Systems

TRS-80

Radio Shack's surprise success

The TRS-80 brought personal computing to Radio Shack stores across America, becoming an unexpected bestseller and establishing the home computer market.

home-computersamerican8-bit 1977–1991

Overview

Radio Shack expected to sell a few thousand TRS-80s to hobbyists. They sold 10,000 in the first month and 200,000 in the first year. The “Trash-80” (as critics called it) proved that personal computers could be mass-market products, sold in shopping malls rather than electronics stores.

Fast facts

  • Manufacturer: Tandy Corporation (Radio Shack).
  • Released: August 1977.
  • CPU: Zilog Z80 at 1.77 MHz.
  • RAM: 4KB expandable to 16KB (Model I).
  • Graphics: 128×48 “graphics” via block characters.
  • Sound: None (Model I).
  • Storage: Cassette, later floppy disk.
  • Price: $599.95 (including monitor).
  • Nickname: “Trash-80” (affectionately or not).

The 1977 trinity

Three machines defined 1977:

  • TRS-80: Cheapest, available everywhere.
  • Apple II: More capable, more expensive.
  • Commodore PET: Business-oriented all-in-one.

Radio Shack’s retail presence gave TRS-80 unmatched accessibility.

Distribution advantage

Radio Shack stores were everywhere:

  • Over 3,000 US locations in 1977.
  • Customers could see, touch, try computers.
  • Staff trained to demonstrate and support.
  • No mail-order uncertainty.

This accessibility drove early adoption.

Business applications

The TRS-80 found unexpected professional use:

  • Word processing: Electric Pencil, Scripsit.
  • Databases: Simple filing systems.
  • Small business: Affordable automation.
  • Before IBM PC: TRS-80 was the business standard.

Model evolution

The line expanded significantly:

  • Model I (1977): Original, massive success.
  • Model II (1979): Business-focused, 8-inch floppies.
  • Model III (1980): Integrated design, FCC compliant.
  • Model 4 (1983): Final Z80 model.
  • Color Computer (1980): Different architecture, consumer focus.

Software library

Despite limitations, software thrived:

  • Games: Scott Adams adventures, arcade ports.
  • Productivity: Word processors, spreadsheets.
  • Languages: BASIC, Pascal, C.
  • CP/M compatibility: Access to business software library.

Limitations

The Model I had notable weaknesses:

  • Graphics: Block characters only, no bitmap mode.
  • Sound: None without add-on hardware.
  • RF interference: Failed FCC certification, discontinued.
  • Keyboard: Mushy feel, questionable reliability.

The Trash-80 legacy

Critics mocked, but sales spoke:

  • First computer for many users.
  • Proved mass-market viability.
  • Established Z80 as standard processor.
  • Paved way for later home computers.

Legacy

The TRS-80 demonstrated that personal computers could be retail products. Radio Shack’s distribution network made computing accessible to people who’d never enter a computer store. The machine’s success surprised everyone—including Tandy—and proved the market existed.

See also