CP/M

From: Jack Peacock <peacock_at_simconv.com>
Date: Sat Jun 13 18:10:53 1998

+AD4-Did MP/M run on Z-80s? BTW, is there a reasonable chance the CP/M on
+AD4-one micro w/5.25+ACI- disks be compatible with another with 5.25+ACI- disks,
+AD4-i.e. my apple with a C-128? Also, if a computer can run CP/M 3 can it
+AD4-run eariler versions? (Note i'm not talking about apps here).


Yes, MP/M ran on the Z80 first, then on the 8086. A multi-user Z80
was no speed demon but it was cheap compared to a PDP-11. BTW, the
very first initial release of MP/M was actually coded for 8080, the
task dispatcher did not save the extra Z80 registers. I discovered it
the hard way, reported it to DRI, they fixed it right away.
Apparently whatever machine they used to test MP/M was 8080 or 8085
based.

Compatibility on floppies was about nil, very very few disks could be
moved from one machine to another. If anything, 5.25+ACI- compatibility
was worse than 8+ACI- floppies.

Any Z80 machine that could run V3 had all the hardware needed to run
V2. CP/M V1 was designed only for 8+ACI- SSSD floppies, the BIOS didn't
have the drive tables in it to support anything else.
        Jack Peacock
Received on Sat Jun 13 1998 - 18:10:53 BST