Yamaha tuning info

Contrary to what was stated previously, you _can_ set the carrier
on the TX81Z to a Hz value. The precision depends on the register,
and is 1Hz at best. This may correspond to the internal frequency
representation, in which case the tuning should be accurate.
Choose the right fundamental and it should work for JI ... except
the way it's set up I don't think it's any use. Stick to tuning
tables, and put up with the imprecision.