Joystick Adapter for Model I

Pascal Holdry has reverse engineered the Model I Joystick Adapter which can be plugged directly into the output bus of the TRS-80 Model I via a 40 pin cable.

He advises it works with all games, via jumper select (Big 5 games need to be jumpered differently)

For more information visit his site. Note: There is a translation pulldown at the top of the right menu.

SDLTRS II Updated to v1.2.9

Site visitor lowen has let me know that Jens Guenther has updated his forked SDLTRS to v1.2.9.

Per Jens, this version runs on BSD, Haiku, Linux, MacOS(X), Solaris and Windows (95 to current).

Some of the updates include:

  • Fixed SDL2 regressions in version 1.2.8.
  • Added display of Z80 speed in window title bar.
  • Added “Turbo Paste” function.
  • Adjust Z80 clock rate on the fly.
  • Fixed bugs and other improvements.

New TRS-80 Trash Talk Podcast (Episode 35)

The podcast TRS-80 Trash Talk # 35 is out now.

“In this episode the Trash Talkers discuss the greatest TRS-80 rescue mission of all time as they head to Fort Worth to recover a significant TRS-80 collection. Then, we give you all sorts of ideas on what you can do with your TRS-80 while sequestered away in your home during the current global pandemic.”

You can download or listen at

New ROM Disassembly *and* Lance Micklus OK’s downloads

Two announcements:

  • Frank Durda IV had been working on a Model 4 ROM Update which was never released. That ROM has been disassembled and has been added to the ROM/CPU Page.
  • Thanks to a facebook discussion with Miyagami Noriko, I have corrected the entries for DOGSTAR ADVENTURE in the database and sought, and no have now received, permission from the awesome Lance Micklus to make all of his programs downloadable; so they are (and as programs are available, so are their manuals)! Thank you Lance!

TRS80GP v2.3 Released

TRS80GP has been updated to v2.3

Visit The TRS80GP Web Page for the download and information, or here for the emulator.

New Features:

  • Support for hard drives.
  • Model 16 emulation.
  • Preliminary support for Model I Percom and Radio Shack double-density disk interfaces.
  • Model II double-sided floppy support.
  • New Model II ROM now the default; get original with “-r0”.
  • Added Model 1 revision 1.1 ROM and -nlc not needed for earlier ROM revisions.
  • Emulator tries adding .dmk, .imd, .jv3, .jv1 and .dsk to files it can’t find.
  • Windows menu key brings up the right-click context menu.
  • Current drive track is displayed status bar.
  • Permit writing to Model I, III, and 4P ROM

Bug Fixes/Adjustments:

  • Montezuma CP/M no longer misses shift keys regularly.
  • If a disk FORMAT proceeds beyond the last track, DMK and IMD append blank tracks.
  • DMK format detection rules relaxed to allow for larger file truncation.
  • No longer get down-arrow stuck when using Ctrl+Alt+V and the like.
  • Debugger memory, disassembly and stack update on reset or change in memory map.
  • Cassette auto-save capture Scott Adams Adventures saves one instead of two files.
  • Animated GIF output usually smaller by extending the delay for repeated frames.
  • Debugger now shows Model II ROM contents and disassembly when it is mapped in.
  • Single stepping in debugger updates the trace window even if tracing is off.

March 4, 2020 – Site News

Site Updates since the last …