RadioShack's parent unveils a $399 computer; skeptics inside the company called it unsellable

CB radio sales were fading, and Tandy Corporation, the leather-and-electronics retailer behind RadioShack, needed a new product to fill 3,000 stores. On August 3, 1977, at a press conference in New York City, Tandy announced the TRS-80: a Zilog Z80 machine with 4 KB of RAM, a full keyboard, and a cassette drive, priced at $399, or $599 bundled with a monitor and tape recorder. Company executives had spent months insisting computers wouldn't sell. Tandy planned to build only 3,500 units to start; within the first month and a half, more than 10,000 had sold…