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

The original sources of MS-DOS 1.25, 2.0, and 4.0 for reference purposes

A running-jumping-swordfighting game I made on the Apple II from 1985-89

📖 An approachable introduction to Assembly.

Virtual Apollo Guidance Computer (AGC) software

A cross-platform x86 assembler with an Intel-like syntax

Incompatible Timesharing System

BIOS for Intel 8088 based computers

sectorforth is a 16-bit x86 Forth that fits in a 512-byte boot sector.

Fully documented and annotated source code for Elite on the Nintendo Entertainment System (NES)

Microsoft BASIC for 6502 (Commodore, Apple, KIM-1, AIM-65, OSI, ...)

Historical source code for Infocom's Z-machine interpreters

bootBASIC is a BASIC language in 512 bytes of x86 machine code.

System Software for Z80/Z180/Z280 Computers

8-bit ATmega1284 retro computer

Minimal 68000-based single board computer

Program the esp32 ULP coprocessor in Arduino

Commodore 64 BASIC and KERNAL Source

Tiny assembler for 8086/8088, able to run over DOS for 8086/8088 machines.

A Basic (non Linux) C++ Kernel for Raspberry Pi.

Pinball Construction Set Source Code for Apple II

Microsoft BASIC for 6502 (Commodore, Apple, KIM-1, AIM-65, OSI, ...)

Z80 / 8080 / Z180 assembler (for unix-style OS)

Raspberry PI 8088 "hat"

Pi number calculator using 8088 assembly language

Schematics, design files, and software for my Ultim809 homebrew 8-bit computer.

Bootle (a Wordle clone in a x86 boot sector)

Disassembly of the Asteroids arcade game firmware

Simple Intel 8085 based Single Board Computer (SBC)