Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!hplabs!hpda!hpcupt1!hprnd!jahr
From: jahr@hprnd.HP.COM (Steve Jahr)
Newsgroups: comp.os.cpm
Subject: Re: modern Z80 operating systems (beyond CP/M)
Message-ID: <3150004@hprnd.HP.COM>
Date: 8 Jun 89 22:20:46 GMT
References: <918@auvax.AthabascaU.CA>
Organization: HP Roseville Networks Division
Lines: 32

Of those you mentioned, my favorite is TurboDos.

This particular CP/M look-alike supported full blown multi-tasking,
print spooling, networking, disk cache buffering, and came in a neat
package.

One of the more interesting architectures implemented was all of the
various S-100 multiprocessor systems.  These systems used a seperate
slave processor with it's own CPU/memory/io "networked" across the
bus to a master processor that did io server duties.

If you have a choice get a 1.41 or later version as these versions
supported banked memory: a user program bank and a system bank of
almost 64k each.  With this option you could get one of the largest
TPAs available.  Otherwise all of the nice features take up memory
and limit the TPA.

One nice feature of Turbo was that all commands were written as 
programs, there are no "built-in" commands.  The command processor
was only a program loader.

I could go on and on but to implement this wonder you will need the
Turbo Implementors Guide, be comfortable/have with assembler, and
go for it.  The os resides in normal disk files, so you could bootstrap
with CP/M and then go for Turbo.  Also the *whole* OS is packaged as
a *bunch* of relocatable "REL" files.  A nice link and patch facility
is provided so adding new drivers in is a breeze!

Well have fun...

Steve "a Turbo GURU in a past life" Jahr
(916) 785-4275