Hardware
There was a great deal of add-on hardware available for the TRS-80. Radio Shack sold “official” hardware products in their catalog and stores. Many hobbyists developed their own hardware projects, which were often published in newsletters and magazines. Third-party companies sold add-on hardware, and some of this hardware became more popular than the Radio Shack equivalents.
The Model III to 4 Upgrade Kit
Mayday Uninterruptable Power Supplies
The Radio Shack Model 4 High-Resolution Board
The Radio Shack Model III High-Resolution Board
The FASTLOAD Cassette Interface
The Holmes Expansion Mainframe
The Radio Shack Double-Density Disk Kit
The Stickeroo Joystick Interface
The Electric Pencil Lower Case Modification
The Lobo LX-80 Expansion Interface
The Micromint Disk-80 Expansion Interface
The Mikrokolor Color Graphics Interface
The Radio Shack “expansion box”
The Radio Shack Expansion Interface
