13 Responses to Downloads

  1. Chris Mallam says:

    It was all polling, no hardware interrupts.

  2. James Whitmore says:

    I built a DG computer from kits the company supplied. I figured there were about 14,000 hand soldered joints in the finished product. I did some trouble shooting with a simple pen style logic probe, and found a small defect in a printed PC board that kept a “555″ timer chip from oscillating. After I repaired the board, everything started working.
    It took me almost 2 weeks to figure out that in the documentation meant to push the enter key. There was no person I knew (at that time) with computer experience, so I was on my own. The audio cassette tapes worked fine for loading software, but my 4 deck Phi-Deck box never did work, even after much fiddling. The heads would load, the motors would run, but I never got a reliable data transfer. No access to a oscilloscope back then, and to expensive to buy one. I wire-wrapped a board so I could switch from the audio cassette ROM to the Phi-Deck ROM by flipping a toggle switch. I would say I learned a great deal, but never got any really good use from that PC. Mostly I played lunar lander and chess with it. I think I had about $2000 (“real” 1975 dollars) invested in the Digital Group setup. I think it still works about the same as when I built it, except the foam pads in the DG keyboard are shot. I got an E-mail from a guy who replaced the foam on his keyboard, so I guess it can be done if enough time is available. I thought DG was the LEAST likely company to fail, since it seemed the most flexible. I was certainly wrong, but DG did supply everything I paid for in total while slipping into bankruptcy.
    I replaced it with an Ampro “Little-Board” single board computer running CP/M 2.2 on 5 1/4 inch floppies. I put the Ampro PC into the cubical case that the Digital Group monochrome monitor came in, along with a power supply, and a “BG Micro” terminal board, that emulated a Lear-Sigler, Heath-Zenith, or DEC terminal. Worked great, and still does to this day, using the “T-Maker” integrated office software package, in 48 kilobytes of RAM.
    Too bad about DG, but I probably made back many times the $2000, because I was the only person who knew anything about microprocessors when they started showing up where I worked.
    Jim Whitmore

  3. Bob Luman says:

    How do you register with this group?
    I have 2 big brown boxes with motherboard and power supply as well as a DG keyboard. I have not turned them on in years. I started with a minimum system while I worked for HP in Orlando. When I moved to AL in 77 I got a system for a local accountant and wrote the software he needed for his business. I hated to see the DG go away.

    Thanks for starting this site.


  4. Landon Dyer says:

    I built a DG system in 1978 — for a while I was the only kid in our high school with a computer. Added phidecks after about a year of fun with audio cassettes. I learned a LOT from it (got CP/M running on it, using an Atari 800 floppy disk drive for storage, and got it hooked up to the Arpanet using a terminal emulator I wrote).

    I think it would still work, if I replaced the foam on the keyboard. I doubt there are any 300 baud BBS systems to dial into any more, though, much less an Arpanet TAC :-)

  5. Bob Luman says:

    Does anyone know where any info is available on AEON boards made for DG computers? I have a system with a Z80B processor on a daughter board that I think is an AEON board.

    • Bob Luman says:

      Previous comment is incorrect. The board turned out to be a R W Sales processor board with a sasi interface on the daughter board. I actually found my old documentation for it although the print quality is poor. I wonder if the sasi interface works directly with a shugart drive. I also found OASIS docs.

  6. Philip says:

    If I remember correctly that daughter board connected to a hard drive interface which in turn could connect to an ST-506 type hard drive. Rex (the “R W” part of R W Sales stands for Rex Widmer) eventually made new/updated versions of most of the DG boards including the motherboard and also created new boards which had no DG equivalent.

  7. Bob Luman says:

    Hello All,

    The January 2013 issue of “QST” magazine has an article abour Dr. Bob Suding, W0LMD, that includes a mention of Digital Group computers. Check it out.


  8. Dan Howell says:

    Wow. Seeing “Read Z-80 INITIALIZE Cassette” on my computer screen and the numbers zip across the screen really brings back memories. This was my first computer (I was 11 years old). A few years later we donated the computer to my junior high school where I actually taught their first computer class.

    Anyone know where I can get a hold of the original full BASIC (not Mini-BASIC) interpreter for this?

  9. Tom Lake says:

    How do you start the emulator in 64-column mode? 64 column BASIC looks odd running in 32 col mode.


  10. Tom Lake says:

    Does anyone have a copy of MAXI-BASIC in bin format that would work with the emulator?


  11. Jim Walton says:

    I have two systems one that I built in 77. and one I ordered to resale as a dealer in 78. It is a kit still. ( boards and cabinet ) I am still A DEALER but Apple only. The oldest dealer in Tennessee. I have couple of boards made by others. Didn’t get everything I ordered and paid for, but Dr. Suding and team gave me a direction in my career as a microcomputer and I wild ride from Hobby to Mainstream. I still have dealership and are semi-retired with daughter running operations.

  12. Dean Logan says:

    I bought a DG machine in 1977. I still have it. My goal is to power it up. I understand that the keyboard needs to be rebuilt and that I should use a varistor to slowly in crease the input voltages to the power supply and hope the capacitors do not burn up. When I get ready to start this process can I get some help from you?

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