os8088 1.0 Released: A Mac-like OS for IBM XT and 286/386 Systems

Introduction to os8088 1.0

os8088 1.0 is a newly released graphical operating system designed for Intel 8086/8088 processors, commonly found in original IBM PC and PC/XT machines. It presents a desktop environment reminiscent of the 1984 Macintosh System 1, featuring overlapping windows, pull-down menus, and support for a serial mouse. The entire system is written in real-mode assembly and boots directly from a floppy disk, without an underlying DOS environment.

Technical Specifications and Features

The operating system operates within 256KB of RAM and supports a 640x480 resolution with 16 colors. Its kernel is 52,718 bytes, and it includes pre-emptive multitasking with 12 task slots, preempting at 18.2Hz. Unlike the original Macintosh, os8088 incorporates pre-emptive multitasking, allowing multiple programs to run concurrently as first-class applications. The interface includes standard elements like draggable windows, menu bars, close/minimize boxes, and a dock for running programs.

Historical Context and Development

os8088 is a hobby project that re-imagines what a graphical OS for early IBM PCs could have been, drawing inspiration from the brief period when Digital Research's GEM 1.0 offered a similar desktop experience on the IBM PC before legal action from Apple led to its modification. This project, developed forty years later, provides a functional system that runs on period-accurate hardware, including the IBM 5150, Toshiba T1100 Plus, and 286 machines. The source code, comprising 66,183 lines of NASM, is publicly available.