We’ve seen tiny microcontroller-based computers before, but nothing like this. Where the usual AVR + display + serial connection features BASIC, Forth, or another forgotten language from the annals of computer history, this project turns an AVR into a Lisp machine.

The μλ project is the product of several decades of playing with Lisp on the university mainframe, finding a Lisp interpreter for the 6800 in Byte, and writing a few lisp applications using the Macintosh Toolbox. While this experience gave the author a handle on Lisp running on memory-constrained systems, MicroLisp is running on an ATMega328 with 32k of Flash and 2k of RAM.  In that tiny space, this tiny computer can blink a few boards, write to an OLED display, and read a PS/2 keyboard.

The circuit is simple enough to fit on a breadboard, but the real trick here is the firmware. A large subset of Lisp is supported, as is analog and digitalRead, analog and digitalWrite, I2C, SPI, and a serial interface. It’s an amazing piece of work that’s just begging to be slapped together on a piece of perfboard, if only to have a pocket-sized Lisp machine.

Thanks [gir] for the tip.