I have a multi processor using the SC/MP both the first 8A500 pmos then later 8073.
I have a board I made up with the Nibble basic rom version too.??Their basic issue
was paged the unique 12bit addressing and they were slow compared to 8085 and z80.
When you put cores together on the same silicon you likely have access to the
internal machine and syncing them gets a lot easier.? The yabut is the software
still has to know it has resources and how best to use them to advantage. So
getting multiple cpus to work and share data was easy but Multiplan and Editors
had not one clue?they had additional CPU(s) to work with so no advantage.?
The system software I did take advantage of that but it was far from portable
as it had to know about the resource to use it being CP/M BIOS was the first
place?for devices? to appear.? THe second was doorbell and system control blocks
(SCBs) that were ways to transfer messages, commands, and status.??The
first multitask/multi-user boxes built around MPM and CP/M-3 new of networking
but the number of thing it could do were again not limited by hardware but
applications software so must software at best to print remotely but even then
the software was dumb.
At the time I was also using VAX and PDP-11 systems with multiuser and multitasking?
OSs at their core so as a z80 (z180 and Z280 as well) user it seemed we never got
to a more complete and effective OS with applications in the 8080/8085/z80 realm
of 8bitters.? For the moment Chromix and UZIunix are left out as both had their
own hardware needs and also space limitations to be useful.
Then again when you can have a cpu to yourself neither multitask or multi-user was
high value save for foreground background multitasking as applied to printing
(print spoolers or printer managers).? ?The obvious reason for that is why sit and
wait for printer which had value.
Oddly the 1802 is one of the early cpus where foreground background and simple?
multi task management were both sensible and useful in real time control
applications.
Allison
