Date   : Mon, 14 Dec 1987 10:55:21 PST
From   : bridger%rcc@rand-unix.ARPA
Subject: Re: CP/M Plus, Banked ZRDOS, Z280 

1. Z280:
Scott Moore at Zedux, 818-787-0113 voice, 818-787-0458 bbs has a Z280
board running with a multi-tasking OS he supplies with it.  It
supports multiple cp/m partitions, but not zcpr3.

2. Z3ON3 -- the port of ZCPR33 to CP/M 3 (CP/M PLUS) that is under
development -- will provide essentially all ZCPR3 features on a CP/M 3
system, including:

       z3 external environment descriptor
       zcpr33 command processor
       flow control (FCP)
       resident command processor (RCP),
       z3 termcap
       z3 named directories
       but NOT: input/output packages (IOP).

Most CP/M 3 features remain active:
       hashed directories
       bdos disk buffering
       RSX capability, including PUT/GET redirection

There are some changes:
       multiple command line is zcpr3 style
       file-level passwords not supported by the command processor

Importantly, no bios changes are required -- Z3ON3 will be a "drop-in"
RSX; the user will install and remove "ZCPR33" features from a cp/m 3
system dynamically, with one command.


3. Echelon developed a banked version of ZRDOS for the DT-42, with a
cp/m 2.2 bios.  I don't believe any other banked versions have been
developed.  Trying to do one for a CP/M 3 bios would be problematic
at best, because CP/M 3 makes fundamental changes in the bios/bdos
disk i/o interface.

--bridger