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MOD (file format)
MOD (file format)
MOD (file format)
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MOD
Filename extension
.mod
Internet media type
audio/mod, audio/x-mod
Magic number4 bytes "M.K." at offset 0x438
Developed byKarsten "Obi" Obarski
Initial release1987
Type of formatVideo/music
Extended toXM

MOD is a computer file format used primarily to represent music, and was the first module file format. It contains a set of instruments in the form of samples, a number of patterns indicating how and when the samples are to be played, and a list of what patterns to play in what order. MOD files use the “.MOD” file extension, except on the Amiga which doesn't rely on filename extensions and instead reads the file's header to determine its format.

History

[edit]

The first version of the format was created by Karsten Obarski for use in the Ultimate Soundtracker, a music tracker software released for the Amiga computer in 1987.[1][2] The format has since been supported by hundreds of playback programs and dozens of other trackers.[3]

The original version of the MOD format featured four channels of simultaneous audio playback, corresponding to the capabilities of the original Amiga chipset, and up to 15 instruments.

Later variations of the format have extended this to up to 32 channels and 31 instruments.

The format was designed to be directly playable on the Amiga without additional processing: for example, samples are stored in 8-bit PCM format ready to be played on the Amiga DACs, and pattern data is not packed. Playback required very little CPU time on an Amiga, and many games used MOD files for their background music.

A common misconception is that the magic number "M.K." in the 0x438 offset of MOD files are the initials of Mahoney and Kaktus, two prominent Amiga demomakers at the time, who played an important part in the popularity of the format. They in fact stand for the initials of Michael Kleps a.k.a. Unknown / DOC, another developer of the format.[4]

After the Amiga's production ceased, the MOD format has had continued popularity in the Demoscene and as background music for independent video games and Chiptunes. It is not uncommon to hear MOD music in keygens either.

Format overview

[edit]

A pattern is typically represented in a sequencer user interface as a table with one column per channel, thus having four columns – one for each Amiga hardware channel. Each column has 64 rows.

A cell in the table can cause one of several actions to happen on its column's channel when its row's time is reached:

  • Start an instrument playing a new note in this channel at a given volume, possibly with a special effect applied on it
  • Change the volume or special effect being applied to the current note
  • Change pattern flow; jump to a specific song or pattern position or loop inside a pattern
  • Do nothing; any existing note playing in this channel will continue to play

An instrument is a single sample along with an optional indication of which portion of the sample can be repeated to hold a sustained note.

Timing

[edit]

In the original MOD file the minimum time frame was 0.02 seconds, or a "vertical blanking" (VSync) interval, because the original software used the VSync timing of the monitor running at 50 Hz (for PAL) or 60 Hz (for NTSC) for timing.

The rate at which pattern data is played is defined by a speed setting. Each row in the pattern data lasts one vertical blanking (or 0.02 seconds) times the current speed setting. The speed setting varied from 1 to 255. In later versions of the format, the vertical blanking was replaced with an adjustable time period staying in the range [0.01, 0.078] seconds. The old speed setting command was replaced with a new one that was used to change both the old speed setting and the new adjustable time period. Unfortunately, some of the old functionality was broken, because the new speed setting command had an identical code value to the old command. Values in the range [1, 31] were interpreted as the old speed settings, but other values were regarded as modifications to the adjustable time period. Hence, values in the range [32, 255] used in some old songs broke in new versions of the player.

Further information on the MOD format can be found at the alt.binaries.sounds.mods FAQ.[5]

Other formats that use the MOD extension

[edit]

MOD is the file extension for several other applications:

  • The video file format used on many digital camcorders, such as the JVC Everio, the Canon FS100 and the Panasonic D-Snap SD-card camcorders.[6]
  • Game modules in Neverwinter Nights.
  • AMPL model files.
  • Old phpBB modification templates.
  • Module files in Femap
  • The extension for the binary variant of the Wavefront .obj format.
  • The extension for some games using the Vassal game engine.
  • The extension for Fortran module files.[7]
  • The extension for legacy Visual Basic module files, for versions before the release of Visual Basic .NET.
  • The extension for Go module files, used for package versioning.
  • Module for ABB Robotics IRC5 and S4 robot controllers. Contains robotic motion programs written in the language RAPID.
  • Lanner WITNESS simulation software model files
  • Paradox Development Studio uses a ".MOD" format for user-created modifications of their games.
  • DND adventure modules for Fantasy Grounds, a virtual tabletop application.
  • GNU GRUB boot modules (when found in /boot)
  • Modified ECU Map files when exported from ECM Titanium (ECU Map editing software)

