Digital Group Z80 - almost working

[Getafix]

Hi Marty,
I am trying to build up a library of everything I can find for the digital group machines. I want to make sure it gets preserved somewhere (other than just bytecollector.com which will go away at some point I suspect. Some things are in the internet archive but that’s far from complete). If you have a scan of the listing, I would love to have a copy!
Thank you, Marty
- Stefan

 

[Marty]

Hi All;
Stefan, I would estimate there are about 350 to 400 Pages of Listing, just to let You know.. Not that it can't be done..
I am going to scan another document that is closer to 20 pages.. And You can mull over that, it is for the 8080 DG Cards, I had two of them, but they went to Bryan Blackburn.. And I would Guess, that Bryan has sold some of His collection, as I have seen some of my old cards on another site..
THANK YOU Marty

 

[Getafix]

Hi Marty,
If you are willing to temporarily part with it, you can send it to me, and I’ll send it back to you after scanning it. I’ll even pay for postage both ways. But I’ll totally understand if that’s a bridge too far, though.
If you have a copy centre near you I’d also be willing to pay for them to scan it, if that’s a possibility? I would really like to see it preserved.
Thank you - Stefan

 

[Marty]

Hi Stefan;
I Like that Idea, How can we make it work ??
I would be Glad to Send You the Notebook or two..
I'LL have to check what all I have..
On another matter, though similar , If You go to Youtube and look at the Video's He made, I recognize some of the Boards ,
as one's I used to have..
Go you the Rise and Fall of the Digital Group at about 18:05 into it, He shows the Back of a Board, it is a Phi-deck Board,
with an R-pack added with Orange wires going to it.. I added that R-pack to that Board..
And if You go to His Other Video on the Digital Group, it shows an 8080 CPU card, I am sure that, that board is one of my old Boards and in the back of the 8080 motherboard it barely shows a TVT-32 Card, but it had a Mod in the upper Right hand corner for reading the Cassette and the Ic's are mounted (glued) upside down on the Board.. I did not do that Mod, but I recognize the Board.. I had that Board..
The guy doing the Video's is Tech Time Traveller..
P.S. I would really like to see what all is in the Notebooks preserved..

THANK YOU Marty

 

[Marty]

Hi Stefan;
Here is attached (hopefully) the 8080 pages that my friend marked up for what would eventually become ICOSE..
This first section is for the EPROM Pages..
Also, If You are able to make a new Eprom for Your DG, (1) I would do so, to preserve it's contents..
(2) But, when doing so change the Sign-on Message from
" Read z-80 Initialize Cassette" to "Initialize z-80 Read Cassette"

THANK YOU Marty

 

[Marty]

Hi Stefan;
Here are the next 10 scans of the marked up 8080 OP SYS pages..
I think this will be the first Third of what I will be sending You..
I Don't think He did anything with the Z-80 Listing..
Since He got rid of His Digital Group Machine and got a "Spacebyte" 8085 (S100) System with Floppy Disks..
And He Re-wrote the Operating System for that system, just like He did this one..
And I have some and a cut down version of that on my Spacebyte card..
THANK YOU Marty

 

[Getafix]

Hi Marty,
If I understand this correctly, the octal codes are the Z80 instructions and the comments describe what's going on. The hand-written notes are the 8080 translation of the listing. Is that right?
Who wrote ICOSE in the first place (if I am correct, in other words the Z80 version)?
Thank you - Stefan

 

[Marty]

Hi Stefan;
NO, these are 8080 op codes, only, what You see is His own Mnemonics for the codes and His assessment of what the Program is doing..
You will be getting in the Next installment a couple of pages with the Definition of His opcodes..
What is attached is the Second installment of 10 pages for the 8080 OP SYSTEM..
I only, had ICOSE #68 and ICOSE #73 Listings, I wish I had earlier Listings, but, I don't and I am fortunate to have even this..
I can ASK Him (which I just did, I am waiting for His email answer) and See if He has come across anything else, in the Last few years.. But, I suspect they have been lost in time..
His name is Denis Bourdeau..

THANK YOU Marty

 

[Marty]

Hi Stefan;

There are about 60 more files to Transfer to You today.. At a rate of about 10 to 12 at a time.. I can see if it will let me do 15 at a time, but, no promises..
Also, are You a Hardware Person or a Software Person or both ??
As I have an idea to maybe get You more Memory..
One, that I don't like is that You see if You can get some more 8K Boards, I used to have a couple of 32K Boards, but, I no longer have them, and I don't know who they went to, any more.. I don't like this idea, because, the 2102's are old and somewhat unreliable..
But, my other idea, is get a blank S-100 Wire Wrap Board.. I know that the S-100 boards are slightly taller and narrower.. Cut or file the amount of fingers, till it matches the amount of fingers on a Digital Group Memory Board..
Get about 10 TM6264 8K Memory Ic's and wirewrap sockets for them.. (You only need 8 of them, but getting 10 gives You two extra Memories..
And some (maybe 10 each 14 pin and 16 pin wirewrap sockets, and make Your own 64K Memory Board..
I know this depends on Your Hardware skills, but I bet there are plenty of people Here that could Help You with a circuit that would work on Your DG..
I once had a 64K Memory Board for the DG that used similiar ic's, only they were 6116's instead, but, basically the same idea..

THANK YOU Marty

 

[Marty]

Hi Stefan;
It will only let me do 10 at a time..
THANK YOU Marty

 

[Marty]

Hi Stefan;
The next group..

 

[Marty]

Hi Stefan;

Next group..

 

[Marty]

Hi Stefan;
More of the same..

 

[Marty]

Hi Stefan;

More getting toward the end..

 

[Marty]

Hi Stefan;

Last of them for Now..

THANK YOU Marty

 

[Marty]

Hi Stefan and All;

This should keep You busy for at least 5 minutes..
THANK YOU Marty

 

[Getafix]

Hi Marty,
Wow! Thank you. That’s a lot of reading.
I am really a software person but I have good tools (soldering iron, scope, bench power, etc) and I am in the process of learning more electronics.
Maybe I can get PCBs made? That’s pretty inexpensive these days. Would be fun to do the layout if I can get images of what they need to look like. I’ll follow up with you in a DM. That would be a learning thing for me and will take some time (and I have time
Thank you - Stefan

 

[Marty]

Hi Stefan;
I would suggest that a wirewrap version be done first, to get all of the kinks out of the circuit, unless, You can find a circuit that is already working and tested.. That way You don't waste money on multiple PCB's..
I forgot to say that the order of things in the manual, were not in the first part of what I copied..
So, You can arrange them as You like, or I can tell You, what went where in the ICOSE Appendixes for the Manual..

THANK YOU Marty