This repository is a complete, commented disassembly of Sonic the Hedgehog 2 for the Sega Genesis/Mega Drive. It provides the full 68000 assembly source code for the game, including the Z80 sound driver, level data, art mappings, music and sound effect definitions, and a build system that can reassemble a bit-perfect ROM. The project is the result of extensive reverse engineering and documents the game's memory layout, object system, and hardware interactions in detail. The architecture is organized as a collection of assembly source files, with a Lua-based build script (build.lua) that orchestrates assembly via the AS macro assembler, compresses music and sound data using the included Saxman/Kosinski compression tools, and patches the final ROM. Precompiled native binaries for the assembler and compression utilities are provided for Windows, Linux, macOS, and Android, ensuring cross-platform reproducibility. The codebase makes heavy use of macros for code generation, data definition, and hardware abstraction, which improves maintainability and readability. It supports multiple ROM revisions (REV00, REV01, REV02) and includes optional bug fixes and optimizations that can be toggled at build time. The repository also integrates with the SonLVL level editor through INI and XML object definitions. Key reusable components include the ClownLZSS compression library (supporting Kosinski, Saxman, and Kosinski+ algorithms), the SMPS sound conversion macros for music data, and the sprite mapping macro system. These can be extracted and applied to other Sega Genesis projects or any project requiring similar compression or sound driver conversion.
RunCPM is a Z80 CPU and CP/M emulator that executes unmodified 8-bit CP/M application binaries on desktop operating systems and embedded microcontrollers. The code provides a complete Z80 instruction-set emulation (selectable among four CPU models), a CP/M 2.2/3 BDOS and BIOS dispatcher, a built-in CCP console command processor, and a host-directory-to-CP/M-drive mapping. Desktop entry points are RunCPM/main.c; embedded entry points are in RunCPM/RunCPM.ino, with board-specific hardware definitions for Arduino, Teensy, ESP32, STM32, and RP2040. CP/M disk drives are folders on the host filesystem, and user areas are numbered subdirectories. External dependencies are limited to platform C libraries, optional SDL/RunVT terminal integration, and SD-card filesystem support on embedded targets. Custom BDOS calls allow CP/M programs to control physical GPIO pins on supported boards.