Version OS 1.0
13 Appendix
13.1 MIDI Implementation
13.1.1 Midi Note Commands
Each instrument has its own channel to send or receive midi notes. The note number is
added to the pitch of the instrument. The basic internal tuning is on note C1 (36) and is
added from there on to the internal pitch.
Instrument
Note Number
Note
Channel
Kick Drum
36-97
C1-C6
1
Snare Drum
36-97
C1-C6
2
Closed Hi Hat
36-97
C1-C6
3
Open Hi Hat
36-97
C1-C6
4
Clap
36-97
C1-C6
5
Rim Shot
36-97
C1-C6
6
Crash
36-97
C1-C6
7
Ride
36-97
C1-C6
8
X1 Sample
36-97
C1-C6
9
X2 Sample
36-97
C1-C6
10
FM Synth (max. 6 voices polyph.)
36-97
C1-C6
11
On channel 16, the Alpha Base offers a key mapping for all instruments. Each
instrument maps 4 notes on the keyboard. The pitch is added according to the 4 notes.
Instrument
Note Number
Note
Delta Pitch
(semitones)
Channel
Kick Drum
36-39
C1-D#1
0, 6, 12, 18
16
Snare Drum
40-43
E1-G1
0, 6, 12, 18
16
Closed Hi Hat
44-47
G#1-B1
0, 6, 12, 18
16
Open Hi Hat
48-51
C2-D#2
0, 6, 12, 18
16
Clap
52-55
E2-G2
0, 6, 12, 18
16
Rim Shot
56-59
G#2-B2
0, 6, 12, 18
16
Crash
60-63
C3-D#3
0, 6, 12, 18
16
Ride
64-67
E3-G3
0, 6, 12, 18
16
X1 Sample
68-71
G#3-B3
0, 6, 12, 18
16
X2 Sample
72-75
C4-D#4
0, 6, 12, 18
16
FM Synth (fix chord)
76-79
E4-G4
0, 6, 12, 18
16
110
ALPHA BASE Operating Manual