The Coleco Adam? A not-so-great home computer that likely contributed to the downfall of the company. The keyboard, however, is a different story, and worth repurposing.

[Nick Bild] has created a USB adapter that uses a Teensy 4.1 and an RJ-12 breakout board. Now this wasn’t just a simple matrix to decode. No, the fine folks at Coleco rolled their own communications protocol called AdamNet.

The keyboard uses an RJ-12 connector and a single data line to communicate over a 62.5 kbit/s, half-duplex serial bus. Inside the keyboard is a Motorola 6801 that caches the key presses and sends them to the computer. So the BOM is limited to what you see above — an RJ-12 breakout and a Teensy 4.1. It’s great to see old keyboards come alive again, especially one with such cool sci-fi keycaps. Want to hear it clack? Of course you do.

Continue reading “Keebin’ With Kristina: The One With The Duplex Typewriter” →