Nintendo GAME BOY Programming Manual page 198

Game Boy Programming Manual
The lower parts and blocks are set in the same manner.
Code Summaries
a) Length Data (step time)
This is the length (step time) to the subsequent sound; it corresponds to the length of the sound
envelope. The code corresponding to each sound envelope is shown in the following table.
Please use the appropriate code in the settings.
Note Length
Sixteenth
note
Dotted
sixteenth note
Eighth note
Note: For triplets and thirty-second notes, convert using the above values.
b) Velocity (volume) + gate time
Velocity expresses the volume as a percentage. Here it can be set to 16 levels using the lower-
order 4 bits (d0 – d3).
Gate time expresses as a percentage the length that the sound is actually emitted. It can be set
to 8 levels using the higher-order 3 bits (d4 – d6).
Changing these values provides legato and staccato effects.
The following table lists the values defined by the SGB sound driver.
The settings are designated using the codes for the listed velocities (VELOCITY) and gate times
(GATE_TIME).
Code Note Length
6
Dotted eighth
note
9
Quarter note
12
Dotted quarter
note
198
Code Note Length
18
Half note
24
Dotted half note
36
Whole note
Code
48
72
96