View Full Version : TI 99/4a Z80 card

September 30th, 2008, 10:18 PM
A friend is looking for info on the Z80 card for the PEB.
I myself know nothing - anyone got any info, or know of one available?

Docs, schematics, anything, really!


October 5th, 2008, 06:36 AM
There were two different commercial Z-80 cards for the TI.

One was produced by MorningStar and used the Osborne-1 disk format. Maybe 30 of them were sold, with the rest still in the manufacturer's basement many years later. Partly due to the price ($600 or so), but also due to the fact that interest in Z-80 machines was starting to die at the same time as this board came out.

The other was built by Foundation Computing and used a CP/M binary workalike called RP/M by MicroMethods. It used the Kaypro2 disk format. I have this card, partial docs, and a disk that might have the O/S on it (the disk was damaged when sent to me--and I knew it when I got it, but I plan to try and recover the data files when I get some time). I know of exactly three copies of this card that survive (though there may be a few more hiding in closets somewhere). I also have a Kaypro4 disk that the jack Dennon of MicroMethods is pretty sure has the RP/M O/S on it, but I haven't been able to test that yet either. Work has kept me pretty busy for the last year or so. . .

A hobbyist I know also built a homebrew card two or three years ago, but documentation for that wasn't released.