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

MOD (file format)

View on Grokipedia
from Grokipedia
The MOD file format is a pioneering digital music container originating from the Commodore computer in the late 1980s, designed for tracker software to store and playback sequenced music using sampled waveforms and pattern-based instructions. It represents one of the earliest formats, embedding up to 31 audio samples (typically 8-bit PCM data) alongside sequencing data that specifies note events, durations, and effects across a fixed number of channels, usually 4 in its standard Amiga variant. This structure allowed for efficient, hardware-limited music production without requiring synthesizers, making it a staple in the and early computer game soundtracks. Developed initially with Ultimate Soundtracker by Karsten Obarski in 1987, the format evolved through tools like NoiseTracker and ProTracker, which expanded support from 15 to 31 instruments and introduced enhanced commands for effects such as volume adjustment, panning, and looping. The file begins with a 20-byte song title, followed by sample descriptions (including names, lengths up to 128 KB per sample, finetune values from -8 to +7 semitones, and default volumes), a song length indicator (1-128 patterns), a restart position, and an ordered list of patterns to play. Pattern data, stored in a grid of 64 rows per pattern, uses 4 bytes per row per channel to encode period (pitch), sample number, effect command, and parameter, all in Motorola byte order with signed sample data for Amiga compatibility. Variants like 8-channel "multichannel" MODs emerged on PCs, supporting more simultaneous voices but retaining the core 8-bit limitations. MOD files gained prominence in the 1980s and 1990s for their portability across platforms, including ports of trackers, and were widely used in games, music disks, and compositions due to low resource demands—requiring only sample playback and basic arithmetic for timing at rates like 50 Hz on PAL systems or 60 Hz on . Despite its simplicity, which constrained sample fidelity and polyphony compared to later formats like XM or IT, the MOD format's influence persists in modern trackers and emulators, with robust support in software such as for rendering and preservation. Files are identified by like "M.K." or "4CHN" at offset 0x438, and extensions are typically .mod, though not always enforced. Its legacy underscores the demoscene's role in democratizing music creation, fostering a community-driven toward more advanced tracker formats.

History and Development

Origins and Creation

The MOD file format originated in 1987 with the development of software by German programmer Karsten Obarski for the platform. Designed as a pioneering tool for music composition within the constraints of early hardware, introduced the concept of module files to enable efficient storage and playback of digital music. This format marked the birth of tracker-based music production, allowing users to sequence short audio samples into complex compositions without requiring extensive waveform data or real-time synthesis. The original specifications were tailored to the Amiga's Paula sound chip, limiting modules to four audio channels for simultaneous playback and supporting up to 15 instruments, each consisting of 8-bit pulse-code modulation (PCM) samples directly compatible with the system's digital-to-analog converters (DACs). These constraints ensured low CPU overhead, making it feasible to integrate music into resource-intensive applications like games and demos. Sample lengths were capped to fit within available memory, typically ranging from a few kilobytes per instrument, promoting creative reuse of sounds rather than full recordings. The primary purpose of the MOD format was to empower artists, game developers, and hobbyist musicians to craft intricate, multi-layered tracks using a grid-based editor, where notes, volumes, and effects could be arranged modularly. By separating from sequencing instructions, it facilitated compact file sizes—often under 100 KB—ideal for distribution in the late 1980s era. This approach revolutionized music production, shifting from hardcoded chiptunes to sample-driven compositions that mimicked professional studio techniques on consumer hardware. A key identifier in the format is the magic number "M.K.", located at byte offset 0x438 (decimal 1080), which serves to distinguish standard 31-instrument MOD files from earlier 15-instrument variants lacking this marker; its inclusion helped early players and loaders verify file integrity and sample count during parsing. While the original modules did not include this signature, it became integral to 's evolution, ensuring compatibility across subsequent tools.

