TRS-80 Hardware Upgrades / Replacements

About this page!

The TRS-80 community is still very active, especially in the hardware department. Many people have developed either new upgrades, or revese engineered old upgrades, and all of these are available for purchase or self-build.

These can take the form of upgrades in terms of storage (emulate floppy drives or hard drives with SD cards or USB), replicated hardware (RS-232, power supplies, ORCH-80, Hi-Res), or even completely new functionality (Wifi, printer access).

There's no great way to try to get all of this on one page, so this page is more of a link list. All links point to pages on this site, which give more explanations and external links. This just minimizes the work for when sites go down.

Page Index

Storage Related Memory Related Power Keyboard / Video Multi-Function Expansion Communications and Internet Misc Stuff Online Stores

Storage Related

Floppy Drives and Controllers


Gotek

A Gotek drive replacement allows vintage computers or equipment to use USB storage in place of traditional floppy disks by emulating a floppy drive with modern flash media. More information can be found HERE.

Floppy-80 Floppy Disk Replacement

For those with a Model III or Model 4 (Non-Gate-Array Model) but no floppy drive controller, this card is designed to completely replace internal and external floppy disk drives by using a single SD card for storage, enabling systems without floppy controllers to function without original floppy disks. It cannot be used alongside real floppy drives.

Click for more detail

Floppy-80 Board

For those out there with a Model III or Model 4 (NGA), Patrick Bureau of Texas Tandy Restorations is selling a hardware board called the Floppy-80.

The Floppy-80 is designed to replace entirely internal drives and external drives with a single SD card. It cannot be used in conjunction with real floppy drives, but can be used in systems that do not have floppy controllers.

The Floppy-80 board plugs directly unto the motherboard 20 pin edge connector that normally be used to connect a flat ribbon cable to the floppy disk controller (and +5v from a molex) that will let you mount DMK disk images (or HFE as read-only) on the fly on drives :0 :1 :2 and :3 and use the images as if they were real diskettes inserted into your TRS-80. .ini files can be prepared to set the 4 drives to a preconfigured configuration.

One of the other main features/benefits of the Floppy-80 is that you can set up .INI files which populate the drives, and can switch between those .INI files on the fly. You can also designate an .INI file which will be the default.

A utility for use in the TRS-80 is included and allows for the following additional commands:

CommandMeaning
STAGet the Floppy Drive Controller status, including displaying all mounted DMK images
DIRDisplay a directory of the root folder of the SD Card to show what DMK files are available to you for mounting
INISelect a INI file to be the default
MNTMount a disk image
IMPImport a file from the SD Card
EXPExport a file to the SD Card

An example of the commands would be that if you type FDC MNT OS-M3-MULTIDOS-531.DMK 2 at your TRS-80 DOS prompt, the DMK file OS-M3-MULTIDOS-531.DMK will then be mounted as :2

The Floppy-80 supports the following DOS's for Drive 0

Model 3

TRSDOS v1.3
TRSDOS v1.5
LDOS v5.31
NEWDOS/80 v2.0
DOSPLUS v3.50
MULTIDOS v1.7
Z'DOS v1.0

Model 4 NGA

TRSDOS v6.21
LDOS v6.31
CP/M v2.2
DOSPLUS 4
MULTIDOS v5.00
NEWDOS/90 v2.0

The Floppy-80 board is sold both as a kit and fully assembled and tested - reach out to TexasTandyRestorations@gmail.com for info.

HxC Floppy Disk Replacement

The HxC Floppy Disk Emulator is a versatile electronic device that fully replaces a floppy disk drive by emulating its behavior, supporting a wide variety of floppy disk formats and systems; it uses SD card or USB storage to read and write floppy disk images and can emulate two floppy drives at once.

Click for more detail

HxC Floppy Emulator

The SDCard HxC Floppy 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.

It can emulate one or two drives, and disk images are mounted using the three buttons on the lower right, which are NEXT, SELECT/EJECT, and PREVIOUS. The filenames are shown on the LCD, which comes in a variety of colors.

