On Friday 21 September 2007 16:01, Chuck Guzis wrote:
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.
Compupro was the one that was hanging out there at the edge of recall...
I may have some of those support chips, too. 8155 (and 8156, which is the
same part with a different select pin polarity if I'm remembering right)
sound real familiar. I have the 8085 Cookbook and a few others that Sams put
out, one covering this text editor and assembler (which I didn't really care
for, but...). No interest in the ROM-based 8355 and I've never seen the
EPROM-based 8755. The relative i/o and RAM address mapping of those parts
gets a little confusing, though, and the book is a bit less clear than it
could be on that aspect of it.
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
way.
Ah.
I'd never really looked at the 8088 and later parts all that much, or to that
level of detail.
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.
That's another part I have no familiarity with at all at this point in time,
though of course I've heard of it.
With regard to what little programming I've done, the thing I like most about
the z80 is relative jumps, which makes relocatable code easy to do. The
other big deal is the alternate register set and the index registers, which
I really haven't used all that much.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
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