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Here's a little from Mapping the Amiga:
Most sound-digitizing software specifies the waveform frequency by the number of samples per second, not by the period value that the Amiga's hardware expects. The equation for converting the samples-per-second to period value is:
Period = 3579564 / Samples-Per-Second
So, if you want to play a sound that was sampled at 12 kHz, use a period value of 3579546 / 12000 = 298
To calculate the period value for a note, use the equation
Period = 3579546 / (Length * Frequency)
where Length is the size of the waveform in bytes and Frequency is the note's frequency value obtained from the table:
A = 440
A# or Bb = 466
B = 494
C = 523
C# of Db = 554
D = 587
D# or Eb = 622
E = 659
F = 699
F# or Gb = 740
G = 784
G# or Ab = 831
To raise a note by an octive, divide the period value by 2.
It also states the lowest value you should ever use is 124, since this is about as fast as the Amiga can go. If you use a value less than 124, you run the risk of having the same 2 bytes of data output twice in a row.
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