View Full Version : Commodore BX-256-80 - 8088 Co-processor

December 23rd, 2008, 06:53 AM

It (more or less) works! Last night I installed the co-processor into a working system.

December 23rd, 2008, 05:51 PM
Nice looking computer Bill,

I love the curvy retro look of those machines.


December 25th, 2008, 02:41 AM
So, is that a special version of DOS running on this 8088 system? I suppose it doesn't even emulate IBM character graphics to its fullest, but a bundle of programs should run nevertheless.

December 25th, 2008, 07:03 AM
Microsoft supplied Commodore with the source code, Commodore created a BIOS that'd work with a B Series system using the 8088 co-processor. It was really just a shop experiment (Commodore never sold 8088 co-processors so the DOS was never released), there is no DOS software for the B series. I only have the one boot disk (I have uploaded a copy to my web site if anyone is looking for a copy)
Merry Christmas

February 3rd, 2009, 09:10 AM

Nice find! The number of known remaining 8088 boards is increasing. My understanding is that there were only 40 made in total, of which under 10 are accounted for. I have one as well but have not installed it yet. I'm not sure if the board works.

Have you tried running ANY other software? I assume that anything that fits in memory and does standard BIOS calls should work. Hardest part will be transfering software from PC to 8050 disk...

Commodore had full intentions to release machines with the 8088 board as can be seen in their spec sheets and press releases. It's a shame the CBM-II machines never took off.


February 5th, 2009, 04:30 AM
I have had dBase II and Wordstar running in CP/M 86. I also have a Z80 emulator that runs in CP/M 86 mode. This allows me to run a few other things. The problem with the whole co-processor is that it's unstable and crashes frequently. I am behind in my work, but I plan to experiment with this further. The computer is on the bench at the moment, I plan to try another motherboard in my 256-80 to see if that helps with performance.