Current features of the SDCard HxC Floppy Emulator are:

  • Modes Supported: Shugart and PC
  • Two floppy disk drives emulation
  • 5V +/- 10% standard power floppy connector input
  • 3 LEDs ("Power LED","Floppy access LED"," SDCard access LED ")
  • 3 buttons ("Next","Select/Eject","Previous")
  • 1 audio transducer
  • 2*16 chars Alphanumerical LCD (LCD and buttons can be put on an external front panel)
  • SD Card up to 2GB / SDHC Card supported up to 32GB
  • FAT32 supported. Subdirectory and long name file supported
  • Track mode based floppy emulator (Full track pre-encoded in the HFE image file)
  • Write support: ISO MFM 256/512/1024 Bytes sector write supported, ISO FM/SD 128/256/512/1024 Bytes sector write supported.
  • Bitrate support: 250/300Kbits/s (DD floppies), 500Kbits/s (HD floppies)
  • RPM support: 300, 360
  • Tracks / Side support: Up to 256 tracks per floppy, 1 or 2 sides.

The documentation can be found here and the changelog can be found here.

Floppy Drive Remapper

A board (and microcontroller) which dynamically remaps the floppy disk drives in Model III/4 computers to swap between the internal and external drives.

Click for more detail

Floppy Drive Remapper

Floppy Drive Remapper for the Model III/4/4D/4P by George Hines

After installation, a switch will allow booting from (and use) external floppy drives as though they were placed internally. This is a convenient way to use a floppy drive emulator or a real floppy (interchangeably) without having to retrofit the case or swap cables each time.

More information can be found at https://github.com/mrthreeplates/TRS-80_floppy_remapper

They are also sometimes available for sale at Tuc's Workbench

Hard Drives and Controllers


TRS-80 Model I Hard Disk Adapter Board

A Model I adapter board, so those with Model I's can connect to a real TRS-80 hard drive or a FreHD Hard Drive emulator. More information can be found HERE.

Lo-tech TRS-80 IDE Adapter rev.2

an external storage adapter designed for Tandy TRS-80 Model 3, 4, and 4P computers that enables the connection of standard IDE hard drives or compact flash cards, allowing a TRS-80 to use modern storage devices for data access and booting More information can be found HERE.

FreHD

A a hard drive emulator for TRS-80 Model I, III, and 4 computers that uses an SD card to simulate a hard drive, allowing vintage systems to bypass traditional floppy drives and gain faster, more reliable storage; it appears to require a ROM update for the system to boot from it and can support multiple virtual hard drives via disk images stored on the SD card. More information can be found HERE.

Feet

For those with Original hard drives which may be missing feet, these are a comparable substitute. More information can be found HERE.

Badges

For those with Original hard drives which may be missing badges, you can buy them here. More information can be found HERE.

Memory Related

Model I and III


X-MEM/80

A 512 KB paged memory expansion for the TRS-80 Model I and Model III which is entirely external.

Click for more detail

X-MEM/80 for Model I

Model I Version

X-MEM/80 for Model III

Model III Version

Michael Wessel and Mark Pruden have developed X-MEM/80, a 512 KB paged memory expansion for the TRS-80 Model 1 and Model III.

According to them:

No permanent modifications are required for installation. The Model 1 version is entirely external (via expansion port edge connector), and the Model III version simply plugs into the existing Z80 socket on the Model III motherboard - the CPU needs to be relocated from the Model III motherboard onto the X-MEM/80 board, but it is already socketed. No motherboard modifications are required, but the RF shielding in the Model III needs to be removed.
Unlike previous memory expansions for the Model I (i.e., SuperMem), this is a minimally invasive memory expansion that does not require any soldering for installlation.
X-MMEM/80 is partially SuperMem compatible, as it allows to "bank" the upper 32 KBs (address range from 0x8000 to 0xFFFF) with the memory on the card.
A jumper allows configuration in two different modes - SuperMem and X-MEM/80 modes:

More info can be found at: https://github.com/lambdamikel/x-mem-80

Power

Model I

Dusty's Vintage Workshop sells pre-built Model I power supply replacements on their ebay store.