Evolution Across Trackers

Following the introduction of the MOD format by in 1987, which established the original 4-channel limitation, subsequent trackers began refining the format starting in 1989. NoiseTracker, released in August 1989 by Pex Tufvesson (Mahoney) and Anders Berkeman (Kaktus) of North Star, marked the first major evolution by addressing bugs in the original software and expanding the instrument limit from 15 to 31 samples. It also enhanced pattern editing capabilities, allowing for more intuitive composition through improved user interface elements like better cursor navigation and undo functions, while preserving with existing 15-instrument files by lacking a dedicated format signature. ProTracker, released in 1990 by the Amiga Freelancers group (original developers Lars Hamre, Anders Hamre, Sven Vahsen, and Rune Johnsrud), further advanced the format by standardizing the 31-instrument capacity and introducing finer volume control ranging from 0 to 64, enabling more nuanced sample mixing. It expanded the effects repertoire, including commands for tempo adjustment () and pattern delays, which allowed composers greater expressive flexibility beyond the hardware-tied constraints of earlier versions. This led to ProTracker's widespread adoption as the preferred tool in the community, with its "M.K." file signature helping players identify 31-instrument modules. Within the demoscene, these developments prompted informal standardization efforts, as groups favored ProTracker's features for their reliability and compatibility with demo productions. However, compatibility challenges persisted between 15-instrument (often signature-less) and 31-instrument files, requiring players to scan for the signature or default to the older format to avoid misinterpreting sample data lengths and causing playback errors. These refinements solidified the MOD format's role in the late 1980s Amiga era, profoundly influencing music in productions such as Fairlight's early intros, where sampled instruments combined with Paula chip synthesis created dense, replayable soundtracks.

Core Format Specifications

Header and Metadata

The header of a MOD file serves as the initial fixed-size structure containing essential metadata for the song title, sample descriptions, and playback sequencing, preceding the actual sample data and pattern information. This header varies in size between variants: 600 bytes for the 15-instrument format (common in early trackers like ) and 1084 bytes for the 31-instrument format (standard in and later tools). The structure ensures compatibility across Amiga-based music trackers by providing pointers and parameters for up to 31 discrete samples, which are raw 8-bit audio waveforms. The header opens with a 20-byte field for the song title, encoded in ASCII and padded with null bytes (0x00) to fill the space; titles are typically uppercase in original files and can include module author credits or descriptions. Immediately following are the sample descriptions, with 15 entries in the shorter variant or 31 in the longer one, each occupying exactly 30 bytes. Each description begins with a 22-byte ASCII sample name (padded with nulls), followed by a 2-byte big-endian value for the sample length in words (where 1 word equals 2 bytes, allowing up to 65535 words or 131070 bytes theoretically, though hardware limits practical sizes to around 32 KB per sample). The next byte encodes finetune as a 4-bit value in the low (0x00 to 0x0F, mapping to pitch shifts of 0, +1/8, +2/8, +3/8, +4/8, +5/8, +6/8, +7/8, -8/8, -7/8, -6/8, -5/8, -4/8, -3/8, -2/8, -1/8 semitones), while the subsequent byte specifies default as an unsigned value from 0 to 64 (where 64 represents full ). The description concludes with two 2-byte big-endian fields: repeat start position (offset in words from the sample beginning) and repeat length (duration in words, with a value of 1 indicating no loop). These fields enable basic looping and envelope control without embedded waveform data. After the sample descriptions, the header includes a 1-byte song length field (values 1 to 128), indicating the number of positions in the playback order before looping. This is followed by a 1-byte restart position, historically set to 0x7F (127) in modules to disable restarting or 0x78 in earlier formats, though it is largely obsolete and ignored by modern players in favor of pattern jump effects. The core sequencing data appears next as a 128-byte order list (also called the or position list), where each byte holds an 8-bit unsigned index (0 to 127) referencing a to play in sequence; values of 0x7F or higher typically signal the end of the . In 31-instrument files, the header terminates with a 4-byte ASCII signature (e.g., "M.K." for or "M!K!" for variants with extended pattern numbers), which identifies the format and ensures loader compatibility; 15-instrument files omit this field. MOD files employ the .mod file extension and are assigned the Internet media type audio/mod for web transmission and identification. This metadata setup allows efficient parsing by trackers and players, with the order list directly informing the sequence of patterns that follow the header and sample blocks in the file.

