Digiac 2000 MAC-III 6502 trainer

[GrubZero]

Hi All.

Just a quick progress update.

I’ve successfully managed to dump the ROM image but have a question.

Would I be violating any copyright laws by uploading the ROM image?

I’m new to this game so I’m treading carefully.

Now that I have the image I’d be happy to post the original EPROM to James if that keeps everything above board.

Any advice would be greatly appreciated.

Cheers

Pete

[gw0udm]

That's great news!

On the copyright front... I'm sure it is true that the company own the copyright although at the same time when I contacted them they seemed to have no real memory of the device at all, let alone any kind of continuing commercial interest (eg they did not offer to sell me a new EPROM, for example!).

So I would have thought there would be no harm in publishing the image... although if you'd like to send me the EPROM of course that would be most kind!

It's pretty much useless without the original board anyway.

Does anyone else have a view?

James

[BigEd]

I'd say there's no harm and no real likelihood of trouble, but sharing privately might be a good first step.

Like many things, people have their own views on this sort of thing - some like to adhere strictly (where the next step would be to seek permission) and some like to go full ahead. It's a little like speed limits.

Personally I think it would be great for the ROM to be out there, and for this board to feature in an emulator like MAME. Which is pretty likely, if the ROM is shared, because the hardware is very like several other minimal 6502 boards.

[GrubZero]

Hi All.

Thanks for the advice, I’ll PM the Rom image to those interested when I get a minute.

If you PM your address to me James I’ll post the EPROM on to you, I’ll include the Applications Module too as I’m sure I’ll never get round to using it.

Thanks again All & sorry for late reply.

Cheers

Pete

[gw0udm]

GrubZero wrote:

Hi All.

Thanks for the advice, I’ll PM the Rom image to those interested when I get a minute.

If you PM your address to me James I’ll post the EPROM on to you, I’ll include the Applications Module too as I’m sure I’ll never get round to using it.

Thanks again All & sorry for late reply.

Cheers

Pete

Coo thanks very much, that's very generous - I'm PMed you

James

[maniacminer]

gw0udm wrote:

GrubZero wrote:

Hi

No problem at all, more than happy to help if I can & hopefully learn something new myself while I’m at it.

Here is a link to what I got hold of. Unfortunately is a bit sparse although the brochure is quite cool:

https://1drv.ms/u/s!As5Cnv80l9bphsR-sX2 ... A?e=s6OHpa

The most useful bit is probably the user manual, you have got in effect the complete system with the applications module too which is very nice. The monitor includes some routines which run on the applications module, and the details for that are in the manual.

James

Thanks for the link, I have a whole pile of these boards given to me a decade ago and now I'm finished with the Unilab 3-Chip-Plus board restorations, I got started on these. I don't even have the case, just the boards and applications boards, the press G and type F600 then G again lets me try out the various bits of the applications boards and trace out problems (there are lots!) Without an AC power supply there is no -5V supply for the applications board that requires this extra rail for op-amps and the additional 5V rail to drive the LEDs, transducers and motor. With everything running the total load is 1.5A on the 5V rail and 45mA on the -5V rail.

[BigEd]

(Welcome, maniacminer! We've only had one mention of Unilab boards before.)

[xango]

I have the board with EPROM 27C256 if you want I can dump it and send you a bin.

[BigEd]

Welcome, xango, that would be good! I did ask Pete for a copy but I see now that it didn't arrive.

[Dr Jefyll]

Welcome, xango! Thanks for stopping by. Feel free to stick around... and to maybe tell us a bit about yourself or about your experince with the Digiac trainer!

-- Jeff

[gw0udm]

Just as a quick update, I was very kindly sent the various boards mentioned above including the EPROM and I have now got the monitor working. I need to write it up and take some pictures. Unfortunately I don't have the means to read out the EPROM image at the moment.

[Davegsm1982]

Hi Everyone, I'm hoping I can throw myself on someones mercy.

I'm looking for some photos of the top and bottom of the Keypad/display board of the 6502/68000 trainer systems (as far as I know they're the same board) as I'm looking to recreate one.

I have a 68000 system board that I would love to have working but it has no Kb/Display board, I would love to find a 6502 main board some day too if anyone has one of those available.

Thanks!

[Dr Jefyll]

Welcome, Davegsm1982

With luck, perhaps someone will be able to help. But your request seems a bit confusing (to me, at least). First of all, I didn't realize the Keypad/Display was actually a separate PCB until I took a closer look at the photo in the lead post.

Also, you mention "6502/68000 trainer systems," and, "as far as I know they're the same board." But do you perhaps mean 6800 (rather than 68000)? And, it might be helpful if we knew what the 6800/68000 system is called. (I'm assuming it doesn't have the same name -- Digiac 2000 MAC-III.) Cheers!

-- Jeff

[Davegsm1982]

Dr Jefyll wrote:

Welcome, Davegsm1982

With luck, perhaps someone will be able to help. But your request seems a bit confusing (to me, at least). First of all, I didn't realize the Keypad/Display was actually a separate PCB until I took a closer look at the photo in the lead post.

Also, you mention "6502/68000 trainer systems," and, "as far as I know they're the same board." But do you perhaps mean 6800 (rather than 68000)? And, it might be helpful if we knew what the 6800/68000 system is called. (I'm assuming it doesn't have the same name -- Digiac 2000 MAC-III.) Cheers!

-- Jeff

Hi Jeff, Thanks for the welcome.

Yea, the 2 boards were separate, and as far as I know you could use some terminal software to upload code to the main board via RS232 and not bother having the keypad/LED display so it was sort of optional, but I never once used RS232. Everything was manually and labouriously entered on the keypad.

I'm hoping someone will be able to oblige as I used this system when I was in school and I really want to get it going again. I have all the parts to populate a display/KB PCB but I can't find any good photos of the rear so I can't begin to reverse engineer it. The display IC is self explanatory but I don't know how the keypad is multiplexed.

So yea, there were (to the best of my knowlege) 3x DIGIAC Microprocessor trainer systems;
6502 - MAC-III
Motorola 68000 - 'TIM 68000'
Z80 - Not sure.

I used the 6502 a lot and did a small amount of work on the 68000. I absolutely adored playing with the 6502 which prepared me well for when I started programming PIC microcontrollers with assembler.

Regards, Dave.

EDIT: Just realised, when I said 'they're the same board' I meant the display/Keypad is the same board shared across the 3 microprocessor trainer systems. Sorry for the confusion.

[Dr Jefyll]

I've begun a very hasty web search, and some of the photos in this listing show remarkably good detail on the top side of the keyboard/display PCB. Incomplete though it is, this might reveal enough that one could deduce and/or experimentally determine the unknown connections.

Do you have a schematic for the main board to which the keyboard/display PCB attaches? If so, that'll tell us a lot about the signals carried by the ribbon cable. You'll also wanna hunt up a datasheet for the ICM7228A IC -- the one that apparently scans the key matrix.

Edit: here's the datasheet. And actually that chip's job is to drive the LED display.

-- Jeff