gw-basic-2026/docs/index.md

GW-BASIC 2026

A portable C reimplementation of Microsoft GW-BASIC, using the original 8088 assembly source (released by Microsoft in 2020) as the authoritative reference.

This is not a transpilation — it reimplements the algorithms in clean C11 with modern data structures while targeting bug-compatible behavior. Unlike the original assembly (43,771 lines across 43 .ASM files), this version is structured as modular C suitable for new feature development.

Highlights

• Authentic full-screen editor — dynamically sized screen buffer (25×80 default, full terminal with --full), free cursor movement, Enter-on-any-line, F1-F10 function keys, Insert/Overwrite toggle
• Binary and ASCII file formats — SAVE writes tokenized binary by default, LOAD auto-detects format (just like the real thing)
• INKEY$ extended keys — arrow keys, F-keys, and navigation keys return proper CHR$(0) + scan code two-byte sequences
• Sixel graphics — SCREEN 1/SCREEN 2 rendering in compatible terminals
• Sound — SOUND, BEEP, PLAY (MML) via PulseAudio, plus continuous tone via OUT (8253 PIT / PPI speaker emulation)
• Hardware I/O — OUT, INP, WAIT port emulation (PIT, PPI, CGA, COM1, game port) for classic programs that drive hardware directly
• Full file I/O — sequential, random-access, SAVE/LOAD/MERGE/CHAIN/COMMON
• Printer output — LPRINT/LLIST to file or real hardware via --lpt
• Classic programs — Hamurabi, Lunar Lander, Gunner, and Diamond from David Ahl's BASIC Computer Games (1978) run out of the box
• 70 test programs with golden-file regression testing and DOSBox-X compatibility testing against real GWBASIC.EXE
• MIT License

:maxdepth: 2

getting-started
language-reference
architecture
development
roadmap