Sample and Instrument Storage

In the MOD file format, audio samples, which serve as the instruments, are stored as raw 8-bit signed (PCM) data in big-endian byte order, immediately following the pattern data section. Each sample's data block is a contiguous sequence of bytes representing the , with lengths specified in the earlier sample descriptors (not covered here). The total sample data for all instruments is limited to even byte counts, typically up to 128 KB per sample, though practical constraints from hardware often kept individual samples between 10 KB and 60 KB. Samples are stored sequentially without any interleaving or additional metadata between them, enabling direct memory loading for playback. The looping mechanism in MOD files supports three basic modes determined by the loop start and length values from the sample descriptors: non-looped playback (where the sample plays once to completion), forward looping (repeating a defined segment from the loop start to the loop end indefinitely), or no loop if the length is 1. Loop points are defined in words (16-bit units), ranging from 0 to 0xFFFF, which translate to byte offsets by multiplying by 2, ensuring even alignment. Forward loops begin at the specified start point and repeat the designated length segment, with the first two bytes of each sample often zeroed by players like to facilitate clean repetition or termination. The format does not natively support ping-pong looping (bidirectional playback), though some modern players may emulate it for compatibility; standard MOD playback relies solely on forward repetition for seamless sustains in instruments like pads or basslines. Instrument limits vary by MOD variant: the original Soundtracker format supports up to 15 samples (indexed 1-15), while extended versions like accommodate 31 samples (indexed 1-31). These samples function as monophonic instruments without multi-sample layering, modulation envelopes, or velocity sensitivity, reflecting the format's simplicity for Amiga's four-channel audio hardware. During playback, patterns reference these samples by index to trigger them on channels. MOD files store samples without any compression, preserving raw PCM data for immediate access by the Amiga's Paula sound chip, which required unpacked waveforms for real-time mixing. This uncompressed approach ensured low-latency playback but limited file sizes and sample quality to the era's hardware constraints, such as 8-bit resolution and no .

Pattern Encoding and Orders

In the MOD file format, musical represent the sequential arrangement of notes, samples, and effects across multiple channels, forming the core of the composition's structure. Each is allocated 1024 bytes, comprising 64 rows and 4 channels, with 16 bytes per row (4 bytes per channel). These are stored sequentially in the file immediately following the header, allowing for a maximum of 128 , though most modules utilize far fewer—typically 32 or less—to conserve space. Empty , which contain no note or effect data, are sometimes employed to facilitate pattern jumps or breaks during playback, enabling composers to skip sections without redundant storage. The encoding of data within each channel of a uses a compact 4-byte per row position, optimized for the Amiga's hardware constraints. The first byte combines the high of the period value (representing note , bits 11-8) with the high of the sample number (sample >> 4). The second byte holds the low 8 bits of the period value (bits 7-0). The third byte merges the high of the effect command with the low of the sample number (sample & 0x0F). Finally, the fourth byte provides the 8-bit for the effect. This packed format allows for efficient during playback, where a period value of zero indicates no new note, and a sample number of zero signifies no change from the previous sample assignment. The order list, also known as the pattern table, sequences the patterns to define the overall and is located at file offset 952, spanning 128 bytes. Each byte in this list references a pattern number from 0 to 127, dictating the order in which patterns are played during module playback; the effective song length is specified by a preceding byte (1-128), but the full list allows for loops or extensions. The total number of patterns in a module is determined by the highest index value in the order list plus one, ensuring only necessary patterns are loaded. In standard 4-channel modules identified by the "M.K." tag, indices are typically limited to 0-63, though later variants support higher values.
ByteBits BreakdownDescription
07-4: Period (11-8)
3-0: Sample high (sample >> 4)		High period and high sample nibbles
17-0: Period (7-0)Low period byte
27-4: Effect command
3-0: Sample low (sample & 0x0F)		Effect type and low sample nibble
37-0: Effect parameterEffect data value
This table illustrates the bit-level packing for a single channel entry, emphasizing the format's density for real-time processing on 1980s hardware.

