Alesis QSR 64 Reference Manual page 86

Editing Programs: Chapter 6
Page 1 in the Amp Envelope Function lets you adjust the Decay time of the selected
drum (00 to 99, Gate00 to Gate99). If this is set to 0, only the very beginning of the
drum sample is played; setting this to 99 will cause the entire drum sample to play.
When set above 99, the Decay uses a gated mode. The Decay can still be set between 0
and 99, but in 5-step increments (e.g., Gate00 = Decay setting of 0 with gating, Gate05
= Decay setting of 5 with gating, etc.). Gating means that the drum sound will
continue to be played as long as the key is held. This is useful for longer sounds, like
cymbals, when you wish to hear a short crash by playing a short note but can still hear
a longer crash by keeping the note held down.
QSR Reference Manual 39