Dennis Lee Bieber wrote:
On Fri, 25 Sep 2009 14:22:51 +0000 (UTC), Grant Edwards
<inva...@invalid.invalid> declaimed the following in
gmane.comp.python.general:
EXX accomplised much of the context switch operation. I don't
remember how much RAM was available, but it wasn't much...
Zilog Z80... as with the rest of the "improved" 8080 family -- 64kB
address space...
I knew of one Z80 implementation which gave nearly 128k to the user.
Code was literally in a separate 64k page from data, and there were
special ways to access it, when you needed to do code-modification on
the fly. The 64k bank select was normally chosen on each bus cycle by
status bits from the CPU indicating whether it was part of an
instruction fetch or a data fetch.
Actually even 64k looked pretty good, compared to the 1.5k of RAM and 2k
of PROM for one of my projects, a navigation system for shipboard use.
DaveA
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