Your Chance to Build a New Sinclair ZX81
By James Grahame
I bought a Sinclair ZX80 computer by mail order when they were first advertised in BYTE magazine, unable to resist the bargain-basement price. These machines were cheap for a reason: The keyboard was printed on a large flat membrane, much like you'd see on a microwave oven. They had 1K of program memory and displayed B&W text on a TV set. Only crude character-based graphics, no sound.
The follow-up ZX81 featured an even simpler design with only four integrated circuits (some had an extra RAM chip, for a total of five), an RF modulator, and some discrete components. Because of its simplicity, Sinclair offered it as a kit for $99.95, or fully assembled for $149.95. Hundreds of thousands were sold, and I remember seeing it discounted to as little as $50.
Zebra Systems in New York still has a few original ZX81 kits for $99.95. They have thermal tape printers for $30, too. I'm not sure how many they have left in stock, but this is a great opportunity to build a seriously Retro piece of computing history.
New Sinclair ZX81 Computer kit (Zebra Systems)