Amethyst: 8-Bit Home Computer, Powered By An AVR Microcontroller

Published at : 23 Dec 2025

An ATmega1284-based computer with color video, sound, built-in mechanical keyboard, and Forth interpreter in ROM. This is the first in a series of videos I'll be uploading about this project. It gives a high-level overview of the project and demonstrates its capabilities.

Video captured from a RetroTINK 2x upscaler: https://www.retrotink.com/product-page/retrotink-2x

The Mandelbrot renderer was based on this Apple II BASIC code snippet: https://github.com/bradgrantham/apple2a/blob/master/examples/mandelbrot.bas

Source code and schematics are on GitHub, but as of 1/7/20 there isn't much in the way of documentation or instructions. https://github.com/74hc595/Amethyst

Follow me on Twitter: http://twitter.com/txsector

(Before anyone asks about my 6809 computer project: it's been inactive and I probably won't return to it anytime soon. Sorry! Too many other things to do!)