January 28, 2024 – New Manuals

Bill Allen has sent over a bunch of manuals for me to scan. The first set is below. Thank you, Bill!

Title: UltraDOS and SuperBASIC Reference Manual
Publisher: Vernon B Hester-Level IV Products
Year: 1980
Size: 205,822,671
Pages: 89
Notes: [2nd Printing]
Title: LDOS v5.1.x 1st Ed
Publisher: Logical Systems Inc
Year: 1982
Size: 751,777,287
Pages: 292
Notes: [Combined Model I and III]

January 23, 2024 – TRSTools / TRSRead

I have stumbled upon another disk format which TRSTools does not properly handle. I have tried to go through my old emails to find all the old reports, but many of them just sent disk images of which I no longer have records.

So … to those who use TRSTools and TRSREAD, please tread carefully on the following DOS image types:

  • MultiDOS double sided disks. TRSTools/TRSREAD will sometimes insert the side 2 data in the middle of side 1 files. I confirmed this by batch reading each disk double sided and then again as single sided, extracting the files, and comparing them. VDISK (by Miguel Dutra) extraction resulted in 100% identical crc’s between those sets. TRSREAD had multiple differences, where the Double Sided disk read was corrupt.
  • TRSDOS v2.3b disks.
  • DosPlus 3.4A for the Model III.
  • NEWDOS/80 images with damage on Track 1.
  • TRSDOS v2.77D, particularly deleting files, as they may corrupt the image.
  • TRSDOS 1.3 disks with extra data in a reserved area of the directory.

Right now, I have a slew of MultiDOS double sided disks (and CP/M double sided disks) where side 2 is inaccessible. The CP/M disks are entirely unusable; and that may be because they were made on a Model III with a Shuffleboard or because no tool exists to identify the geometry needed to mount them. The MultiDOS disks read (on a catweasel) as double-sided disks, but only Side 1 shows up in an emulator, and side 2 cannot be separately read as its own image.

January 16, 2024 – Model I ALPS Keyboard PCB

Marcel Erz has reverse engineered the Model I ALPS keyboard PCB. He says

This project is a faithful reimplementation of the ALPS keyboard PCB of the iconic TRS-80 Model 1 computer. My revision, the E1, is designed to replicate the PCB design 1-to-1 of the original down to the traces. The entire project is available under the MIT license.

Visit the GITHub Page for gerber files, Bill of Materials (CSV and PDF formats), layers exported in PDF and SVG formats, and full schematics of the E1 replica which is 1:1 to the original G board.

January 9, 2024 – Model 4 for sale Local Pickup in Texas

A site visitor has a working Model 4 (or at least drive :0 does) for sale for $300 for local pickup. Unit does have a loose connection in the plug at the power supply that powers the CRT filament, although most of the time the connection is good as is. Probably an easy fix. Drive 1 works when in Drive 0 position, so perhaps there is an issue with the controller or cable for the :1 position.

Seller is located about 100 miles NW of San Antonio, TX a few miles off of I-10; and could meet in or around Kerrville, Texas if that’s better.

If this sounds good, please reach out directly to Brick Parrish at .

January 3, 2024 – New Software Manuals thanks to Ian

Title: Flight Path
Publisher: Instant Software
Year: 1980
Size: 7,274,349
Pages: 7
Cat No: IS0171R
Notes: Contains Mountain
Pilot, Precision Approach Radar, and O’Hare
Title: DoSort Disk Sort Program v1.0
Publisher: Racet Computes
Year: 1979
Size: 12,836,790
Pages: 20
Title: Infinite Basic v1.0
Publisher: Racet Computes
Year: 1979
Size: 30,297,982
Pages: 46
Title: Night Flight Simulator
Publisher: George Day-Instant Software
Year: 1980
Size: 6,689,834
Pages: 7
Title: LazyFont
Publisher: Don Elmore-AlphaBit Communications
Year: 1983
Size: 46,983,177
Pages: 76
Notes: Set 1