Date   : Mon, 28 Mar 1988 13:29:19 EDT
From   : <SAGE@LL.ARPA>
Subject: Clarification on ZCPR33 and Z System

Dave Goodman posted a message recommending ZCPR33 as the CP/M upgrade
of choice.  As the author of that code, I wholeheartedly concur. 
There were some statements made in that message, however, that I would
like to correct and/or amplify.
 
>> Z33 is public domain; you will find it on a number of RCPM's (Remote
>> CP/M System) around the country, or, you can buy it from Echelon, Inc.
>> (at a modest cost) in either an auto-install version, which works on
>> most, but not all, systems, or a manual install version (which makes
>> for a more versatile installation).  To do the manual installation,
>> you will need a working knowlege of the insides of cp/m, and some
>> modest ability with z80 assembly language.  I believe you will also
>> need the ZAS assembler, also available at modest cost from Echelon.
 
First, Z33 is NOT really public domain; it is copyrighted by me and by
Echelon.  However, there is no royalty charge for personal
(noncommercial) use.  For that use it is distributed on many remote
access computer systems, including my own Z-Node.  There is a license
fee for use of Z33 with a commercial product.
 
Second, the autoinstall versions of Z System (combined ZCPR and ZRDOS)
that are about to be released (NZCOM for CP/M 2.2 systems and Z3Plus
for CP/M 3 systems) are far MORE VERSATILE than a manual installation,
as well as being completely automatic.  It is true that there are some
computers on which they will not work (though not very many, and on
some of those it is very hard to get a manually installed version to
work either), but when they do work you get a system in which the
operating system features (and corresponding operating system size)
can be varied dynamically to meet your requirements, on a permanent
basis or on a command-by-command basis.  For normal operation you can
have a complete Z System with all the bells and whistles at a cost of
about 6K of TPA space.  But when you need to run a memory-hungry
program, the operating system can be made to shrink (all the way
back to plain CP/M if desired) to provide the extra memory and then
expand again when that application has completed.
 
The main difficulty encountered with these systems is that some
configuration utility programs provided by the computer manufacturer
that work by performing absolute modifications to data in the BIOS
often will not work properly under NZCOM or Z3Plus.  Those utilities
can be fixed, if necessary.  Usually, however, they are used only
rarely, and you can shut off the automatic Z System long enough to use
them.  I will be speaking at the Trenton Computer Fair on these new
systems.  They will include, by the way, version 3.4 of ZCPR, which
includes a number of interesting and useful new features.  Z34 will
not be made available over remote systems; it will be available only
as a commercial product but at a very modest cost.
 
-- Jay Sage