* a distinct rhythm section, which incorporates a noise generator with some of the parts above to provide a few fixed percussion noises.
<br>
==== Waveforms ====
The original OPL only has access to the sine wave.
From the OPL2 onwards other waves are also available, specifically a half sine (i.e. the positive part only, silence for the second half of the period), rectified sine (the positive part repeated twice per cycle) or quarter sine (just the first ramp from 0 to 1, repeated twice, providing harmonics a lot like a sawtooth).
The OPL3 goes even further, adding some extra sine options plus a square wave and a logarithmic sawtooth.
[[File:Waveforms OPL3.jpg]]
<br>