Subj : Re: BBSing on CP/M
To   : Dr. What
From : acn
Date : Mon Sep 20 2021 15:39:00

Am 18.09.21 schrieb Dr. What@21:1/194 in FSX_RETRO:

Hallo Dr.,

ac>> There was MP/M, the multi-user CP/M OS. It supported different users
ac>> on terminals on a Z80.

DW> Ooo..  I forgot about that.  Do you happen to know how widespread MP/M
DW> got? I've never actually seen a computer that ran it.

Sorry, I don't have numbers or more information on that.
Have a look at the Z80 scene, eg. in the Google Group "retro-comp" :)
There, some people are running MP/M on some machines.

ac>> And there was Concurrent CP/M on x86, I guess it also supported
ac>> virtual terminals and multitasking.

DW> I've started looking into CP/M-86, but I didn't know that Concurrent made
DW> their own version.  Intersting.  Something more for me to research.

"Concurrent CP/M" is still from Digital Research, as I've read on  
Wikipedia (.de), Concurrent CP/M-86 is a later version of MP/M-86 +  
CP/M-86.

ac>> But the bare CP/M did not support multitasking, neither on Z80 nor on
ac>> x86.

DW> I know that there was a program called Double Duty for the TRS-80 line.
DW> It let you load 2 programs into memory and swap between them.  But I think
DW> that was the most the Z80 could do along the idea of "multitasking".

Don't underestimate the Z80 :)
There are some UNIX derivatives like FUZIX, which allows multitasking.
And there is even a multitasking OS with a GUI called SymbOS, which  
runs on some Z80 machines. Pretty amazing :)

Regards,
Anna

--- OpenXP 5.0.50
 * Origin: Imzadi Box Point (21:3/127.1)

.