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tezza
December 9th, 2011, 04:54 PM
Does anyone know what this device is?

http://www.classic-computers.org.nz/blog/images/2011-12-10-trainer-programmer.jpg

I suspect it's some kind of trainer or programmer. Here is a large pic of the board.


http://www.classic-computers.org.nz/blog/images/2011-12-10-trainer-programmer-board.jpg

Other details are:

* Main CPU is a 1802
* The EPROM is the 1802 monitor
* There is an F key on the keyboard which will lock itself down, bit like a caps lock

Seems to work although lifting up the keyboard reveals two wires which have come away from their solder pads. I have no idea where they should go?

Tez

Chuck(G)
December 9th, 2011, 06:23 PM
1984 is a bit late in the history of the COP1802 training kits of this type. On the surface, it looks like someone's interpretation of the COSMAC ELF.

What's perplexing is the mix of standard 74xx series logic with 74LSxxx logic.

tezza
December 10th, 2011, 11:13 AM
Thanks Chuck,

I've now dug around a little and know more about the microprocessor and it's history. Yes, I suspect a design based on the ELF.

I'd love to find out who sold the board and what the primary purpose was. It has "Lang 1984" and the words "Commander" on the board. 1984 seems to me to be a bit late to sell these kind of general computer kits, when you could buy a C64 off the shelf. It has lots of connectors with tantalising lables like "BURNROM", READROM and RUNROM.

Do you think it could have been connected to an EPROM burner or at least had another piece of gear to accompany it?

Tez

Chuck(G)
December 10th, 2011, 03:54 PM
While it may (with the addition of a +25 volt Vpp supply) be able to program an EPROM, I don't think that programming is this thing's primary purpose.

Take a look at the PCB. While it does appear to have a solder mask, note that the vias are jumpered with short pieces of wire and that component holes use "rivets", rather than plated-through holes and vias that a professional PCB would have.

This may be a one-off.

MikeS
December 10th, 2011, 04:21 PM
I'd love to find out who sold the board and what the primary purpose was. It has "Lang 1984" and the words "Commander" on the board. 1984 seems to me to be a bit late to sell these kind of general computer kits, when you could buy a C64 off the shelf. It has lots of connectors with tantalising lables like "BURNROM", READROM and RUNROM. Those "connectors" actually look more like some sort of programming/option jumpers; what happens when you move the existing one?

I'm with Chuck; looks like a custom homebrew ELF.

Have fun with it!

tezza
December 10th, 2011, 06:09 PM
Hmmm….I’d be inclined to agree with you EXCEPT…

An acquaintance unearted a PDF (http://www.wpiinc.com/pdf/SM325_d30810-0110O.pdf)which described the MCL, a precision positioning system. This was produced by the German firm LANG GMBH & Co.

What it intriguing is this sentence on page 2 which reads…

“Interfacing the MCL with the LANG Commander
The LANG Commander is used as a console device for MCL/MCC positioning systems. Supply voltage for the Commander is 19VDC, not regulated. The voltage is applied to pin 1 of the RS232 interface connector by Jumper J7 inside the MCL.
This voltage is applied by a jumper to pin 1, if a terminal was supplied with the controller.
MCL – 2 jumper (bridge) 19 from board no. 070192
MCL – 3 jumper (bridge) 12 from board no. 070592
If using the LANG Commander , please be sure to use genuine interface cables supplied by LANG only.”

This is the only reference to the LANG Commander in the document. However the circuit board of this ELF –like machine has the words “LANG 1984”, then “Commander” at the bottom centre of the circuit board?

The jury is still out as the document seems to be 1997 and this machine of mine is 1984. It does say “LANG 1984” and Commander though? An early version made by LANG GMBH & Co. ? Circuit board only maybe, or a kit?

@Mike: Gotta figure out what it's saying to me first Mike, before I can make any sense of the numbers.

Tez

NathanAllan
December 10th, 2011, 07:19 PM
Not sure what it is, but Lang GMBH is still in business, might want to write a few emails:

http://www.langcomputer.de/

Very neat board, and it looks like maybe somebody took some excess or unused parts from Lang and made their own something or other. Learning about it is half the fun!!

Chuck(G)
December 10th, 2011, 08:15 PM
@Nathan: nice thought, but this Lang Computer appears to be a local retail store. Doesn't appear to make a thing.

@Tezz: Nope, not the same thing at all, just a coincidence. But I should explain myself. Let's look at the board and see what it can--and can't do.

Up at the top, we have the display. Three hex digits for address, two for data. So it can access up to 4KB, no more. You have the LED latch/decoder/drivers; I can't make out the part number, but they're probably Fairchild 9368, which have the unusual property that they'll display A-F as well as 0-9. Below that we see a 74LS174, hex flip-flop, which looks as if it's used to latch the 6 high-order bits of the address for PROM/RAM access.

