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synthead / ym2420_arduino

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Slightly out-of-tune when directly following datasheet to calculate f_numbers. Suggested f_numbers also out-of-tune. #1

Open synthead opened 9 years ago

synthead commented 9 years ago

When using the YM2413 datasheet's suggested method to calculate f_numbers (page 15 on the page, PDF page 18), some keys are inconsistently out-of-tune (some sharp, some flat). The suggested values in the table also produce out-of-tune frequencies. In addition, using floor and ceil did not fix the issue.

This might be a difference between the YM2413 and the YM2420 used in this project. If this is the case, it'd be best to calculate real values via traditional tuning methods and try to make a new equation based off the data.

madscient commented 7 years ago

In that datasheet, fM and fsam are handled roughly, ie 3.6 MHz and 50 kHz. Accurately, it should be calculated with 3.579545MHz and 49.7159KHz.