I'm trying to convert the envelope generator's attack/decay rates, the 6-bit values, into actual time. The only documentation of the YM2612 that I know of
(http://www.smspower.org/maxim/docs/ym2612/index.html) doesn't talk about this at all. Some manuals for related chips (OPL3, OPM) give tables, but they are different from one another and the different clocks probably mean that the tables don't apply.
Does anyone know exactly what the chip does with these rate values, and where the emulator writers know that from?
Also, if someone knows where I can get the YM2612 manual, I would appreciate it (although the exact wait mechanism isn't likely to be described since it isn't in other Yamaha FM chips' manuals).