For those who prefer to build their own, Marcel Erz has provided gerbers, boms, schematics, and instructions.

Model III

NewSoft sells power supplies which use modern components. You can see them on the Newsoft page.

Newsoft also sells a replacement power plug assemby which will allow you to use modern computer plugs in your Model III.

Keyboard / Video

Model I

To use a composite monitor instead of the standard TRS-80 monitor, you can build this cable to allow for that. It is also possible that the cable can be bought from Tuc's Workbench

Model III

Jay Crutti has designed a full Model III keyboard replacement. You can get more information at https://www.jaycrutti.com/hardware-projects/tandy-trs-80-replacement-keyboards

Model III / 4


NEWKEY/80 Ultra

The NEWKEY/80 Ultra, by Plaid Vest Software, will allow you to use an external Keyboard and Joystick with a TRS-80 Model III or Model 4.

Click for more detail

Newkey Ultra Board

The USB Keyboard and Joystick Adapter for TRS-80 Model III/4.

Compatibility

  • TRS80 Model 3 or 4

Why NEWKEY/80 Ultra?

  • Replace your broken or poorly functioning keyboard
  • More familiar PC keyboard layout
  • Play games using an Atari Joystick!
  • Accurate key response with no ghosting or keybounce
  • Multi-key shortcuts for DOS functions (DFG, JKL, etc.)
  • Multi-key mode for advanced key handling
  • Use your favorite USB keyboard (wired or wireless) on your TRS-80

Features

  • Compatible with most standard USB keyboards
  • Also works with wireless 2.4Ghz USB keyboards
  • Atari-compatible 9-pin joystick port
  • Compact size. Mounts inside TRS-80 case.
  • Can work simultaneously with existing keyboard
  • Fast and accurate key response without keybounce or ghost characters
  • Native TRS-80 key repeat
  • Handles special keys independently (arrows, space, control, break, shift, @) for excellent compatibility
  • Works great with games and applications
  • Supports TRS80 control and multi-key sequences
  • Easily upgradable firmware to allow for enhancements and bug fixes

Notes

  • NEWKEY/80 Ultra mounts inside the TRS80 case. This is a fairly easy process but does require +5v and ground connections. A 4-pin Molex Disk Drive power splitter cable and a plain 2-wire power connector are included.
  • Wireless keyboards need to be the "no drivers required" 2.4Ghz type
  • A USB keyboard extension cable (not included) can be used to route the keyboard connector outside of the TRS80 case (not needed when using a wireless keyboard).
  • A common 9-pin D-Sub or Atari joystick extension cable (not included) can be used in a similar fashion to route the joystick connector outside of the TRS80 case.

Visit https://www.plaidvest.com/newkey80.html for more details and for ordering.

BLUE-PRINT

The BLUE-PRINT TRS-80 Composite Video Board is a composite video mixer board combines the video signals of a TRS-80 Model II, III, 4 or 4P computer into a monochrome composite video signal. They are for sale at Tuc's Workbench.

Click for more detail

BluePrint

The BLUE-PRINT TRS-80 Composite Video Board is a video mixer board designed for Tandy Radio Shack TRS-80 models such as the Model II, III, 4, and 4P. It converts the original video signals from these TRS-80 computers into a monochrome composite video signal, allowing connection to modern composite video monitors or TVs. This board generates a monochrome or green composite signal with no color information, making it compatible with both NTSC (American) and PAL (European) standards.

More information can be found at https://blue-print.be/.

They can sometimes be found for sale at Tuc's Workbench.

In Development

Matt Boytim is working on a small board which will permit using a PS2 keyboard and/or a VGA or HDMI monitor on a Model III or Model 4. The work-in-progress GITHIB can be found here

Model 4


High-Res Graphics

Ian Mavric has developed a High-Res Graphics board for the TRS-80 Model 4/4GA/4D. It is compatible with the microlabs GX 4.2 board and can be ordered for the cost of $179.99 plus shipping.

Click for more detail

https://youtu.be/2zckRx-I7y4

More information can be found at http://www.frehd.com.

