Last Updated on April 4, 2026 by Dave Farquhar
When Radio Shack announced its TRS-80 Model 1 on Aug 3, 1977, designer Steve Leininger thought they could sell 50,000 units. Tandy executives didn’t believe him. But the response overwhelmed the company, and 250,000 people put their money where their mouth was, paying $100 to get on a waiting list to buy one.
At the time, the median price of a Radio Shack product was $30. A TRS-80 bundled with a CRT display and tape drive cost $599 and was the most expensive product they had ever sold.
The TRS-80 was the future
At the announcement, company president Lewis Kornfield said, “This device is inevitably in the future of everyone in the… world-—in some way-—now and so far as ahead as one can think.”
He got that part right, even if he was wrong about how many units they could sell. Kornfield had estimated the company could sell 3,000 units a year and John Roach decided to build 3,500 units initially because that’s how many company-owned Radio Shack stores existed in the United States at the time. If the computers didn’t sell, the stores could use them to track inventory.
Charles Tandy, who bought Radio Shack as damaged goods in 1962, was fine with building a small quantity of machines because of the publicity.
The timing was good because consumer demand for CB radios started declining in 1976. CB radios gained popularity as a result of the 1973 fuel crisis and institution of a national 55 MPH speed limit. Commercial drivers and even ordinary citizens used CB radios to track what stations had fuel and locations of speed traps. CB radio accounted for 20 percent of Radio Shack’s sales, and Radio Shack needed a high-end product to sell to replace them as demand faded.
The 1977 trinity
Three companies announced prebuilt computers and started selling them in 1977. The TRS 80 was the 3rd. Byte magazine called them the 1977 trinity. Both Apple and Commodore announced computers earlier in the year and took their first orders in June. There is a lot of controversy over which of the three was the first to sell a computer and which of the three sold the most. Apple said they sold their first machine June 10, 1977. Then after Chuck Peddle said Commodore sold its first unit June 5, 1977, Apple declared June 5 as “Apple II Day.”
Tandy was the last of the three to announce a machine and didn’t ship its first unit until September. But the limiting factor for all three companies wasn’t demand or consumer interest. All three companies had long waiting lists and couldn’t keep up with demand. They all sold their first computer faster than they could produce it and they all could have sold more than they did if only they had enough factory capacity to build more.
How many TRS-80 Model 1s sold
Radio Shack had an advantage because they already had an established dealer network of 3,500 stores and existing factory capacity capable of producing 18,000 computers per month. But even at that capacity, the TRS-80’s initial waiting list was more machines than Tandy could produce in a year.
Tandy ramped up production, sold 10,000 units in its first 45 days, 55,000 units in its first year, and a total of 200,000 units from 1977 to 1981. Even with the increased production, Tandy had a waiting list with a lead time of about two months until the summer of 1978.
In contrast, Commodore sold 500 PET 2001s in their first year. It’s all they could produce in 1977. As much as Tandy underestimated demand, Commodore underestimated it even more.
As far as how many units Apple sold in 1977, we don’t know. The October 1980 issue of Kilobaud Microcomputing estimated Tandy outsold Apple 3 to 1. It’s likely the number of Apple IIs sold in 1977 is closer to 18,000 than to the 500 units Commodore sold. But with Apple asking $1298 for just the system unit compared to $599 for the whole system from Radio Shack or Commodore, it’s little wonder Radio Shack sold more units.
An ecosystem sprung up around the TRS-80, including a popular computer magazine called 80micro.
The TRS-80 Model 1’s design
The TRS-80 Model 1 used a Zilog Z-80 CPU running at 1.774 MHz, and the number “80” in the machine’s name reflects that. The silver and black design came from RCA. RCA was the only company willing to sell a small quantity of 3,500 CRTs to Tandy. The cabinets they used were black and silver, so Tandy used the same color scheme on the rest of the computer.
The initial model had 4K of RAM, used a cassette tape recorder for storage, and had a 12-inch monochrome CRT, displaying 64 rows by 16 lines of text. It could only display uppercase characters. Leaving out support for lowercase lowered the cost of the system by $5. It had a full stroke keyboard and a single channel of square wave sound, similar to PC speaker sound. The TRS-80 had one more thing in common with the IBM PC. When IBM introduced its PC in 1981, they wanted it to be able to use a cassette recorder for storage, but IBM didn’t want to produce one. So they made the IBM PC compatible with the TRS-80’s cassette recorder, so interested consumers could buy the appropriate cable and recorder at any Radio Shack.
Although hobbyists often display and use them with a disk drive, initially all three 1977 computers used tape for storage. The 5.25-inch floppy disk drive wasn’t even invented until 1978 but all three systems rapidly adopted it.
David Farquhar is a computer security professional, entrepreneur, and author. He has written professionally about computers since 1991, so he was writing about retro computers when they were still new. He has been working in IT professionally since 1994 and has specialized in vulnerability management since 2013. He holds Security+ and CISSP certifications. Today he blogs five times a week, mostly about retro computers and retro gaming covering the time period from 1975 to 2000.
Way back in the day, my first paid computer job was a business system on Radio Shack equipment. Very limited memory. One of the guys I was working with realized video memory is still memory, so our sort process happened on the screen. Had to tell the customer to ignore the screen until it returned to a menu.