We next have in the center of the board, an EPROM; probably a 2716. toward the left, we have a CDP1852 8-bit I/O port connected to an 8-position DIP switch.

Back all the way over to left, we have a terminal with a PCB legend that says +25. That's the EPROM Vpp--and the resistor and LED tell us that it's applied. We have a mass of jumper headers and a couple of terminals labeled for battery. The jumpers appear to configure the setup for `1 SRAM, or 2 SRAM (with one being in the EPROM socket). Burning, reading/verifying and executing from the EPROM seem to be other jumper settings.

Note the 2KB 6116 SRAM on left has two diodes. This is likely to allow a battery to be used to keep the SRAM contents alive while the unit is powered off. Note that below the 6116, we have a 74LS244 octal transceiver for both the RAM and PROM data bus. Below the COP1852, you see a transistor (probably something like a 2N2222), an LED, a relay and a jumper to select between the two. So you can blink an LED or activate a relay, whose contacts are rated at 1A (I assume that's what the legend means by the connector.) I'm not sure that the 3-pin connector above the relay does, but a little tracing should tell us.

Below the SRAM and transceiver we have the COP1802 CPU. Over to the left, we have what appears to be an oscillator using a 74LS132 quad Schmitt trigger with some jumpers to select the frequency. There's a 7473 (with a date code of 1974!) dual J-K flip-flop that's probably used as a divider. The mass of ICs around the 74150 16-bit multiplexer and the 74150 itself appear to be keypad-related. The slide switch labeled "RAM PROTECT" appears to disable writes to the SRAM.

So there you have it--a simple trainer. No serial I/O of any sort--and, in fact, other than the relay and LED displays and keyboard, no other I/O of any sort

It's possible that someone from the Yahoo Cosmac ELF Group (http://groups.yahoo.com/group/cosmacelf/) may recognize this thing.

tezza
December 10th, 2011, 09:36 PM
Many thanks for taking the time to type out that analysis Chuck.

I will check with that group you mention but at least I know what it is now. The fact that it the board says "Commander" and has Lang 1984 stamped on it does seem pretty coincidental. It's not beyond chance that Lang GMBH & Co did bring out a trainer in the early days and that they used the name "Commander" for later consoles. I might make enquires anyway. Half the fun is finding these things out.

Thanks again,

Tez

Chromedome45
December 12th, 2011, 02:57 PM
Box it and send it to me Tezza! I'll give it a good home...:D I have this thing for trainers. Finally got a SDK-86!

barythrin
December 12th, 2011, 03:23 PM
I'm just guessing but those readrom, burnrom, etc labels may be an interface to reflash that monitor rom that it has plugged into it.

tezza
December 12th, 2011, 04:55 PM
Box it and send it to me Tezza! I'll give it a good home...:D I have this thing for trainers.

Lol. Well you might be able to tell me how to use it :)

The numeric keypad is obvious enough. And I assume the A B C D E F keys are the Hex equivalent of 10,11,12,13,14 and 15.

What do the other keys on the two right columns do though? There is RS, L (load?), Rn (run?) and H in one line and F (which can click into place like a caps lock), ALT, something that looks like PU and the lower rightmost key is blank?

How do you actually use it? I'm assuming you should be able to load a number into the displayed address, then advance the address to add another number. I can display some values into the data LED but that's about all. The A,B.C.D.E.F keys seem unresponsive.

It could be that the machine is faulty of course.

Incidently I wrote a little article on it in my blog (http://www.classic-computers.org.nz/blog/2011-12-11-1802-trainer.htm).

@Barythin: yes, I agree with your conclusions here.

Tez

tezza
December 12th, 2011, 05:24 PM
The A,B.C.D.E.F keys seem unresponsive.

Ah ha! Found a broken wire and repaired it. These keys now work.

Tez

mnbvcxz
December 12th, 2011, 06:25 PM
Lol. Well you might be able to tell me how to use it :)

The numeric keypad is obvious enough. And I assume the A B C D E F keys are the Hex equivalent of 10,11,12,13,14 and 15.

What do the other keys on the two right columns do though? There is RS, L (load?), Rn (run?) and H in one line and F (which can click into place like a caps lock), ALT, something that looks like PU and the lower rightmost key is blank?

How do you actually use it? I'm assuming you should be able to load a number into the displayed address, then advance the address to add another number. I can display some values into the data LED but that's about all. The A,B.C.D.E.F keys seem unresponsive.

It could be that the machine is faulty of course.


