Unearthing my 1996 windowed OS in machine code for Am29000 homebrew computer
4 hours ago
- The article describes the development of a windowed operating system for a homebrew Am29000 computer, written entirely in 32-bit machine code and bootable from a floppy disk.
- The author, Oscar Toledo G., created the OS between Fall 1996 and Spring 1997, drawing inspiration from OS/2 and X11R5 for window management and cooperative multitasking.
- Key challenges included writing an Am29000 emulator to run the OS, debugging instruction emulation (e.g., MULTIPLU, DIVIDU) and fixing a bug in the EXHWS instruction that caused file system corruption.
- The OS features a windowing system with message pipelines, rectangular clipping using XRegion, and services like video, keyboard, mouse, font, and filesystem management, all invoked via a custom interface.
- The final emulator, built with libSDL2, runs from two floppy disk images and includes programs like a text editor, debugger, color editor, and chess game, with support for printing and drag-and-drop file operations.