ta in a pattern division)
7654-3210 7654-3210 7654-3210 7654-3210
wwww xxxxxxxxxxxxxx yyyy zzzzzzzzzzzzzz

    wwwwyyyy (8 bits) is the sample for this channel/division
xxxxxxxxxxxx (12 bits) is the sample's period (or effect parameter)
zzzzzzzzzzzz (12 bits) is the effect for this channel/division

If there is to be no new sample to be played at this division on this
channel, then the old sample on this channel will continue, or at least
be "remembered" for any effects. If the sample is 0, then the previou