Sound: BDlab3

       Name: BDlab3                                                  [Show more]
       Type: Subroutine
   Category: Sound
    Summary: Fetch the next two music data bytes and set the frequency of
             voice 1 (high byte then low byte)
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * BDRO1 calls BDlab3
             * BDRO4 calls BDlab3
             * BDRO5 calls BDlab3


.BDlab3

 JSR BDlab19            ; Increment the music data pointer in BDdataptr1(1 0)
                        ; and fetch the next music data byte into A

 STA SID+$1             ; Set SID register $1 to the music data byte we just
                        ; fetched, which sets the high byte of the frequency
                        ; for voice 1

 JSR BDlab19            ; Increment the music data pointer in BDdataptr1(1 0)
                        ; and fetch the next music data byte into A

 STA SID+$0             ; Set SID register $0 to the music data byte we just
                        ; fetched, which sets the low byte of the frequency
                        ; for voice 1

 RTS                    ; Return from the subroutine