26 Apr
2018
26 Apr
'18
5:50 p.m.
> I believe the Z-80 was subordinate to the M68K.
On Fri, 27 Apr 2018, Eric Smith via cctalk wrote:
In high-level conceptual term, maybe, depending on the
software.
In term of the actual capabilities of the hardware, the Z80 was firmly in
control of _everything_ in the machine, including control over the MC68000,
while the MC68000 had no direct control over anything but its MMU (built
from TTL) and memory. If code running on the MC68000 wants to talk to
anything at all, disk, tape, console, printer, serial ports, etc., all it
can do is politely request that of the Z80. In that sense it's like the CPU
of a CDC 6600, which can't do anything without the PPUs
So, the Z80 ran CP/M and TRS-DOS, functioning as in I/O coprocessor for
the 68000, . . .
As in small business, which is "subordinate",
engineering or administration?
A friend of a friend was very proud of his Z80/68000 Cromemco. He was a
little offended when I compared it to the Radio Shack Model 16.