Synthpopalooza Posted May 22, 2014 Share Posted May 22, 2014 Got an interesting question ... I have been coding music on the 8-bit (and 7800) using a tabled note and duration system. When the tempo is 120 bpm, it's all straightforward. I've calculated these note durations (using jiffies, or 1/60 cycles in NTSC) Whole note: 120 Half note: 60 Dotted half: 90 Quarter note: 30 Dotted Quarter: 45 Eighth note: 15 Dotted eighth: 22 Sixteenth note: 7 or 8 (using 7 if it's the second of a pair of sixteenths) The tricky part comes, when I use different tempos. For instance, if I use a tempo of 115, I need a whole new set of values. Is there a formula for calculating the length of a whole note in jiffies, when you are given the song's tempo in bpm? Quote Link to comment Share on other sites More sharing options...
Chilly Willy Posted May 22, 2014 Share Posted May 22, 2014 There are 3600 jiffies per minute (NTSC, it's 3000 for PAL). Now just divide the beat into that to get the value for quarter notes. All the rest are just various fractions/multiples of that value. For example, 3600/120 = 30, which is what you got for the quarter note at 120 bpm. A half note is twice that, while an eighth not is half that. And so on. Quote Link to comment Share on other sites More sharing options...
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