Nightshade: Routine at C3BD

C3BD: Play Sound Effect

Used by the routine at StartGame.

Plays the next note of the current sound effect. The note counter is held at NoteCounter and the number of the sound effect at SoundNumber. A sound effect is started by setting the note counter to the number of notes.

The sound effects are:

Effect	Sound
00, a new cell
01, a speed bonus
02, a health bonus
03, an item

Count down the notes of the current sound effect.

PlaySoundEffect

C3BD

LD HL,$BBF9

Point at the counter of notes still to play.

C3C0

LD A,(HL)

Return if there are no more notes to play.

C3C1

AND A

C3C2

RET Z

C3C3

DEC (HL)

Count down a note.

C3C4

EX AF,AF'

Keep the note counter in AF'.

C3C5

INC HL

Point at the number of the sound effect.

Find the pitch of this note.

C3C6

LD A,(HL)

Fetch the number of the sound effect.

C3C7

LD BC,$C3D8

Point at the table of sound effects.

C3CA

CALL GetTableEntry

Fetch the address of the notes of the sound effect.

C3CD

EX AF,AF'

Get the number of the note back from AF'.

C3CE

LD C,A

Use it as the distance along the notes.

C3CF

LD B,$00

Make the distance a whole number of bytes.

C3D1

ADD HL,BC

Find the address of the note.

C3D2

LD B,(HL)

Fetch the pitch of the note.

C3D3

LD C,$0C

Set the length of the note.

C3D5

JP PlayTone

Jump to PlayTone to play the note.

View the equivalent code in;