Knight Lore: Routine at B419

B419: Play Appearing Sound

Used by the routine at HandlePlayerAppearing.

Plays the rising sound of the sparkles that show the player appearing. The number of cycles depends on the sprite number of the sparkle.

Input
IX	Address of the sparkle object

Make a beep for each remaining frame.

PlayAppearingSound

B419

LD A,(IX+$00)

Fetch the graphic number of the sparkle.

B41C

RLCA

Rotate it left twice.

B41D

RLCA

B41E

AND %00011111

Keep the lowest five bits.

B420

OR %00000011

Make sure that there are at least three cycles.

B422

LD C,A

Set C to the number of cycles.

PlayAppearingSound_NextBeep

B423

LD A,C

Fetch the cycle counter.

B424

RLCA

Multiply it by four to get the pitch.

B425

RLCA

B426

LD B,A

Set B to the pitch.

B427

Play a single cycle of the tone.

B42A

DEC C

Decrease the cycle counter and loop back to PlayAppearingSound_NextBeep until it is zero.

B42B

B42D

RET

Return.

View the equivalent code in;