DRAM) chips. I believe this was quite an easy modification and replaced the 4108's with more common 4116 chips.

lutiana
November 27th, 2017, 01:49 PM
Gah - this babysitting moderator post approval delay is killing me.


It's killing the SPAM on here as well.

daver2
November 27th, 2017, 01:57 PM
Don't knock it - the moderators are doing an excellent job of keeping the SPAM away. It is just a minor inconvenience for new posters - you will thank them though in the long run. I see you are past the moderation level now - so you should be 'good to go'!

I have found my N* emulator source code. I don't know what has happened to my disassembly of the disk boot PROM (but I can recreate it again fairly quickly if we need to). I did find my part disassembled HDOS code though...

Dave

daver2
November 27th, 2017, 02:00 PM
Looks like you are away now!

You should have seen the look on my wife's face when I came back with a PDP-11/45 :-)!!!

Dave

Moonferret
November 27th, 2017, 02:49 PM
Really pleased it all seems to be working - I can spend some time reading the manuals and figuring out HOW it all works.

Fantastic! Congrats on getting it working :)

I have to admit, the delayed posts confused the hell out of me on this thread.

Cheers,
Dave

alan8086
December 30th, 2017, 08:27 AM
Just to answer the original question, I am UK based and have an S100 system - an IMS 8000 (industrial Micro Systems) Two 8" Shugart floppy drives, Linear power supply and 12 slot S100 board. Its the basic setup with the I/O card, CPU card, floppy controller card and 4 16K RAM boards. It came with CP/M 2.2 and quite a lot of software - I've recently got my NEC APC 8" drives hooked up to a Pentium PC via and FDADP adapter so I can back up the software disks it came with - With the APC drives, I can even read some disks that the IMS 8000 could not seem to read such as my copy of TLO (The Last One)

Only trouble is, the IMS 8000 developed a fault a while ago - It no longer seeks the boot disk when you turn it on - I'll get round to fixing it one day!

jimwatt
February 13th, 2018, 06:09 AM
Folks,

Having just acquired a Northstar Horizon (doesn't seem to boot from floppy) I wondered if there are any UK based users out there - particularly if you based in the South East. Could do with some help getting mine to work and sourcing interesting s100 boards.


Not in the UK but I do know a lot about Horizons and currently rebuilding one, which is going well.

On power up a disk led should light up.

On several of my boards the tantalum capacitor on the nominal +16v rail - which may be +22v blew
on some memory boards the cap after the -12v reg was shorting.

The monitor EPROM was not normally fitted.

Check PSU voltages on the big caps and examine the tantalum caps on the boards

A CPU, HRAM card and FDC is the normal basic configuration.

The disks are addressed normally with drive select jumpers and the last one in the chain has a terminating resistor pack. The FdC allows for four drives. Drive 0 boots.

see: www.connect.gi/northstar.htm

zippysticks
February 16th, 2018, 04:34 AM
Great to read about your progress. I might have been a bit luckier getting mine going with minimal effort but lots of great tips in your text regarding things to watch out for.

ef1j91
February 16th, 2018, 07:37 AM
Just to answer the original question, I am UK based and have an S100 system - an IMS 8000 (industrial Micro Systems) Two 8" Shugart floppy drives, Linear power supply and 12 slot S100 board. Its the basic setup with the I/O card, CPU card, floppy controller card and 4 16K RAM boards. It came with CP/M 2.2 and quite a lot of software - I've recently got my NEC APC 8" drives hooked up to a Pentium PC via and FDADP adapter so I can back up the software disks it came with - With the APC drives, I can even read some disks that the IMS 8000 could not seem to read such as my copy of TLO (The Last One)


Getting off-topic a bit here, but I was just floored to learn that IMS "still exists" to this day[1]. It seems to be one of the exceptions of early microcomputer companies of the 70's lasting beyond 3-5 years or the eventual PC onslaught.

Anyway, happy S-100-ing!

[1] http://www.s100computers.com/Hardware%20Folder/IMS/History/History.htm

jimwatt
February 17th, 2018, 06:56 AM
Pleased to see a bit of replugging got things going, IBM S/34's were like that.

I failed to point out you can get a lot of information from the parity LED on the ram card.

It should light up on power applied an then goes out when a disk boots. If it does not light up
the memory card i duff.

I can't recall any CPU faults, but memory and the disk controller account for most problems
after the drives. As someone mentioned the CPU is set to jump to E800 which is the default
address of the memory mapped FDC.

Good luck.

jimwatt
March 3rd, 2018, 01:29 AM
Yes it does look like that. I upgraded a number of 32K boards to 56K - Although the board may have originally been designed for 4108's NorthStar seem to have bought up a batch of 4116's with either a high or low bit fault and the boards we had were populated accordingly with graded chips. I paid a company called 'Hotel Micro Systems' based in the UK 40 for the details of the mod which was replace all the chips with new good 4116's which had fallen in price, and add some diodes for address selection leaving a hole for the memory mapped FDC. The mod worked very well and saved a lot of money. I upgraded around eight boards and expect they did more in the UK.