Wanted: Just about anything IMSAI

From: Allison J Parent <allisonp_at_world.std.com>
Date: Sat Feb 6 09:31:59 1999

<Compupro made a Z80 slave card that supported between 64K and 256K or RAM
<that had a RS-232 port. If I recall correctly you could only put 8 of thes

I don't see it in my old catalogs. the closest one was MPX-1 with an 8085,
16k ram, Transient master and interrupts(8259a).

Teltek, Konan, Macrotek and SDS did make them however.

<There was another method of placing multiple CPU on your bus. That basical
<ment building a Single Board Computer (SBC) that could use the S-100
<Temporary Master Access (TMA) hand shaking. The S-100 supported up to 16 o
<these TMA on a bus. The advantages is the TMA's tended to use the bus more
<efficiently comparied to slaves boards with requried a bus master present
<servicing them. I don't know who use to make SBC that fully IEEE 696
<standard for TMA access but do know that they were out there.

Been there done that. Used 4 z80s in a symetrical loosely coupled
multiprocessing system. One requirement is local and public pool memory
that any DMA (device or transient master) can address.

Allison
Received on Sat Feb 06 1999 - 09:31:59 GMT