xtrs is a Radio Shack TRS-80 Model I/III/4/4P
emulator for Unix and the X Window System. It includes lower case,
the real time clock, hi-res graphics, serial port, parallel printer,
mouse, cassette, sound and music output (requires OSS), 5" and 8"
floppy disk drives in single and double density, and even hard disk
drives. The emulated floppy and hard disk file formats are compatible
with the popular MSDOS-based emulators by Jeff Vavasour, Matthew Reed,
and David Keil, and (if you choose a capable enough file format), all
features of the original TRS-80 floppy disk controller are
emulated. Under Linux, physical floppy disk drives are also
supported. Physical cassettes can be read and written too. The user
interface is a bit spartan, but it gets the job done.
Alternatively, you may prefer
the sdltrs TRS-80
emulator maintainted by Jens Guenther (originally written by Mark
Grebe). sdltrs is a TRS-80 emulator for Linux, Mac
OS X, and Windows, with a nice GUI front end that uses the
cross-platform SDL library, and a back end that originally derived
from xtrs. It has a menu UI that makes it easier to change settings
and insert/remove emulated floppy disks and tapes, as well as several
back end features that xtrs doesn't have.
xtrs downloads and resources
- xtrs is now
hosted on GitHub. At this writing, compared with the very
old xtrs 4.9d release that I formerly distributed on this
page, the GitHub version includes an optional GTK GUI version
called gxtrs (spartan but usable), emulation of the Exatron
Stringy Floppy, code and documentation patches from several
contributors, and a few other fixes and cleanups.
- ROM images for Model I/III/4 are available elsewhere on the Web.
I do not know the copyright status of these ROM images, and I have
no connection with the sites that offer them.
Some MS-DOS based TRS-80
emulators come with Model I and Model III/4 ROM image files.
These files will work in xtrs too. (However, the pseudo Model 4P ROM in
David Keil's emulator works only with that emulator, not with xtrs.)
- Alternatively, for Model III or Model 4 emulation, xtrs can use a
MODELA/III file as its ROM image. This is not identical to a real
Model III/4 ROM, but is close enough that almost 100% of TRS-80
programs will work with it. The LS-DOS
6.3.1H operating system disk that I have permission to
distribute includes a MODELA/III file. You can boot this operating
system using xtrs's Model 4P emulation and export the file for use
in Model III and 4 emulation, or for
convenience, click here to download
the MODELA/III file directly.
- For Model 4P emulation, you can use Pete Cervasio's free minimal
xtrs Model 4P boot ROM.
This ROM can boot only Model 4 operating systems (not
Model III), and only from floppy disks. The original Model 4P boot
ROM is copyrighted software, but if you own a Model 4P, you can copy
its boot ROM onto a floppy for personal use using the instructions
and tools in this article,
originally published in the Misosys Quarterly 1.2, and it will work
with xtrs as well.
- Technical documentation is available for the emulated floppy disk file formats used
by xtrs and other popular TRS-80 emulators.
- The original xtrs 1.0 was
written by David Gingold and Alec
Wolman; see their README file.
It emulates a Model I with cassette, 48KB of memory, and
an uppercase-only display.
If you are writing your own emulator, you are welcome to use my
code, in whole or as a guideline. The copyright on the original xtrs
code also permits such use. I would appreciate receiving a copy of
any improvements you make to the code, however, so that we can release
a better xtrs in the future when time permits.
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