README.tpm
Tim Mann <tim@tim-mann.org>
1/12/98

As computer scientists, we always long for something bigger and better
than what we have now.  Give us a megabyte, and we want a gigabyte.
Give us an emulated TRS-80 Model I with Level II BASIC and cassette,
and we long for the Expansion Interface and floppy disk drives.  Give
us that, and we want a Model III.  Give us a Model III, and we want a
Model 4!

This is a snapshot of the work I've been doing on xtrs to add these
niceties.  My main additions over xtrs-1.0 have been floppy disk and
hard disk emulation, timer interrupt emulation, a kludge to import and
export data to the host system, Model III mode, Model 4 mode, a
rewrite of the keyboard handling, support for most of the undocumented
Z-80 instructions, and a bunch of bug fixes and minor improvements.

This project has been a real (48KB?) trip down memory lane for me.  I
worked as a programmer for Logical Systems, the company that produced
LDOS, during 1980-81 before I went to grad school.  I no longer own a
TRS-80, but I recently found a box in my storage closet containing all
my Model I hardware manuals, schematics, ROM disassemblies, and even
the assembly listing for a version of the LDOS Percom Doubler driver
that I helped write, giving me enough information to get my additions
to xtrs off the ground.

Since then I've done much more. Check out my TRS-80 Web page at
http://www.tim-mann.org/trs80.html for details!
