The basic time unit in traditional trackers is a
tick which comes from the original implementation on Amiga computers where trackers began. The
Spd value
is actually the
number of ticks per row, or a line of text you see in the pattern editor.
The
BPM value has a misleading name since it
controls the duration of ticks, not actual beats per minute. Setting Spd to 3, 6 or 12 makes BPM appear almost like actual BPM value, but it's not entirely accurate. Only a handful of Spd/BPM combinations result in song speeds that are synchronizable with modern sequencers. It's a little unfortunate but you can't rewrite history. :/
Some pointers on Spd values:
Using Spd 1 is not advised because it renders most pattern commands nonfunctional. This is because notes are triggered on the first tick and commands mostly come into effect on the following ones. If you only have one tick per row, they'll never get their chance.
If you're into making chiptunes and you like the sound of the 0xy arpeggio command..
it is wise to use a song speed value divisible by 3 in order that the arpeggio sequence can loop smoothly.
That's because a tracker arpeggio is made of 3 notes, the base note and 2 offsets. If you choose a Spd where those 3 notes aren't spread evenly among the ticks of your rows, some notes will get more attention from the replay. But that's a subjective thing, really. It may well be a desired effect sometimes.
