Sound: HYPNOISE

       Name: HYPNOISE                                                [Show more]
       Type: Subroutine
   Category: Sound
    Summary: Make the sound of the hyperspace drive being engaged
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * LL164 calls HYPNOISE


.HYPNOISE

 LDY #sfxhyp1           ; Call the NOISE2 routine with Y = sfxhyp1, a frequency
 LDA #$F5               ; of 240 in X, and A set as follows:
 LDX #240               ;
 JSR NOISE2             ;   * Low nibble of A = release length of 5
                        ;
                        ;   * High nibble of A = sustain volume of 15

 LDY #sfxwhosh          ; Call the NOISE routine with Y = sfxwhosh to make the
 JSR NOISE              ; sound of the ship launching

 LDY #1                 ; Wait for 1/50 of a second (0.02 seconds) on PAL
 JSR DELAY              ; systems, or 1/60 of a second (0.017 seconds) on NTSC

 LDY #(sfxhyp1+128)     ; Call the NOISE routine with Y = sfxhyp1 + 128, which
 BNE NOISE              ; makes the sfxhyp1 hyperspace effect, but without first
                        ; checking to see if it is already playing (so the
                        ; effect can layer on top of the first sound effect we
                        ; made above)
                        ;
                        ; The call to NOISE returns from the subroutine using a
                        ; tail call (this BNE is effectively a JMP as Y is never
                        ; zero)