anacrucix

I'm designing a scale based arpeggiator (as opposed to a chromatic one), but for this to function correctly, i need to be able to figure out what a note is from it's midi number, i basically want to discard the information about what octave a note is in, and give notes the following values -

without any reference to the octave, e.g if someone presses A-1, i get an output of 0, if someone presses A-6, i get an output of 0. If someone pressed E-4 I would get an output of 7, can anyone think of a way of doing this?

I'm designing a scale based arpeggiator (as opposed to a chromatic one), but for this to function correctly, i need to be able to figure out what a note is from it's midi number, i basically want to discard the information about what octave a note is in, and give notes the following values - 

A 0
A# 1
B 2
C 3
C# 4
D 5
D# 6
E 7
F 8
F# 9
G 10
G# 11

stripping-out-the-note-from-the-midi-value

thanks so much man, you wouldn't believe the workarounds i've been trying! 

modulus can be used for a bunch of things, take a look at another example:

stripping out the note from the midi value?