MOD Format Technical
Module file structure
The MOD file format stores sample data and pattern sequences in a self-contained file, enabling portable tracker music across platforms.
Overview
MOD files package everything needed for music playback: digitised samples and pattern data describing when to play them. The format originated with SoundTracker on Amiga and became the de facto standard for tracker music. Its simplicity enabled cross-platform players, while extensions (S3M, XM, IT) added features while maintaining the core concept.
Fast facts
- Origin: SoundTracker (Amiga, 1987).
- Contents: samples + patterns + sequence data.
- Channels: four in original MOD; more in extensions.
- Extensions: S3M, XM, IT added channels and features.
- Playback: player calculates audio from data.
File structure
What a MOD contains:
- Header: song name, sample info.
- Samples: digitised instrument sounds (8-bit).
- Pattern data: note, sample, effect per row per channel.
- Sequence: order patterns play in.
Extended formats
Beyond basic MOD:
- S3M: Scream Tracker, more channels.
- XM: FastTracker II, envelopes.
- IT: Impulse Tracker, most features.
- Modern: legacy formats still supported.