Signetics 2650 & 2636 programming/PVI audio frequency chart

Frequency table
The chart below shows the audio frequency generated by the PVI when the value n is programmed into $1FC7.

Coded index table
This table is just one way of implementing an index table to look up integer values corresponding to a musical note to feed to the PVI sound register $1FC7. Each unit step in index value shift by one semitone. Stepping by 12 in the index value shifts by an octave.

The lookup table uses 85 bytes and covers the range B0 to B7 but could be shrunk by reducing the range, or by eliminating notes not used in the composition. Note that beyond D5 many notes are not available. PitchLUT: db 252  ; 0   B            db 238   ; 1   C            db 224   ; 2   C♯ / D♭            db 212   ; 3   D            db 200   ; 4   D♯ / E♭            db 189   ; 5   E            db 178   ; 6   F            db 168   ; 7   F♯ / G♭            db 158   ; 8   G            db 149   ; 9   G♯ / A♭            db 141   ; 10  A            db 133   ; 11  A♯ / B♭            db 126   ; 12  B            db 118   ; 13  C            db 112   ; 14  C♯ / D♭            db 105   ; 15  D            db 100   ; 16  D♯ / E♭            db 94    ; 17  E            db 88    ; 18  F            db 83    ; 19  F♯ / G♭            db 79    ; 20  G            db 74    ; 21  G♯ / A♭            db 70    ; 22  A            db 66    ; 23  A♯ / B♭            db 63    ; 24  B            db 59    ; 25  C            db 55    ; 26  C♯ / D♭            db 52    ; 27  D            db 49    ; 28  D♯ / E♭            db 46    ; 29  E            db 44    ; 30  F            db 41    ; 31  F♯ / G♭            db 39    ; 32  G            db 37    ; 33  G♯ / A♭            db 35    ; 34  A            db 33    ; 35  A♯ / B♭            db 31    ; 36  B             db 29    ; 37  C          Middle C            db 27    ; 38  C♯ / D♭            db 26    ; 39  D            db 24    ; 40  D♯ / E♭            db 23    ; 41  E            db 21    ; 42  F            db 20    ; 43  F♯ / G♭            db 19    ; 44  G            db 18    ; 45  G♯ / A♭            db 17    ; 46  A            db 16    ; 47  A♯ / B♭            db 15    ; 48  B            db 14    ; 49  C            db 13    ; 50  C♯ / D♭            db 12    ; 51  D            ;............................End of contiguous semitone intervals (chromatic scales) ;.......................The following notes may be useful to complete other scales: db 0    ; 52 db 11   ; 53  E            db 10    ; 54  F            db 0     ; 55 db 9    ; 56  G            db 0     ; 57 db 8    ; 58  A            db 0     ; 59 db 7    ; 60  B            db 0     ; 61 db 6    ; 62  C♯ / D♭            db 0     ; 63 db 0    ; 64 db 5    ; 65  E            db 0     ; 66 db 0    ; 67 db 4    ; 68  G            db 0     ; 69 db 0    ; 70 db 0    ; 71 db 3    ; 72  B            db 0     ; 73 db 0    ; 74 db 0    ; 75 db 0    ; 76 db 2    ; 77  E            db 0     ; 78 db 0    ; 79 db 0    ; 80 db 0    ; 81 db 0    ; 82 db 0    ; 83 db 1    ; 84  B
 * Octave 0
 * Octave 1
 * Octave 2
 * Octave 3
 * Octave 4
 * Octave 5
 * Octave 6
 * Octave 7