Date   : Wed, 23 Mar 1988 10:55:00 EST
From   : RLH <HAAR%gmr.com@RELAY.CS.NET>
Subject: CPM/M 3.0 vs. 2.2

Phillip Keen recently questioned the advantages of upgrading to
CP/M Plus (3.0) over 2.2 . Since Lee Thomison spoke (typed?) out in
favor of version 2.2, I thought I would add my views in the
other direction.

I have been using version 3.0 for about three years and would not
switch back to 2.2 for any reason. I run an S-100 bus system with
192K of RAM.

advantages of 3.0:

       - supports banked memory
       - put much of the system in bank 0, TPA in bank 1
       - increase TPA space ( 48K to 60K in my system)
       - allows BIOS additions without decreasing TPA space
       - time/date stamping of files
       - disk buffering in banked memory
       - cleaner command set (in my opinion)
       - residnet system extensions (RSXs) allow loadable
         device rivers, system extensions, etc. much like
         TSR's in MS-DOS.

I must admit that everything is not wondeful. I use a CCP replacement
call CCP+ to have an improved shell and a SideKick-like utility
called Write-Hand-Man. Many of the advantages above have been
implemented in other ways my various manufacturers or PD software
writers, but not in any standard fashion.

CP/M 2.2 is the standard work-horse version. If you don't have extra
memory or don't want the features made possible in 3.0 by memory
banking, switching to 3.0 isn't worth much.

ZCPR3 provides a nicer environment than either one. I bought ZCPR3.3
and tried it out. But I decided to stay with CP/M 3.0 because the
disk caching and larger TPA made lot's of stuff faster. There is 
supposed to be a version of ZCPR coming out this spring that runs
on CP/M 3.0. This desires some attention. I may go that route myself.

Ther have been some complaints of incompatibilities between CP/M
version 2.2 and 3.0 . I run many commercial programs written for
2.2 with no problems. The only place I have seen any is with
some PD software that goes to the BIOS directly or makes assumptions
about the file structures beyond what is provided at the BDOS
level. SD is the only program I use that had this problem and it was
fixed in later versions. There is also something called 22RSX
that claims to provide complete version 2.2 compatiblity if you need
it. I haven't had call to use it, so cannot comment.

For me CP/M 3.0 is the way to go. For anyone else - make up your
own minds. But first ask yourself what you want the system to do
and what is important to you.

               Bob Haar
               
               HAAR@GMR.COM    ( CSNET or ARPANET)