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⌂ ∞ ▽ Elite on the 6502

Sound: BDRO5

[Commodore 64 version]

       Name: BDRO5                                                   [Show more]
       Type: Subroutine
   Category: Sound
    Summary: Process music command <#5 fh1 fl1 fh2 fl2 fh3 fl3> to set the
             frequencies and voice control registers for voices 1, 2 and 3
  Deep dive: Music in Commodore 64 Elite

    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * BDJMPTBH calls BDRO5
             * BDJMPTBL calls BDRO5




.BDRO5

 JSR BDlab3             ; Fetch the next two music data bytes and set the
                        ; frequency of voice 1 (high byte then low byte)

 JSR BDlab5             ; Fetch the next two music data bytes and set the
                        ; frequency of voice 2 (high byte then low byte) and the
                        ; vibrato variables for voice 2

 JSR BDlab7             ; Fetch the next two music data bytes and set the
                        ; frequency of voice 3 (high byte then low byte) and the
                        ; vibrato variables for voice 3

 JSR BDlab4             ; Set the voice control register for voice 1 to value1

 JSR BDlab6             ; Set the voice control register for voice 2 to value2

 JSR BDlab8             ; Set the voice control register for voice 3 to value3

 JMP BDskip1            ; Jump to BDskip1 to process the next nibble of music
                        ; data