Playback and Technical Details

Timing and Synchronization

The timing and synchronization in MOD files are fundamentally tied to the Amiga hardware's interrupt system, particularly the Complex Interface Adapter (CIA) chips, which provide precise control over playback interrupts independent of the video display. In the original implementation with , playback relied on vertical sync (VSync) interrupts at 50 Hz for PAL systems (approximately 0.02 seconds per tick) or 60 Hz for systems, with a fixed speed of 6 ticks per row, resulting in row advancement synchronized to the display . This VSync-based approach ensured basic synchronization but limited flexibility, as the tick duration was hardware-dependent and could vary slightly between PAL and Amigas due to differing clock rates of 7.093789 MHz and 7.159091 MHz, respectively. With the evolution to , timing shifted to using CIA interval timers (Timer A or B on CIAA or CIAB) for generating customizable interrupts, allowing the speed value (1 to 255 ticks per row) to control the number of interrupts before advancing a pattern row. The CIA timers operate at a base clock derived from the system clock divided by 10 (approximately 709 kHz for PAL), enabling precise tick durations adjustable via the timer preload value loaded into the CIA's 16-bit registers. This setup supports row periods ranging from about 0.01 seconds (at high speeds) to 0.078 seconds or more (at low speeds), providing greater rhythmic control without tying playback strictly to VSync. For tempo adjustments beyond simple speed changes, later implementations like use the CIA timer to approximate beats per minute (BPM), with the formula TimerValue = 1773447 / BPM for PAL systems yielding a default of 125 BPM at speed 6 (24 ticks per beat assuming 4 rows per beat). On systems, the equivalent yields around 150 BPM under the same conditions due to the faster clock. Compatibility challenges arise when playing ProTracker modules in earlier software like Ultimate Soundtracker, as the latter lacks support for CIA-based tempo control and finetuning, causing modules with adjusted periods or speeds to playback at incorrect pitches or timings tied to VSync rather than the intended precise interrupts. ProTracker's refined period tables and CIA-driven synchronization, which allow for sub-semitone accuracy and independent , often result in desynchronized or sped-up playback in VSync-locked environments, breaking exact speed reproduction. This hardware-specific design ensured reliable synchronization on original systems but required emulators and modern players to emulate both PAL/ clocks and CIA behavior for faithful reproduction.

Note Periods and Effects

In the MOD file format, notes are encoded as period values within pattern data, serving as frequency dividers for the Amiga's Paula audio chip to determine playback pitch. These periods follow a table structured with 12 semitones per octave, spanning approximately seven octaves from C-0 to B-6, though practical limits constrain usable values to avoid hardware distortion. The table assigns decreasing integer values to higher pitches, reflecting the inverse relationship between period and frequency; for instance, C-0 corresponds to a period of 1712, while B-3 maps to 113, ensuring compatibility with the Paula chip's 12-bit period register. This mapping approximates musical tuning, with each semitone step reducing the period to achieve roughly equal-tempered intervals, though slight deviations occur due to integer rounding for Amiga hardware constraints. The relationship between period and actual playback is defined by the f=3546895periodf = \frac{3546895}{\text{period}}, where 3546895 Hz represents the PAL Amiga's effective audio clock for the Paula chip's operation ( variants use 3579545 Hz instead). This yields sample playback rates from approximately 2 kHz for low notes to over 30 kHz for high ones, though the chip's DMA rate caps effective output around 28 kHz to prevent . Periods are stored as 12-bit values in bytes, allowing fine control over pitch while tying directly to sample triggering on note onset. Effects in MOD patterns modify these periods and other playback parameters via commands encoded in hexadecimal from 0x00 to 0x3F, with an additional parameter byte specifying intensity or target values. Common effects include (0xy, rapidly cycling through semitones x and y for chord simulation), up (0x1x, sliding pitch upward by x units per ), and down (0x2x, sliding downward). Other notable commands are tone (0x3x, gliding to a target note over x steps), volume slide (0xAx, adjusting sample volume up by x or down by y), panning (0x8x, setting position from left to right), and pattern jumps or breaks (0xBx or 0xDx, altering flow). Extended effects under 0xEx handle finer adjustments like fine or note cuts, enabling dynamic modulation without altering base periods. MOD files allocate a fixed four channels for simultaneous playback, corresponding to the Paula chip's hardware limits, with no additional beyond these channels. Early formats pan channels alternately (e.g., channels 1 and 4 left, 2 and 3 right), while later variants like those from NoiseTracker support explicit left/right stereo panning via effects for more flexible mixing. This channel structure ensures efficient use of hardware resources, with effects applying per channel to manipulate individual periods and volumes during pattern playback.

