“A Zilog computer”? “To implement the CP/M language”? Maybe he implemented a hardware emulator of a Z80 CPU using a Parallax chip and built a CP/M-running computer around it?

I’ve been watching this project unfold on the Propeller forums. Yes, it’s a software emulation of a Z80 and a complete Z80 I/O system including disks and UARTs (and, in other form factors, modern keyboard and video). While the hardware tech isn’t old the key is that the software tech really is; it’s a complete functioning CP/M system supporting all the compilers and dev tools that were around in the 1970′s. It’s a pure trip into the past, much more useful than it has any right to be, and the original hardware was more suitcase than matchbox sized.

CP/M is an OS, not a language (ah, CALL BDOS!).
Zilog is the foundry for the Z80 processor, and it was still very much alive in the 80′s (http://en.wikipedia.org/wiki/CP/M).

It reminds me of those poorly written articles in newspapers, where you can read stuff like: the pilot of a small Cessna, a Piper PA-28, landed on a golf course… Any aviation enthusiast can catch this one.

So, Mike, are you an enthusiast?

I’ve made a couple SBCs from Zilog chips over the years, last one had less component mesh and the 20MHZ chip. They are fun to program and learn assembler and real mode, the propeller I think can do assembler too but it has a locked ROM. It’s be just as easy to do this with an actual Zilog processor, but you’d need controllers for some stuff.

tj: Actually it is EASIER to use a Propeller and ZiCog emulation than a real Z80.

One can use a single 40 pin DIP Propeller MCU and a 64K RAM chip to emulate the Z80, the console I/O, the floppy/hard disks AND the Video display (80 * 26 chars). Complete CP/M system the size of a cigarette packet on a home made PCB all solderable by hand.

See what these guys have been up to http://forums.parallax.com/forums/default.aspx?f=25&m=405722&p=1

It’s the same thread as the original picture here but you will find examples of simple CP/M boards there.

The real question is… Where you get those redhead matchboxes?

Yeah, but can it run Wordstar? That was the standard in its day. If it can’t do that then it’s not fully compatible.

The Propeller strikes again!

@Rex: Yes, it does run WordStar.

@Roly: Strangely enough I have a half finished 6809 emulation for the Propeller. Hope to be running FLEX and CUBIX on it one day. Someone else was working on a 6502 not sure of it’s status.

Smaller, faster, cheaper! The Propeller is an amazing chip.

Yes it can run wordstar http://www.smarthome.viviti.com/propeller and indeed Wordstar is one of the “proof of concept” programs being used (along with BDS C, Microsoft Basic and SBasic).

The board in the above link is the DIP package version and is self contained with vga driver, keyboard driver, hard drive etc all on one board. The propeller can do graphics too (even Castle Wolfenstein).

And other chips can be emulated too – it is just a matter of going though each instruction and making sure the flags are set correctly and that it does what it is supposed to.

Re using a real Z80 – there are boards out there that can do that http://www.smarthome.viviti.com/build

But they are bigger, use more power and while they can do a keyboard and a small 20×4 graphics displaym, they can’t drive a VGA or TV like the Propeller can.

This matchbox sized computer replaces something that weighed at least 20kg. Matchbox computing for the masses!