Original Apollo 11 Guidance Computer (AGC) source code for the command and lunar modules.

mal - Make a Lisp

Tetris that fits into the boot sector.

Computer implementation as described in "The Elements of Computing Systems"

Micro Kernel / Bootloader for Ben Eater's 6502 Computer

The Chip16 emulation project.

x86 assembler in 512 bytes of x86 machine code

Implementation of a general purpose computer and OS built from first principles.