Changes
/* Set Volume Envelope */ Precise bit7 content
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):