PICOSMAC - Back to the Past (Nuts and Volts Magazine)

[Chris Savage]

PICOSMAC - Back to the Past (Nuts and Volts Magazine)

This is a story of a nostalgic, useless, but fun project that spiraled out of control; a lesson in the lost black art of machine code from the bygone era of code written and debugged on square ruled paper, from an era of hand-drawn schematics and actual manual tape-out of chips.

[granz]

Very cool. I actually had one of these VIPs, along with an Ele II. I also still have one of the COSMAC 18S020 evaluation boards (and it worked last time I tried it, several years ago. )

The name, Picosmac, reminded me of the project that implements an original Mac computer on a Pi Pico. I bought one of these, and it is pretty cool, however I still need t build up the HD image on the SD card.

That Picosmac is another cool project and also reminds me of the Kimuno - an emulator for the Kim 1, as Al Williams (from Hack-A-Day) wrote a COSMAC Elf emulator for that KimUno. I need to me careful not to dive into that Picosmac as I still have too many projects on the front burners (and several more on the back burners. )

[Chris Savage]

...an emulator for the Kim 1...

I had a KIM=1 briefly in the early 90s. It was my introduction to CP/M, before I ever really use DOS.

[granz]

KIM-1? Are you sure about that?

The KIM-1 ran on a 6502, CP/M ran on 8080/8085/Z80 systems. It wasn't until just recently that someone wrote a CP/M-ish OS for the 6502.

[Chris Savage]

KIM-1? Are you sure about that?

Now I am questioning my memory of the time...in the early 90s I had several machines that I ended up getting rid of before I could really do anything with them because money became short in 1992 and I had to prioritize.

I remember having a KIM-1 and, from the same person I had gotten an SX-64. There were others. But TBH, I don't remember which one had the CP/M on it. I remember that I had some weird stuff...I had a TI-99/4A, and even some Coleco computer with dual-cassette decks. I remember that I was trading trying to get a Timex Sinclair, but nobody in my area had one.

Oh yeah, through the 90s I had eventually had several Tandy CoCos...all three models by 1994. Of course in the late 80s I had an Apple II. But as I sit here, I realize there are some I don't remember the details. OH! The Coleco was Adam! I also had an Atari 800 at once point. Then when I got into MIDI, I had acquired an Atari ST. Still can't think which machine had the CP/M on it. 

P.S. - I NEVER owned a PC before Commodore went out of business.

[granz]

The Adam had a Z-80 processor, an IIRC there was a CP/M version for it - I believe that they treated the cassettes as disk drives. Once, while I was on an exercise (war game) down in Florida, I befriended the base librarian. She had an Adam, and asked me to review it for her. The thing was supposed to be Apple-like (really? with the wrong CPU? ) and the documents were so terrible that I ended up using an Apple book to figure out the BASIC.

There were also Z-80 add-ons for the Apple, and the Commodore, which provided CP/M capabilities.

There was an S-100 add-on for the KIM-1 (I had three different KIMs, one of which was an original MOS Technology KIM-1, and one of those had the S-100 attachment) and, again, if I remember correctly, there was a way to disable the CPU of the KIM, and replace it with a Z-80.

Maybe your CP/M memories came from one of those.

[Chris Savage]

The Adam had a Z-80 processor, an IIRC there was a CP/M version for it - I believe that they treated the cassettes as disk drives. Maybe your CP/M memories came from one of those.

It was probably the Adam. I didn't have it very long. I remember almost nothing about it.