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TRS-80

technology Maturity 11-13 Next article →

The TRS-80 was a special desktop microcomputer.

Radio Shack Tandy TRS-80 Model I System
Radio Shack Tandy TRS-80 Model I System

It was made by the Tandy Corporation. They sold it in their Radio Shack stores. This machine was one of the first home computers sold to many people.

Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)
Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)

It helped change how people used technology at home. Many people called it the "Trash-80" as a joke.

Radio Shack Tandy TRS-80 Model I Rear Panel
Radio Shack Tandy TRS-80 Model I Rear Panel

Later, the company called it the Model I to be clear. It was a very important tool for small businesses and schools.

The computer worked using a Zilog Z80 8-bit microprocessor.

Radio Shack Tandy TRS-80 Model I PCB
Radio Shack Tandy TRS-80 Model I PCB

This is the tiny part that acts like the brain. It used 4 KB of DRAM for its memory.

Radio Shack Tandy TRS-80 Model I Keyboard
Radio Shack Tandy TRS-80 Model I Keyboard

The system had a full QWERTY keyboard for typing. It also had a screen that showed 64 characters in each line. To save programs, people used a cassette tape drive.

TRS-80-graphics
TRS-80-graphics

The computer used a language called BASIC to run tasks. This language helped the machine understand instructions from the user. Users could even add more memory later to make it stronger.

Designing the TRS-80 was a big project for Tandy.

Radio Shack Tandy TRS-80 Model I Keyboard
Radio Shack Tandy TRS-80 Model I Keyboard

A man named Don French saw a computer kit and got an idea. He worked with John V. Roach to plan the machine. They hired a man named Steve Leininger to help with the technical parts.

Radio Shack Tandy TRS-80 Model I PCB
Radio Shack Tandy TRS-80 Model I PCB

Leininger wanted to sell a preassembled computer instead of a kit. He thought many people would find it hard to solder parts together. In February 1977, they showed a prototype to Charles Tandy. The first test even crashed when typing a large salary! They fixed it by adding better math support to the BASIC language.

The TRS-80 launched at a press conference in New York City.

Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)
Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)

It cost $600 for the basic system. You could get a monitor and tape recorder for more.

Radio Shack Tandy TRS-80 Model I System
Radio Shack Tandy TRS-80 Model I System

People were very excited and many joined a waiting list. By 1979, it had the largest selection of software available. It was so successful that it outsold the Apple II by five times.

Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)
Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)

Over 200,000 units were sold during its lifetime.

This computer was part of the "1977 Trinity" of machines.

Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)
Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image)

This group included the Apple II and the Commodore PET. The TRS-80 was easy to find because of Radio Shack stores.

Radio Shack Tandy TRS-80 Model I System
Radio Shack Tandy TRS-80 Model I System

These stores were in many small towns across the country. Later, Tandy made the Model III and the Model 4.

TRS-80 Model 4 (modified)
TRS-80 Model 4 (modified)

These new models were compatible with the older ones. The TRS-80 name eventually became a brand for many different computers. It helped lead the way to the computers we use today.

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🖼️ Images & Media (10)
File:Radio Shack Tandy TRS-80 Model I System.JPG
Radio Shack Tandy TRS-80 Model I System.JPG
File:Home or Personal Computers from 1977 - Commodore PET 2001, Apple II, TRS-80 Model I, together called 'Trinity77' (edited image).jpg
Home or Personal Computers from 1977 -...
File:Radio Shack Tandy TRS-80 Model I PCB.JPG
Radio Shack Tandy TRS-80 Model I PCB.JPG
File:Radio Shack Tandy TRS-80 Model I Rear Panel.JPG
Radio Shack Tandy TRS-80 Model I Rear Panel.JPG
File:Radio Shack Tandy TRS-80 Model I Level II ROM Upgrade PCB.JPG
Radio Shack Tandy TRS-80 Model I Level II...
File:Radio Shack Tandy TRS-80 Model I Keyboard.JPG
Radio Shack Tandy TRS-80 Model I Keyboard.JPG
File:TRS-80-graphics.svg
TRS-80-graphics.svg
File:TRS-80 Model 4 (modified).jpg
TRS-80 Model 4 (modified).jpg
File:TRS-80 Model 4P Crop Delsener.jpg
TRS-80 Model 4P Crop Delsener.jpg
File:DGT-100 Brazilian TRS-80 Clone.jpg
DGT-100 Brazilian TRS-80 Clone.jpg
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