New Model I/III Diagnostic ROM

Kevin Trojanowski has let me know that Adrian Black has introduced a Model I/III diagnostic ROM to help in troubleshooting Model I/III systems.

The ROM can be downloaded from his Github page.

Paul Thomas Metcalf III mentions that you do not need the adapter board which Adrian mentions if you use a TMS2516 EPROM. Unlike a 2764 or a 27128, the TMS2516 is pin compatible with the ROM socket.

SDLTRS II Updated to v1.2.24

Jens Guenther has updated his fork of the SDLTRS Emulator to version 1.2.24. Changelog includes:


  • Added 6845 CRTC Interlace Mode Emulation.
  • Added VideoExtension HRG for EACA EG 3200 Genie III.
  • Added Genieplus Memory Card for EACA EG 3200 Genie III.
  • Added character set for Meritum I (Mera-Elzab).


  • Fixed Virtual Keyboard for SDL2.
  • Fixed more bugs and other improvements.

You can download the most recent SDLTRS II from the Gitlab page:

Fixed Error on Ports and I/O Devices Page

Site visitor Leonardo Brondani Schenkel correctly pointed out that I had listed Bit 5 of Port 0ECH as being for the Model 4 only on the Ports and I/O Devices page. It is also used on the Model III. On both models, this bit controls video waits. George Phillips was kind enough to explain why the bit is actually not used (only set once) in the ROM, and the page has been updated to cover that as well.

Thank you for the eagle eye, Leonardo, and thank you George, as always.

New Service Manuals

August 20, 2022 – New Service Manuals

Patrick and Matt have provided some missing Service Manuals. They can be downloaded by clicking on the covers, or from the Service Manual Download Page.

Thank you Patrick and Matt

Model III Disk Modification Kit [Set 1]
Year: 1980
Company: Tandy
Size: 413MB

Model III Disk Modification Kit [Set 2]
Year: 1980
Company: Tandy
Size: 227MB

Model III Service Manual
Year: 1980
Company: Tandy
Size: 7.5MB

FP-215 Flat Bed Plotter Service Manual
Year: 1982
Company: Tandy
Note: 26-1193
Size: 28MB

MxZVM Infocom Executor Updated

Shawn Sijnstra has updated his INFOCOM EXECUTOR for the Model I and the Model III to v5 and for the Model 4 to v15.

Changes Include:

  • Core code rewrites for speed in : parsing var/1op/2op, encode dispatch, objects, attribute, properties, text buffer, stream3 [M1/3/4]
  • Code rewrite for tracking exceptions/errors [M1/3/4]
  • Front end rewrite for speed in: cursor, text wrap, cache mem [M1/3/4]
  • Increased cache size by 3 sectors [M1/3/4]
  • Bugfix: timer routine fixed and scaled for M1/M3 interrupt differences [M1/3]
  • Bugfix: transcript support now works [M1/3]
  • Enhancement: extra space allows for Border Zone and Shogun [M1/3]
  • Bugfix: transcript now properly honours change to the transcript bit [M4]
  • Change: accented characters now filtered out in transcript [M4]

You can get the source and executables from the respective GitHub pages of and and


Kyle Wadsten has announced that he is stopping production of his NEWKEY/80 and NEWPRINT/MULTI products.

He writes:

Just a short announcement that I am shutting down production of my NEWKEY80 and NEWPRINT/Multi products.
There are a number of reasons for this but it mostly relates to time, costs, and parts availability issues.
I am proud to have been able to provide some “new life” to many TRS-80 owners over the last few years. What started as one-off devices for myself turned into a sometimes-crazy building/fulfilment process that I didn’t really expect.
I do have a couple NEWKEY80/DUO-JOY and NEWPRINT/Multi units left so if you were having any thoughts of purchasing then now would be the time.
Finally, a huge **thank you** to all of my past customers for their purchases and kind words.

Thank you Kyle for your wonderful contribution to the TRS-80 community!