Answer: The Tandy TRS-80 Model I

Early computers lacked discrete sound cards/modules and often didn’t even sport a simple on-board PC speaker. That didn’t stop early PC enthusiasts from enjoying sound, however indirectly and unintentionally, with an early model personal computer.

The Tandy TRS-80 Model I was manufactured by the Tandy Corporation and sold by RadioShack from 1977 to 1981. Hobbyists quickly discovered that if you placed an AM-band radio next to the computer, it could be used to provide sounds. The sounds weren’t encoded into the programs or even an intentional feature included with the computer itself.

The Model I was so poorly shielded and generated such high levels of radio-frequency interference that placing a radio near the unit created quite an array of sound effects. The interference-driven sound effects clearly didn’t align themselves with most applications, but were a surprisingly good match for early space-based games.

Although the model was a popular one, ultimately selling over 200,000 units, it was removed from the market in 1981 due to aging hardware and stricter FCC regulations on radio-frequency interference that would require significant design changes.