Variations and Extensions

ProTracker and 31-Instrument Variants

The variant of the MOD file format expanded the original specification to support up to 31 instruments, enabling more complex compositions on the platform. This extension primarily modified the file header to accommodate additional sample definitions, increasing the header size from approximately 600 bytes in the 15-instrument format to 1,084 bytes. Each of the 31 sample slots includes a 22-byte name field, followed by a 2-byte length (in words, big-endian), a 1-byte finetune value, a 1-byte default volume, a 2-byte loop start offset, and a 2-byte loop length, all in byte order. Files in this variant are identified by a 4-byte magic identifier at the end of the header, typically "M.K." for standard 4-channel modules with up to 64 patterns, or "M!K!" for those exceeding 64 patterns. Other identifiers like "4CHN", "6CHN", or "8CHN" denote channel configurations while still supporting 31 instruments. This header expansion adds roughly 480 bytes compared to the original 15-instrument format, which lacked the magic identifier and used only the first 15 sample slots. ProTracker introduced per-sample default volumes ranging from 0 to 64, providing finer control over playback amplitude on a where 64 represents full volume. Finetune values, stored as a signed 4-bit (-8 to +7 semitones in 1/8-semitone steps), allow precise pitch adjustments using one of 16 period tables for more accurate intonation. Extended effects enhance expressiveness, including note delay (EDx, delaying onset by x ticks), sample delay (EEx for row-level delays), and retrigger (E9x, restarting the sample every x ticks), which were not present in earlier formats. For compatibility, 15-instrument MOD files load seamlessly into by populating only the first 15 sample slots and ignoring the rest, with the absence of a valid magic identifier signaling the older structure. This ensured that legacy modules from trackers like SoundTracker could be edited without modification. The larger header slightly increases overall file sizes, but pattern and sample data limits remain unchanged, keeping modules efficient for hardware constraints.

Non-Music Uses of .MOD Extension

The .MOD file extension, originally associated with music module formats, is also employed by several non-music applications to distinguish these from audio-related uses. In , .MOD files represent a video recording format developed by and for tapeless digital camcorders, such as the Panasonic SDR series and JVC GZ-MG models, encoding standard-definition video streams typically at 720×576 resolution in 50i interlaced mode for PAL regions, along with AC-3 or Layer II audio, and gained prominence in early 2000s devices for DVD-quality capture. In programming languages like , .MOD files are compiler-generated module interface files that encapsulate definitions, procedures, and data types from MODULE constructs in , enabling modular code organization and reuse across programs without embedding implementation details. For video game modifications, .MOD files appear in specific contexts: in titles like , they function as descriptor files that specify mod metadata, supported languages, and directory mappings to override game assets for custom content creation. In BioWare's , .MOD files package resources such as textures, meshes, and narrative elements for deployment via ModMaker, facilitating community-driven enhancements to game assets.

