Used by the routines at 30053 (to make the cash bonus/key sound effect) and 64618 (to make the sound effect for when Sam hits the ground after being dropped by a gangster).
Input
A
Border colour
C
Pitch
DE
Duration
Output
64740
XOR 16
Flip bit 4 of A (the speaker bit)
64742
OUT (254),A
Set the border colour and change the speaker state