Using a Modern Day Hardware In Lieu of Real TRS-80 Parts


There are a number of solutions, hardware and software, which will allow modern day hardware to function as a replacement for original TRS-80 hardware, or to otherwise help it along. This could take the form of having the PC act as a fake cassette player, fake disk drive, emulated floppy/hard drive (attachable to a real TRS-80) and the like. Currently, there exists modern hardware or solutions to replace the following TRS-80 parts: Monitor, floppy drive, cassette player, hard drive, and Model I power supply. The below are some of those solutions:

Using a Composite Monitor In Lieu of a Model I Monitor

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The TRS-80 was originally sold with a 13″ RCA Black and White Television with most of the guts ripped out. However, there can be times that a monitor is not available, you can build this cable to connect your Model I to a composite monitor. For instructions, visit here.

TRS-80 Model I Hard Disk Adapter Board

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TRS-80 Model I’s require an adapter board to adapt the 40-pin connector on the Model I Expansion Interface to a 50-pin connector for hard drives.

Since these boards are virtually impossible to find today, Ian Mavric has created an adapter board, so those with Model I’s can connect to a real TRS-80 hard drive or, eventually, a FreHD Hard Drive emulator.

The cost for the fully-assembled board (including the TRSHD15/DCT and TRSFRM15/CMD drivers) is be $50.00 + Shipping. For those without the Hard Drive cable, cables are also available for purchase for $40.

The ideal system is a 48K Model I Disk system (in good condition) running LDOS v5.3.1 with a TRS-80 5MB or 15MB Hard Drive.

The board is NOT YET compatible with the FreHD system.

Contact Ian on

TRS-80 Hard Drive Emulator

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The FreHD is an external card which can be plugged directly into a TRS-80 to emulate a TRS-80 hard drive.

More information can be found on the Modern Drive Replacements for REAL TRS-80’s page.

Building a Replacement Model I Power Supply

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It is very common today for people to have Model I power supply issues. While common wisdom says to cut open non-working supplies and check/replace the fuse, sometimes that is not possible, that is not the problem, or the individual is missing a supply altogether. Dean Bear has designed a replacement power supply for the Model I. For instructions, visit here.

Case for Expansion Interface

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If you have an Expansion Interface but no case, Andrew Quinn is offering this perspex “case”, which he advises is strong enough to support the monitor.

The cost is NZ$25 and you can reach him at jaquinn2001 at gmail dotcom.

Using a PC In Lieu of a Cassette Recorder

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Knut Roll-Lund has written a utility called PlayCAS which allows for the use of a PC as a cassette player for a TRS-80 Model I/III/4 Level I and II.

You simply connect your TRS-80 cassette input to your PC soundcard (if using a standard TRS-80 cable plug the plug that normally goes into the ‘Ear’ output of a CCR-8x into the PC’s headphone jack). When you then run the PLAYCAS utility, you can CLOAD (or SYSTEM) on the TRS-80 and feed it an emulated CAS file.

PLAYCAS supports 250 Baud (Level I), 500 Baud (Level II), and 1500 Baud (Model III) and supports SYSTEM (Machine Language), CLOAD/CSAVE (Level II BASIC), EDTASM (Editor Assembler), and Level I BASIC and Machine Language.

Using a PC In Lieu of a Disk Drive

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Eric Rothfus has developed a hardware device called the SVD (Semi-Virtual Diskette) which is a device which emulates a floppy drive.

Using an Add-In Card In Lieu of a Disk Drive

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The HxC Universal Floppy Disk Drive Emulator designed by Jean-Francois Del Nero, emulates a 34 pin floppy drive and treats DSK and DMK images which are stored on a SD card as actually floppy disks. To be clear, this product is designed to be mounted in/on an actual TRS-80, as a drive on the floppy cable.

Using a PC To Make/Read TRS-80 Disks

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Jens Schoenfeld, through his company Individual Computers, has developed a floppy disk controller, called the Catweasel, which is designed to allow computers with PCI slots to read/write a variety of disk formats, including the TRS-80 Model I, III, and 4.

The Catweasel cannot read or write TRS-80 disks on its own. Tim Mann, author of the XTRS emulator, wrote a set of tools which would allow the Catweasel to read and write the TRS-80 formats. His utilities include cw2dmk to read a real diskette into DMK file, dmk2cw to write a DMK file onto a real diskette, and two utilities dmk2jv3 and jv2dmk to convert between DMK format and JV1/3 format.

One thought to “Using a Modern Day Hardware In Lieu of Real TRS-80 Parts”

  1. Do you know of any boot programs, or any program that would allow a modern day p/c to use a TRS-80 DW2 printer, I have multi part forms that I would like to print on.

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