Software Support and Legacy

Original Amiga Software

, developed by Karsten Obarski and released in late 1987 by German publisher EAS, marked the debut of tracker software on the platform and introduced the foundational MOD file format for storing modules. This pioneering editor enabled basic pattern-based composition through a grid interface where users entered notes, effects, and sample triggers across 4 audio channels, supporting up to 15 instruments in the form of 8-bit PCM samples. Its simple workflow, including a editor for sequencing patterns into songs, democratized production on the , allowing artists and game developers to create chiptune-style tracks without specialized hardware beyond the system's Paula . In 1989, NoiseTracker emerged as a enhancement to , authored by Per "Mahoney" Tuffvesson and Anders "Kaktus" Berkeman of the Northstar and Silents groups. Retaining the core MOD format constraints of 15 instruments and 4 channels, it introduced an improved with better , expanded effect commands like and for more dynamic sound manipulation, and enhanced sample editing tools. These refinements made composition more efficient for users, fostering wider adoption in the burgeoning while maintaining compatibility with earlier modules. ProTracker, first released in 1990 by the Amiga Freelancers group (including Lars and Anders Hamre), quickly became the dominant tracker on the , supplanting its predecessors due to its robust feature set and distribution model. It expanded MOD support to 31 instruments—each defined by sample data, length, finetune, and volume—while incorporating an integrated replayer routine that allowed non-raster-dependent playback for smoother performance in demos and applications. Additional enhancements, such as a dedicated sample editor, pattern loop commands, and up to 128 patterns per module, solidified its role as the standard tool for professional-grade music production throughout the . Among dedicated players, DeliTracker (initially released as SndPlay in 1992 by Hot Lips) stood out as a versatile utility for replaying MOD files and over 150 other formats, featuring CLI and GUI modes with playlist support and accurate emulation of original hardware timing. For in-game and demo integration, Future Composer—created by Jochen Hippel in 1987 and later iterated by groups like Superions—provided synthetic music routines optimized for real-time playback, powering soundtracks in titles like Rings of and various productions with procedural generation and volume/ effects.

Modern Playback and Editing Tools

is a free, open-source tracker program primarily for Windows and that supports importing and exporting MOD files across all major variants, including and 31-instrument formats. It offers comprehensive editing capabilities, such as pattern editing, sample manipulation, and effect processing, while maintaining compatibility with legacy behaviors for authentic playback. Active development continues into 2025, with the latest stable release, version 1.32.05.00, issued on November 9, 2025, incorporating enhancements to module format support. Loosening of VBlank timing heuristics in libopenmpt, which improved playback accuracy for modules like Guitar Slinger from Dizzy Tunes II, was introduced in version 0.6.0 in December 2021. Further adjustments to VBlank heuristics for MOD files were made in the 1.31 series in 2024, such as assuming CIA timing for long samples. MilkyTracker provides cross-platform editing for MOD files as an open-source application inspired by FastTracker II, available on Windows, macOS, , and other systems. It handles 31-instrument MOD variants through its instrument editor, which supports sample loading, envelope adjustments, and pattern sequencing tailored to MOD constraints. The tool emphasizes low-latency audio output and emulates /1200 resampling for period-accurate playback during editing. For playback, XMPlay serves as a lightweight Windows audio player with built-in support for MOD files, offering configurable playback modes such as 1.x or FastTracker II emulation to handle variations in timing and effects. Similarly, , a customizable audio player for Windows, supports MOD playback via the Module Decoder plugin, which leverages libopenmpt for decoding and rendering module formats including MOD. The libxmp library enables MOD support in embedded applications, powering playback in tools like through its module demuxer and decoder integration. On mobile and web platforms, ModArchive.org features a JavaScript-based browser player utilizing libxmp to and reproduce MOD files directly in web browsers, supporting a vast archive of modules with warnings for high CPU usage on complex tracks. For Android, apps like PlayerPro Music Player include MOD format support alongside plugins for extended tracker compatibility, allowing offline playback and basic editing on mobile devices.

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  30. https://lib.openmpt.org/doc/changelog.html
  31. https://lib.openmpt.org/libopenmpt/2021/12/23/release-0.6.0/
  32. https://milkytracker.org/about/
  33. https://milkytracker.org/docs/manual/MilkyTracker.html
  34. https://support.xmplay.com/article.php?id=28
  35. https://www.foobar2000.org/components/view/foo_openmpt54
  36. https://github.com/libxmp/libxmp
  37. https://trac.videolan.org/vlc/ticket/13055
  38. https://modarchive.org/
  39. https://play.google.com/store/apps/details?id=com.tbig.playerprotrial
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