Unknown S100 system

Chuck Guzis cclist at sydex.com
Fri Sep 21 15:01:05 CDT 2007

On 21 Sep 2007 at 14:07, Roy J. Tellason wrote:

> I wonder why they went with that part?  I seem to remember some others that 
> used it as well,  though specifics are not coming to mind at the moment.  I 
> have a bunch of those on hand,  and think about doing something with them 
> from time to time.  It's a fairly easy chip to use,  with an eprom and a ram 
> chip and a single address latch,  I just haven't decided yet what I'm gonna 
> do with it.

Compupro 85/88 board; my own Durango F-85 and a host of others.  If 
you can find some of the support chips (8155, 8755), the parts count 
can be very low, given the vintage of the 8085.

I suspect that the reason 8088/8085 pairs were fairly common in 
comparison to Z80/8088 pairs was that timings and buses on the 8088 
and 8085 are *very* similar and getting them to work with 8000-series 
peripherals was very easy.  IIRC, one could even replace an 8085 with 
an 8088 (assuming you were restricting it to 64K addressing) with a 
minimum of "glue".  Both multiplex the data lines on A0-A7 the same 

I suspect it might be easier to substitute an NSC800 for an 8085 if 
Z80 functionality is needed than trying to shoehorn in a Z80.


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