The TRS-80 Model I computer on a 1970s-colored background
Steven Stengel / Benj Edwards

45 years ago, Radio Shack released the TRS-80 Micro Computer System, a 1977 personal computer that launched an era of low-cost PCs along with computers from Apple and Commodore. Here’s what was special about it.

An Inexpensive, Ready-To-Use Computer

On August 3, 1977, Radio Shack introduced the TRS-80 Micro Computer System for $599.95—about $2,904 today adjusted for inflation. This complete system included a main unit with a built-in keyboard, a cassette recorder, and a monochrome monitor. After the introduction of the Model II later, this first model became known as the TRS-80 Model I. In 1977, the TRS-80’s $599.95 price was a big deal. To compare, the Apple II sold for $1298 with 4K of RAM (that’s a whopping $6284 today), and it didn’t include a monitor or a storage device.

The TRS-80 Micro Computer System in a Radio Shack catalog, 1977.
The TRS-80 as it appeared in a 1977 Radio Shack catalog. Radio Shack

But you always get what you pay for: The original TRS-80 was a fairly primitive machine. Under the hood, the TRS-80 utilized its Z-80 CPU at 1.77 MHz and included a mere 4 kilobytes (KB) of RAM. Its video could only display 64 columns and 16 rows of monochrome text (all uppercase) with no support for true bitmapped graphics (although by using a block-shaped text character, you could create a 128×48 pixel display). It also did not include any sound hardware, but many programs used a trick to output simple sounds through the cassette port.

A kid using a TRS-80 computer near a Christmas tree with its parents looking on.
Excerpt from a 1978 TRS-80 advertisement. Radio Shack

The TRS-80 gained its name as a combination of Radio Shack’s parent company (Tandy), Radio Shack itself, and its choice of CPU, the Zilog Z-80. Translate the name as “Tandy Radio Shack Z-80,” and it makes sense. Unfortunately for Radio Shack, the computer soon gained the derogatory nickname “Trash-80” because it was easier to say, and it had the extra bonus of a built-in put-down (that the computer was “trash” compared to machines like the Apple II). To this day, the Trash-80 nickname still bothers TRS-80 fans, so it’s not a kind or endearing name.

Despite its limitations, the Model I included enough features to delight many people who wanted to own their own ready-to-go computer system that they could use in the comfort of their home. While the “personal computer” as a concept was still a very new thing, many previous PCs were only available as kits. So to have a complete working computer at all (for $599.95) was something of a technological miracle at the time.

Part of an advertisement for the TRS-80 Model I that appeared in November 1977 issue of Byte magazine.
Radio Shack

Thanks to Radio Shack’s extensive network of 5,000 stores across the United States, the Model I was a huge hit from the beginning, selling 10,000 units in its first month and 100,000 units in 1978, which was a significant chunk of the young microcomputer market at the time. It inspired a loyal following that continued throughout the release of Radio Shack’s future PC systems over the next decade.

What Was It Like to Use a TRS-80?

When you purchased a TRS-80 Micro Computer System, you had everything you needed to write and store programs. The TRS-80 Model I included the BASIC programming language in ROM (and a very user-friendly manual), which allowed for relatively easy programming right out of the box. With the included cassette drive, you could load or save data to an ordinary audio cassette tape. If you bought an Expansion Interface and a floppy disk drive, you could save and load data much faster—but the combination of both units cost more than the original TRS-80 system.

A man using a TRS-80 on a desk. Part of an advertisement for the TRS-80 Model I that appeared in November 1977 issue of Byte magazine.
Radio Shack

You could also purchase software on cassette or floppy disk for your Model I computer. Popular applications included word processors like Scripsit and Electric Pencil, spreadsheet apps like VisiCalc, and games like Star Trek and Android Nim—not to mention text adventure games galore. In 1979, Leo Christopherson programmed a famous animated demo called The Dancing Demon, which quickly became the pride of many TRS-80 owners after Radio Shack published it.

Still, the TRS-80 has sort of a middling-to-lackluster reputation compared to other early PCs like the Apple II. We asked Harry McCracken—an editor at Fast Company and an early TRS-80 user—if the TRS-80 Model I was perhaps buggy or sub-par in his experience. He says that its lukewarm reputation is a misunderstanding, partially due to the computer’s nickname. “This whole retconning of ‘Trash-80’ as a supposedly fond nickname for a junky computer has misled people about what the TRS-80 was like,” says McCracken. “The TRS-80 didn’t have the glamour of the Apple II, but it sold better in the early days and was incredibly useful.”

RELATED: 45 Years Later, The Apple II Still Has Lessons to Teach Us

The TRS-80 Legacy

The TRS-80 Model I proved very popular, and it inspired at least 16 computers that carried the “TRS-80” brand name over the next decade. Of these, only the TRS-80 Model III and Model 4 series were backward-compatible with the Model I. The Model II started its own parallel branch, as did the TRS-80 Color Computer series. Here’s a list of the major TRS-80 models Radio Shack released over the years:

In 1984, Radio Shack began selling the Tandy 1000, which took its computer products on a very successful IBM PC-compatible branch. The “Tandy” brand took over full time on new PCs in 1985, including on some follow-up models of the TRS-80 line like the Tandy 102.

As for the TRS-80 Model I? After a successful 3 year run, Radio Shack stopped producing the Model I in January 1981 because it didn’t comply with new FCC rules. But it still had a huge impact and made a lot of fans along the way.

Happy Birthday, TRS-80!

RELATED: 40 Years Later: What Was it Like to Use an IBM PC in 1981?

Profile Photo for Benj Edwards Benj Edwards
Benj Edwards is an Associate Editor for How-To Geek. For over 15 years, he has written about technology and tech history for sites such as The Atlantic, Fast Company, PCMag, PCWorld, Macworld, Ars Technica, and Wired. In 2005, he created Vintage Computing and Gaming, a blog devoted to tech history. He also created The Culture of Tech podcast and regularly contributes to the Retronauts retrogaming podcast.
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