Multi-Function Expansion

Model I


The M1SE v1.2

An add-on device for the Model I which connects to the buffered expansion port on the Expansion Interface or directly to the Model I keyboard. It offers myriad functionality including: boot from SD, ethernet, clock/calendar, SVGA output, Joystick port, and ROM extensions for hard drives, clocks, and double-density.

Click for more detail

MISE System Expander

The MISE (Model I System Expander) is an add-on device for the vintage Radio Shack TRS-80 Model I microcomputer. It connects to the buffered expansion port on the Expansion Interface or directly to the Model I keyboard, and provides these benefits:

  • Direct-booting solid state hard disks on Compact Flash, with LDOS-5.3.1 preloaded. No boot floppy or ROM modification is required. Each bootable image can hold up to 64MB, and multiple images on CF cards are supported. That's a whole lot of space for programs mostly written for 16KB RAM. Dual CF cards can be used for additional storage or easy backup.
  • 10/100 Mbps wired Ethernet connection (up to 8 active IP sockets) with included software: FTP and TFTP servers, FTP client, DHCP client, SNTP client, Telnet client, and Telnet server and DNS client demo programs. Globally-unique MAC address (EUI) provided. Easily move files to and from your TRS-80! Drag and drop!
  • Real-time clock/calendar with battery backup, compatible with the vintage Alpha Products Newclock-80. Battery backup means the date and time will be accurate and automatically set at every system boot.
  • Crystal-clear SVGA display output for an 800x600 @ 60Hz monitor, no software required. One-of-eight selectable foreground, background, and border colors. Emulation of the vintage high-resolution PCG-80 and 80-Grafix devices. 80-column text display mode available. Using the VGA display is optional; you can still use the original CRT monitor if you prefer, or you can even use both at the same time.
  • ROM extension including drivers for the hard disks, real-time-clock, and double-density floppy adapter, if you have one. None of these drivers need consume precious high memory.
  • Joystick port for Atari 2600 compatible joysticks. Works with most vintage Model I games.
  • 256-byte general purpose Flash EEPROM for persistent storage.
  • Last updated March 26, 2019.

The manual, set-up instructions, software, and far more information (including ordering) can be found at http://bartlettlabs.com/MISE/.

MXS: TRS-80 Modular eXpansion System

A stackable modular hardware system for the TRS-80 Model I computer that starts with a base module providing 32K memory expansion and power, and can be expanded with additional modules such as a floppy drive emulator, a Texas Instruments video/graphics board, and a WiFi board; the modules connect via headers carrying address, data, interrupt, and wait signals, enabling flexible hardware expansion and communication with the TRS-80 through a port I/O system rather than memory mapping.

Click for more detail

MXS System

The TRS-80 Modular eXpansion System (MXS) designed by Jay Rounceville, consists of up to four modules set up as a stackable set, starting with the base module which will give you a 32K and supplies the power that the other boards use. On top of this you can add the floppy drive emulator module. Other modules include a Texas Instruments video/graphics board and/or a WIFI board.

Schematics and overview can be found at https://github.com/calphool/TRS80MXS.

Model III / 4


The M3SE v1.1

An add-on device for the Model III which connects to the expansion port on a Model III and Model 4. It offers similar functionality to the M1SE.

Click for more detail

M3SE System Expander

The M3SE (Model III System Expander) is an add-on device for the vintage Radio Shack TRS-80 Model III, Model 4, Model 4D, and Model 4P microcomputers. It connects to the buffered expansion port, and provides these benefits:

