Changes

BIOS Sound Functions

116 bytes added, 06:25, 22 April 2021
/* Set Tone Envelope */ This byte has 8 bits
In: A=Envelope number (1..15), HL=Pointer to Data (must be >3FFFh)
The data block starts with a header byte:
bit7 envelope type (0=software, 1=hardware) bit6-0 number of following 3-byte parameters (1..5)
The following 3-byte parameters can be (when Byte 0, Bit7=0):
Byte 0 Number of steps (01h..7Fh)
In: A=Envelope number (1..15), HL=Pointer to Data (must be >3FFFh)
The data block starts with a header byte:
bit7 envelope type (0=software, 1=hardware) bit6 repeat flag (0=one shot, 1=repeat envelope) bit6bit5-0 number of following 3-byte parameters (1..5)
The following 3-byte parameters can be (when Byte 0 is <F0h):
Byte 0 Number of steps (01h..EFh)
BD34 MC_SOUND_REGISTER ;in: A=PSG index, C=PSG data
Directly writes to a PSG register (this would conflict with the other SOUND functions).
[[Category:BIOS]]
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