Nightshade: Routine at C3F4

C3F4: The sound of a throw

Used by the routine at KNIGHT_THROWS.

32 single waves; each half-wave count is the step count less the one before, so the counts alternate between a short one and a long one: a high note and a low one, interleaved. KNIGHT_THROWS plays it as an antibody or an object leaves the knight's hand, B being 11 less the place on the panel it came from, counted from the bottom place as 0 (measured for the sounds page). Pentagram's bolt firing.

Input
B	the count to start from

FIRE_SOUND

C3F4

LD C,$20

for C = 32 down to 1: one wave at C less the last count

FIRE_SOUND_0

C3F6

LD A,C

C3F7

SUB B

C3F8

LD B,A

C3F9

CALL CLICK

C3FC

DEC C

C3FD

JR NZ,FIRE_SOUND_0

C3FF

RET