Rex: Routine at D37F

D37F: Configure sound channel and mixer register

Used by the routines at 9683, 9807, 99E3, 9BA7, 9D2D, 9E15, 9E3D, A0F8, B54C, B5A8, B810, CFB5, D204 and D22C.

Input
DE	Sound data address

D37F

PUSH IY

Save IY, IX and BC

D381

PUSH IX

D383

PUSH BC

D384

PUSH DE

Copy DE into IY

D385

POP IY

D387

CALL $D390

Configure sound channel and mixer register

D38A

POP BC

Restore IY, IX and BC

D38B

POP IX

D38D

POP IY

D38F

RET

Configure sound channel and mixer register

D390

LD A,(IY+$00)

Set IX to the base address for the channel to configure

D393

DEC A

D394

SLA A

D396

SLA A

D398

SLA A

D39A

LD C,A

D39B

LD B,$00

D39D

LD IX,$D5CA

D3A1

ADD IX,BC

D3A3

LD A,(IY+$02)

Set number of tones

D3A6

LD (IX+$00),A

D3A9

LD A,(IY+$06)

Set variation counter

D3AC

LD (IX+$01),A

D3AF

PUSH IY

Set address for sound data

D3B1

POP HL

D3B2

LD BC,$0006

D3B5

ADD HL,BC

D3B6

LD (IX+$02),L

D3B9

LD (IX+$03),H

D3BC

LD A,(IY+$04)

Set base fine and coarse pitch

D3BF

LD (IX+$04),A

D3C2

LD A,(IY+$05)

D3C5

LD (IX+$05),A

D3C8

LD A,(IY+$03)

Set channel volume

D3CB

LD (IX+$07),A

D3CE

LD A,(IY+$01)

Set A to the data mixer

D3D1

CP $00

Jump forward if not zero

D3D3

JP NZ,$D3E9

D3D6

LD B,(IY+$00)

Disable noise for selected channel

D3D9

LD C,$04

D3DB

SLA C

D3DD

DJNZ $D3DB

D3DF

LD A,($D5ED)

Disable noise for the selected channel into the current data mixer

D3E2

OR C

D3E3

LD ($D5ED),A

D3E6

JP $D41A

Send this data to the mixer register

D3E9

LD A,($D5ED)

Set B the current data mixer

D3EC

LD B,A

D3ED

LD A,(IY+$00)

if channel 1 then disable tone in channel 1 and enable noise in channel 1

D3F0

CP $01

D3F2

JP NZ,$D3FC

D3F5

RES 3,B

D3F7

SET 0,B

D3F9

JP $D40C

Jump to update data mixer

D3FC

CP $02

if channel 2 then disable tone in channel 2 and enable noise in channel 2

D3FE

JP NZ,$D408

D401

RES 4,B

D403

SET 1,B

D405

JP $D40C

Jump to update data mixer

D408

RES 5,B

if channel 3 then disable tone in channel 3 and enable noise in channel 3

D40A

SET 2,B

D40C

LD A,B

Update data mixer

D40D

LD ($D5ED),A

D410

CALL $D41A

Send this data to the mixer register

D413

LD A,(IY+$01)

Copy noise/tone enable/disable

D416

LD (IX+$06),A

D419

RET

This entry point is used by the routine at D346.

D41A

LD A,($D5ED)

D41D

LD D,$07

D41F

LD E,A

D420

CALL $D4F1

D423

RET