Information about Module File

Module files (MODs) have several different file formats. One important format is that of the Fortran Module, which is a compiled "intermediate" file like the object files compiled from Fortran source code. A more popular Module file represents music on a computer, and the following paragraphs are limited to discussions of this music file format.

Module files store several patterns or pages of music data in a form similar to that of a spreadsheet. These patterns contain note numbers, instrument numbers, and controller messages. The number of notes that can be played simultaneously depends on how many tracks there are per pattern.

Module files also give a list of the order in which to play the patterns. However, the biggest advantage of MOD family over standard MIDI files is that MODs include their own audio samples and should sound exactly the same from one player to another (barring interpolation methods and any errors in players).

Module files are often referred to as tracker modules, and composing modules is known as tracking, simply because the first ever module creating program was Ultimate Soundtracker, created by Karsten Obarski in 1987. Soundtracker was cloned many times, with programs such as NoiseTracker and ProTracker being direct descendants from the original Soundtracker code, and others such as MED/OctaMED and Oktalyzer being written from scratch. Such programs are called trackers in general. In 1990s world-wide usage of these programs led to creation of the so-called MOD-scene which was considered part of the Demoscene.

Popular formats

Each format builds on concepts introduced in its predecessors.

Sound/Pro/Noisetracker module (file extension .mod) (suffixes usually substituting prefixes outside of Amiga systems)

The format that started it all. Uses inverse-frequency note numbers. 4 voices, up to 32 in later variations of the format. Pattern data is not packed. Instruments are simple volume levels; samples and instruments correspond one-to-one. 15 instruments in the original Soundtracker, 31 in later trackers. This format was originally created to be easily playable with the Amiga hardware, since it was equipped with a four-channel DAC. The CPU has to do very little work to play these modules on an Amiga. Many games utilize this format - with possibly cut down replayers - and not only on the Amiga platform, either.

The original .mod extension is actually not a suffix on the Amiga, but a prefix; mod.* is the standard naming convention on the Amiga, and same prefix standard is used in basically all the other various sample/synth-trackers ever made for the Amiga - Art of Noise, AHX/THX, Musicline, Startrekker, FutureComposer, SidMon, Brian Postma's SoundMon etc. The majority of the "oldschool format"-players for Windows, Linux, Mac OS etc. will, when trying to load an "original" mod.*-file (or ahx.*, bp.*, fc14.* and so on), simply not play it due not analysing the file to determine the type - they only check for a filename extension as a suffix.

Oktalyzer (originated on Amiga computers)

This was an early effort to bring 8 channel sound to the Amiga. Later replayers have improved on the sound quality attainable from these modules by more demanding mixing technologies.

MED/OctaMED (originated on Amiga computers)

This format is very similar to sound/pro/noisetracker, but the way the data is stored is different. MED was not a direct clone of SoundTracker, and had different features and file formats. OctaMED was an 8-channel version of MED, which eventually evolved into OctaMED Soundstudio (which offers 128-channel sound, optional synth sounds, MIDI support and lots of other high-end features).

AHX (originated on Amiga computers)

This format is a synth-tracker. That is, there are no samples in the module file, rather descriptions of how to synthesize the required sound. This results in very small audio files (AHX modules are typically 1k-4k in size), and a very characteristic sound. AHX is designed to sound as much like a Commodore 64 as possible.

.s3m (originated in ScreamTracker version 3 for PC)

Up to 16 or more voices. Samples can specify any playback frequency for middle C. Simple run-length packing of pattern data. Introduction of several new controllers and a dedicated "volume column" in each voice to replace volume controllers. Predictable support for stereo panning.

.xm (originated in Fast Tracker)

Introduction of instruments with volume and panning envelopes. Basic sample compression.

.it (originated in Impulse Tracker; not to be confused with the country code for Italy)

New Note Actions let the previous note in a track fade out on top of the next note (providing greater effective polyphony). Instruments can now share a sample. Adds some new effects such as a resonant filter. Better sample compression.

.ned (Nerd Tracker II)

Designed for playback on Nintendo Entertainment System. No samples in basic format (just tone generator instrument specification); extended format uses compressed samples but limits playback frequencies to the 16 rates that the NES hardware is capable of reproducing. Each channel has its own order list.

Software module file players and converters

Mac OS X

• CocoModX
• PlayerPro (also for Mac classic)
• XimpleMOD

Windows

• Winamp
• dbPowerAmp
• Deliplayer
• KbMedia Player (in Japanese)
• The KMPlayer
• Mod4Win
• ModPlug Player
• XMPlay
• Passion Audio Player
• Sonique
• VLC

DOS

• Dual Module Player (DMP)
• Inertia Player
• MikMod
• Visual Player

Linux/UNIX

• Amarok
• MikMod
• modplugplay
• Open Cubic Player
• Universal Module Player (UModPlayer)
• Unix Amiga Delitracker Emulator
• XMMS and XMMS2
• Extended Module Player (XMP)
• TiMidity

AmigaOS

• DeliTracker
• Digi Booster Pro

BeOS

• Thomas Neumann's APlayer for BeOS x86 & PPC BeBoxen

Multiplatform engines (for software development)

• IBXM - XM/MOD/S3M player in Java
• JavaMod - IT/XM/MOD/S3M player in Java
• uFMOD - native XM player for Win32, Linux, Unix/BSD and KolibriOS
• MiniFMOD - native XM player for Win32 and Linux

Module file converters

• PlayerPro for Mac OS X (PPC/Intel) and Mac OS Classic. Now freeware, it is no longer under development. It can still be found, but outside of the official site. It can play a rather wider scope of formats than CocoModX, as well as edit them or create new ones http://playerpro.sourceforge.net

Hardware module file players

• TRAXMOD Portable Digital Audio Player for dsPIC/ARM http://www.k9spud.com/traxmod/

External links

• Amiga Music Preservation - Tens of thousands of Amiga music modules to download
• Exotica - Lots of music modules, dedicated to "unusual" tracker formats from the Amiga
• Chiptune.com - Lots of chiptunes
• Mod Archive - Not the largest mod file site but seems to be the hub for new music
• Scene Music - "Nectarine" - An internet radio station playing modules
• Aminet's MOD Archive - Aminet archive's mod file section - the hub of the modscene for years
• Modland - FTP server with more than 300,000 modules in several formats, mostly MOD, XM, S3M and IT, sorted by author.
• United Trackers - Non-profit organization of musicians supporting the tracking scene (est. 1997).
• Kohina - Scandinavian internet radio site that hosts module tunes.
• Modulez.org - Modscene portal
• Boray Mod Music - Mods by Anders Persson
• The Unofficial XM File Format Specification: FastTracker II, ADPCM and Stripped Module Subformats - File format specification by Fredrik Huss (one of the creators of the original XM module format). Additions and corrections made by ByteRaver, Wodan and Quantum.