  • Solid state hard disks on Compact Flash, with LDOS-5.3.1 and LS-DOS 6.3.1 preloaded. An included boot floppy is required except for the TRS-80 Model 4P, which auto-boots from the hard drives. Each bootable image can hold up to 64MB, and multiple images on CF cards are supported. Dual CF cards can be used for additional storage or easy backup.
  • 10/100 Mbps wired Ethernet connection (up to 8 active IP sockets) with included software: FTP and TFTP servers, FTP client, DHCP client, SNTP client, Telnet client, and Telnet server and DNS client demo programs. Globally-unique MAC address (EUI) provided. Easily move files to and from your TRS-80! Drag and drop!
  • Real-time clock/calendar with battery backup, compatible with the vintage Alpha Products Newclock-80. Battery backup means the date and time will be accurate and automatically set at every system boot.
  • Crystal-clear text-only SVGA display output for an 800x600 @ 60Hz monitor. 80-column text display mode available. Using the VGA display is optional; you can still use the original CRT monitor if you prefer.
  • Joystick port for Atari 2600 compatible joysticks. Works with most vintage joystick-enabled games.
  • 256-byte general purpose Flash EEPROM for persistent storage.
  • Works with both "slow" (2MHz) and "fast" (4MHz) CPU clock rates.
  • Last updated September 27, 2018.

The manual, set-up instructions, software, and far more information (including ordering) can be found at http://bartlettlabs.com/M3SE/.

Communications and Internet

All TRS-80 Models


NEWPRINT/Multi

A Wi-Fi-enabled "virtual" printer adapter that connects to your computer's printer port and your local Wi-Fi network to send printer output to any device that supports a modern browser. Has a web interface.

Click for more detail

NEWPRINT/Multi Board

The NEWPRINT/Multi is a Virtual Wi-Fi printer with web-browser output for all TRS-80 models.

Requirements

  • Wi-Fi requires a 2.4Ghz network. 5Ghz is not supported
  • Power adapter (+5v DC) USB-C or standard barrel connector

Limitations

  • TRS-80 is text only

Details

  • NEWPRINT/Multi is a Wi-Fi-enabled "virtual" printer adapter that connects to your computer's printer port and your local Wi-Fi network to send printer output to any device that supports a modern browser (iPad, Desktop PC, Mac, etc.).
  • The NEWPRINT web interface can show printer output as plain text, hexadecimal values, Print Shop graphics (Apple II), or Apple IIgs GS/OS graphics printing.
  • Text mode output does not (currently) understand special printer control codes used by most word processors (BOLD, multiple font sizes, Form Feed, etc.).
  • The NEWPRINT web interface is available from any browser on your local Wi-Fi network at newprint.local
  • NEWPRINT uses the standard HTML WebSocket API so you can even write your own web-based or desktop interface for displaying and processing NEWPRINT output.
  • Note: A power adapter (+5v DC) and printed User's Manual are not included to keep prices low. See the PDF User's Manual below for more information.

Visit https://www.plaidvest.com/newprint.html for more details and for ordering.

Model I


The 26-1145 RS-232 interface

A modern reproduction of the RS-232 board which fits inside a standard Expansion Interface. More information can be found HERE.

Click for more detail

RS-232 Interface Board

Roger Murley / BYTESHiFT has developed a recreation of the 26-1145 RS-232 interface board for the Model I

They are available for sale to those who wish to purchase one, or for those who like to build, the Gerbers, schematics, BOM, and KiCAD source files are available on GitHub.

Roger's design replicates the operation of the original board, ensuring compatibility with existing Model I software. Hardware-wise, he reports a few differences:

  • SMT components are used wherever possible, to minimize cost
  • Sense switch (DIP switch configuration) functionality is removed, so that the interface must be configured via software
  • The TERM/COMM switch has been removed. The unit is configured in TERM (DTE) mode, and an external null-modem adapter must be used if operation as a DCE device is required.
  • IC selection eliminated the need for +12/-12/-5 supply rails. +5V is the only supply needed

More info can be found at: https://byteshiftmusic.com/trs-80-model-i-rs-232-interface-re-creation/

Model III / 4


TRSNIC

TRSNIC is a WiFi TCP/IP network interface for the Model III and Model 4.

The TRSNIC provides the foundational protocols required to implement existing network interactions on the TRS-80 microcomputer. The first such protocol provided is TCP/IP via an implementation of the Berekely Sockets API. TCP/IP is the dominant low level network protocol in use today. Many of today's higher level network protocols like HTTP and FTP are implemented on top of TCP/IP. This means many modern networking systems can be built upon the base TCP/IP support provided by trsnic.

