Impulse Tracker

Impulse Tracker

Impulse Tracker
Developer(s) Jeffrey Lim
Stable release 2.14 / April 8, 1999
Written in Assembly language
Operating system MS-DOS
Type Tracker

Impulse Tracker is a multi-track digital sound tracker (music sequencer). It was one of the last tracker programs for the DOS platform. It was authored by Jeffrey "Pulse" Lim,[1] and example music was provided by Jeffrey Lim and Chris Jarvis. The first released version is from year 1995 and the last version, v2.14 Patch #5, was released April 8, 1999. On February 16, 2014, Jeffrey Lim announced that he would release the complete source code of Impulse Tracker as part of its 20 year anniversary.[2] On October 19, 2014, the source code was released on Bitbucket.


The software was distributed as freeware, though for a fee the author supplies extra features, such as support for WAV output and co-editing songs over IPX networks. After the stereo WAV writer plugin was publicly pirated,[3] the original author announced that he would discontinue development after version 2.14. Impulse Tracker was coded in Assembly language.[4]

Impulse Tracker's interface was influenced by that of Scream Tracker 3.[5]


Like in most module editors, music is arranged on a grid of channels. Each supports note on and note off instructions similar to MIDI. Impulse Tracker modules use the .IT file extension.

New Note Actions (NNAs) is a feature that handles commands received on the same channel as another instrument which is still playing. NNAs allow the user to customize the subsequent action:

  • Cut: The new instrument replaces the current instrument.
  • Continue: The old instrument continues to play using its ADSR curve.
  • Off: The old instrument begins the release section of its ADSR curve.
  • Fade: The old instrument fades out to 0 volume at a designated rate overriding the ADSR curve.

Impulse Tracker supports hardware MIDI channels on the Gravis Ultrasound, InterWave and Sound Blaster 32 card families (provided enough RAM is available).

Compatible software

Other music-playing software that supports the IT file format include Media Player Classic, Winamp (Win32), VLC, Cowon jetAudio, XMMS (X11 Linux/Unix), TiMidity, MikMod, ModPlug Tracker, Renoise (Win32, GNU/Linux and Mac OS X), XMPlay, and Schism Tracker (Win32, Linux, Wii and Mac OS X) which is an Impulse Tracker reimplementation.[6]

IT file format

The .IT file format is the format native to Impulse Tracker. It is similar to older formats such as .MOD, but features new additions such as new note actions which allow the user to customize subsequent actions on receiving commands from the same channel as the one playing.

Some player software supports the .ITZ format, which is a renamed zip file that contains a .IT file.


Erez Aizen of Infected Mushroom and Shiva Shidapu composed his first trance music on Impulse Tracker.[7] Ian Stocker used IT with other software in his collaboration for the music in the Nintendo DS version of The Sims 2.[8]

The video games Pocket Tanks and Grid Wars use the IT format for some of their songs. Various games by Epic Games such as the first Unreal and Unreal Tournament as well as Deus Ex used the IT format in an "UMX" container format.[9][10]

The video game composer and demoscener Andrew Sega used Impulse Tracker extensively in his demoscene days.

Trance producer Sean Tyas began his music production career using Impulse Tracker.[11] Electronic rock musician Blue Stahli has revealed to have used Impulse Tracker and other trackers in the past.[12]

Also Deadmau5 career began in the mid 1990s with a chiptune and demoscene movements-influenced sound with the Impulse Tracker.[13]

See also

Sound examples

  • Pale Dreams - included with an early release of Impulse Tracker (.IT module)
  • IndusTree's Homesick (ogg)
  • Gerador Zero - Zero (mp3) (.IT module)
  • Come To Dreamland by Fernando Pereira Aratti (MP3 version)(.IT module)
  • Shiva Shidapu - Power of Celtic (.IT module) - as heard on Shiva Shidapu's "Shiva Space Technology" album

External links

  • Impulse Tracker source code on Bitbucket
  • Impulse Tracker website
  • Jeffrey Lim's blog


  1. ^ Leonard, Andrew (April 29, 1999). "Mod love". Salon Media Group. Retrieved 2010-05-17. 
  2. ^ Lim, Jeffrey (February 16, 2014). "20 years of Impulse Tracker". Retrieved February 17, 2014. 
  3. ^ Lim, Jeffrey. "Impulse Tracker Changelog". Retrieved 2010-07-17. 
  4. ^ Lim, Jeffrey. "Impulse Tracker". Retrieved 2010-12-07. 
  5. ^ Lim, Jeffrey. "Features of Impulse Tracker". Retrieved 2009-04-07. 
  6. ^ Matsuoka, Claudio (2007-11-04). "Tracker History Graphing Project". Retrieved 2011-01-29. Tracker History Graph 
  7. ^ Sean Davidson (Jan 3, 2003). "Trance Mushrooms to infect Pune". The Times of India. Retrieved 2010-05-16. 
  8. ^ Andy Jones (January 10, 2006). "From a Distance: The Virtual Collaboration that Helped Score The Sims 2 DS/GBA". Gamasutra. Retrieved 2010-05-16. 
  9. ^ Information on how to extract IT files out of UMX containers
  10. ^ "Interview with Alex Brandon". Retrieved 2009-01-10. 
  11. ^ Sean Tyas interview
  12. ^ Blue Stahli twitter profile
  13. ^ Burns, Todd L. (2008-09-30). "Deadmau5: It's complicated". Retrieved 2014-09-03. I was in my Mom's basement tooling away on Impulse Tracker on a 386 just doing Nintendo music until some Loop Library company hired me as a producer.