Impulse Tracker

A multi-track digital sound sequencer proliferated on the DOS platform. It was authored by Jeffery Lim and discontinued after version 2.15. It reigned among the popular trackers of its time including ScreamTracker 3 (.s3m)and FastTracker (.xm).

Like most MOD editors music is arranged into a grid of channels, each channel containing key-on and optional key-off instructions not unlike MIDI.

One of the features which set this MOD editor apart was NNAs, New Note Actions. If a new key-on command is received in the same channel as another instrument which is still being played, NNAs allow the user to customize the action that next occurs:

• Cut: New instrument sound replaces current playing instrument.
• Continue: Old instrument continues to play following its defined ADSR[?] curve.
• Off: Old instrument instructed to begin release section of its ADSR curve.
• Fade: Old instrument fades out to 0 volume at a designated rate overriding any ADSR information.

See also tracker, MOD