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From: towson%amsaa@sri-unix.UUCP
Newsgroups: net.micro
Subject: Re:  TRS-80 Model III CP/M?
Message-ID: <15352@sri-arpa.UUCP>
Date: Mon, 9-Jan-84 11:34:23 EST
Article-I.D.: sri-arpa.15352
Posted: Mon Jan  9 11:34:23 1984
Date-Received: Sun, 15-Jan-84 05:52:39 EST
Lines: 22

From:      David Towson (CSD) <towson@amsaa>

David - The TRS-80 Models I and III can run "remapped CP/M" with a transient
program area beginning at 4300H instead of 0100H (the standard location).
Lifeboat Associates has (or at least had) such a version of CP/M, and FMG
Corporation (still in business?) did too.  Some Heath computers also use this
arrangement, so if you cannot find a TRS-80 version for sale, you can probably
hack the Heath bios to work on a TRS-80.  At least two companies, Omikron and
Memory Merchant, sell memory remappers that shift read/write memory down to
location-zero, thereby allowing the use of standard CP/M.  The last price I
heard was $130 for the Omikron device plus CP/M.  The same companies also offer
two options for dealing with the TRS-80 ROM.  The remapping rolls ROM up to
address C000H (in a 48K system).  The Omikron system (I don't know about the 
other) overlays part of the TRS-80 ROM address space with their own ROM which
contains the system initialization code and part of the bios.  You can just
ignore the remainder of the ROM address space and write it off, or you can get
a RAM board that is addressed to that area, making that address space usable.
If you cannot find a source of "remapped CP/M", but you wish to go that way,
contact me again and I'll try to help.

Dave Towson
towson@amsaa