Tez

My first "computer" was an MK14 which was a similar device to yours but it used the SC/MP microprocessor, it had a 20 key keyboard with 0-9 and A-F which allowed the operator to enter hexadecimal data into the machine, there were also 4 control keys named MEM, TERM, GO, and ABORT.
I would press MEM then enter a 4 digit hex address, then TERM to enter 2 hex digits of data into memory, I cannot remember the exact sequence but you get the idea, once I had entered a program into memory, pressing GO would run the program and ABORT would stop the program and return control to the monitor program.
On your machine I think RS is reset and H might be HALT.
I am sorry I cannot be of more help.

mnbvcxz
December 12th, 2011, 06:41 PM
If you can set the address at 000hex, see if you can read the data stored in the rom and then advance through the memory, after that you want to set the address at the start of free ram and try to enter a small program to see if Rn will execute it.
If you can find instructions on using the ELF it might make things easier.

mnbvcxz
December 12th, 2011, 07:01 PM
I see that the Cosmac ELF just had switches and leds so not likely to be helpful in using your machine, however the Netronics ELF 2 does have a hex keyboard and 2 digit led display and may be a closer relative of your (homebrew?) machine.

tezza
December 12th, 2011, 07:08 PM
Thanks for the comments.

Ok, I've done a bit more figuring. The blank key in the lower right goes to the "enter" pins on the board. Presumably that is what is does...ENTER the value.

What I thought said PU above that key probably is BURN (the black felt pen has worn off making it hard to read). The wires from that switch go to pins on the board with that label so I'm sure that's what it's suppose to say. The ALT key above BURN allows you to enter values IF held down (I think that key means ALTER). The F key above that is not attached to anything.

I'm not sure if ENTER works though. Pressing the key does nothing. I can't figure out how to put in the memory addresses and advance through them. No combination of keys seems to allow me to change the memory location.

So in summary I can add data values, but don't know how to advance to (or set) the next memory value. I'm also not sure if the ENTER key actually works. I'm wondering too what the BURN key does?

I'll keep playing. As I said, the unit could well be faulty.

Tez

barythrin
December 13th, 2011, 08:42 AM
heh have you made a backup of that monitor ROM yet? May come in handy ;-) If you're confident in it's state, I would think whatever button is your increment button one of those number will probably advance by one on the led display (just guessing though.. it's possible they assume you would know that or have it on paper and not need that), but you might be able to figure out what the buttons do with some mashing :-) That's of course assuming it has a usable rom and isn't just overwriting itself (though it looks like it's set to run the rom from that huge jumper set). I'm guessing (all of which I'm sure you already knew) that on off switch toggles the memory backup battery, then your first two rows of the jumper bank are whether you want to write (well or run) memory 1 or memory bank 2 vs running whats on the rom. I would kinda think you would be able to enter data via that monitor rom, back up the memory with that battery, then switch the jumper and next time you press the "Run" button it would run the code you did at those memory locations.

Out of curiosity, and maybe it's in your blog (guilty of still drinking morning coffee) but what's the story on this system? Where'd you get it from and what stories came with it?

- John

tezza
December 13th, 2011, 09:21 AM
Yes, I was eying that ROM yesterday thinking I should back it up...or even just check it to see if it makes sense. I'll do that today.

Key mashing. Good phrase. That's exactly what I was doing yesterday (pressing key combos) but there is no way I could get the address to set to what I wanted or to increment it. Resetting (RS key) seemed to send it to 020 after swtch on. At switch on it just seem to come up with a random address.

Either there is some step that's not obvious (and may have been in the manual...if one existed) or there is a fault somewhere.

As to the history, there is not much more than what I've written in the blog. I bought it with a couple of Apple IIes. If you follow that link in the blog it shows a flyer for the large sell-off event I got it from. No one there could tell me of it's history though. It's a complete mystery. Although the keypads and case are obviously home made, my feeling is the board is not just a one-off. It's got that LANG Commander inscription and someone has taken a lot of time to label the board well. That's not to say there might have only been a few dozen made though.

The board could be used as the nucleus of a computer. Those solder pads at the top are the address lines, data lines and a few other CPU lines (and are labelled as such). Someone who knew what they were doing could interface it to an I/O device if they had the inclination.

Tez

mnbvcxz
December 13th, 2011, 09:55 AM
Do you have the 1802 datasheet?, there is a pdf on wikipeadia's 1802 page, if you have a logic probe you may be able to see what the processor is doing.

tezza
June 7th, 2012, 02:18 AM
Apologies for resurrecting an old thread but I'm pleased to report the origins of my strange RCA CDP1802 ELF-like trainer (http://www.classic-computers.org.nz/blog/2011-12-11-1802-trainer.htm) has been unearthed.

Seems it really was homegrown, being designed by a tech. teacher for the local community college in the town I bought it from. His name was Dave Lang hence the LANG COMMANDER.

See https://sites.google.com/site/walztronix/electronics/1802-projects

Mystery solved. Many thanks to the guy who left a comment on the writeup page and included the sites.google link.

Tez