Details can be found at this GITHUB

TRS-IO

The TRS-IO a 48K TRS-80 Model III online capabilities and provides access to a variety of internet shares including the RetroStore, access to files mounted on a SMB share, and access to remote servers via TCP.

Click for more detail

TRS-IO Architecture

TRS-IO gives a 48K TRS-80 Model III online capabilities and provides access to a variety of services. TRS-IO currently features the following capabilities:

  • Access to the RetroStore
  • FreHD emulation - Not to be used in conjunction with FreHD
  • Access to files mounted on a SMB share
  • Access to remote servers via TCP

Information on the TRS-IO can be found at https://github.com/apuder/TRS-IO.

Misc Stuff


Talker/80

A new Voice Synthesizer for the Model I, III, and 4

Click for more detail

Talker/80 attached to Model I

Attached to Model I

Talker/80 Model I Board

Model I Board

Talker/80 Model III/4 Board

Model III/4 Board

Michael Wessel has developed the Talker/80, a new Voice Synthesizer for the Model I, III, and 4. It has natural sounding speak (like Alexa), requires no machine language driver, and has an E/I passthrough so it will work with a E/I, FreHD, and Quinterface.

The Talker/80 emulates the TRS-80 Voice Synthesizer and the VS-100.

The Talker/80 is open source under the GPL3 License and is maker-friendly (no surface mount soldering and easy to acquire parts). See:

Orchestra-85 for the Model I

The Orchestra-85 Music Addon Board Reproduction by Ian Mavric.

Click for more detail

Orchestra-85

A stereo music synthesiser with up to six octaves, 5 simultaneous notes (or voices), each of which can be assigned any of five instrumental choices (tone colour registers). Plays old /ORC music files.

More information can be found at http://www.frehd.com.

Orchestra-90 for the Model III/4

The Orchestra-90 Music Addon Board Reproduction by Ian Mavric.

Click for more detail

Orchestra-90

A stereo music synthesiser with up to six octaves, 5 simultaneous notes (or voices), each of which can be assigned any of five instrumental choices (tone colour registers). Plays old /ORC music files.

More information can be found at http://www.frehd.com.

Badges

NewSoft sells replacement badges for all types of TRS-80. You can find them on the Newsoft page.

Feet

For those with missing Model III/4 feet, you can try the EVERBILT 1001-687-347 Rubber Bumpers (be very careful about screw length).

Online Stores

There are a number of stores where very reputable people offer various TRS-80 related products.

Newsoft - https://jaynewirth.wixsite.com/newsoft

Case badges, Model III/4 power supplies, Drive sleds (FreHD, Gotek, Blank) with and without drives, Power assembly replacement.

Tuc's Workbench - https://shop.tucs-workbench.com/

Basically ... everything. Chips (ROMs, RAM, Character Generators), Cassette drive belts, Capacitor kits, lower case kits, EPROM Adapters, PIC controllers, Floppy Remapper, MFMemu, Power supplies, XMEM/80, TRS-IO, LNDoubler, Blue-Print TRS-80 Video Board ...

The Right Stuff - https://www.trs-80.com.au/

FreHD Hard Drive Emulator, Hi-Res Graphics for Model III/4/4P/4D, Chips (Z80, 4116, 4164, 41464, FD1771), Lowercase kits for the Model I, Model I Double Density Adapter, Model I Serial Adapter Cable, Buffered EI Cable, FreHD/Quinnterface Combo, FreHD/M1HD I/F Combo, "Quinnterface" Mini Expansion Interface for 16K Model I, U72 GAL (PAL-compatible) chip for M4 128K upgrade, Model 1 Hard Drive Adapter, Power Supply for TRS-80 Model I, Composite video cable for Model I, CP 40W Power Supply for TRS-80 Model III and external secondary Hard Drive, Inter-connect cable for TRS-80 III/4 Hard Drive, ASTEC 65W Power Supply for TRS-80 Model 4/4P/4D/Hard Drive