From: karri <karri@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Tue, 11 Dec 2012 12:33:50 +0000 (+0000)
Subject: Add basic sound support
X-Git-Tag: V2.14~127
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=7e5149d7f55f6773179f2c06aa9511bedab6c9f4;p=cc65

Add basic sound support

git-svn-id: svn://svn.cc65.org/cc65/trunk@5947 b7a2c559-68d2-44c3-8de9-860c34a00d81
---

diff --git a/libsrc/lynx/lynx-snd.s b/libsrc/lynx/lynx-snd.s
new file mode 100644
index 000000000..1a276f543
--- /dev/null
+++ b/libsrc/lynx/lynx-snd.s
@@ -0,0 +1,124 @@
+;
+; Sound driver for the Atari Lynx.
+;
+; Karri Kaksonen and Bjoern Spruck, 11.12.2012
+;
+
+	.include	"lynx.inc"
+	.include	"zeropage.inc"
+
+	.export		_lynx_snd_init
+
+;----------------------------------------------------------------------------
+; ZP variables that go into APPZP
+;
+
+	.segment "APPZP" : zeropage
+
+SndSema:		.res	1
+SndPtrTmp:		.res	2
+SndTmp:			.res	2
+SndEnvPtr:		.res	2
+
+;----------------------------------------------------------------------------
+; Global variables
+;
+
+	.bss
+
+SndRetAFlag2:		.res	1
+SndRetAFlag:		.res	1
+SndPtrLo:		.res	4
+SndPtrHi:		.res	4
+SndDelay:		.res	4
+SndLoopCnt:		.res	4
+SndLoopPtrLo:		.res	4
+SndLoopPtrHi:		.res	4
+SndVolume:		.res	4
+SndMaxVolume:		.res	4
+SndNotePlaying:		.res	4
+SndRetAddr:		.res	8
+SndActive:		.res	4
+SndReqStop:		.res	4
+SndEnvVol:		.res	4
+SndEnvFrq:		.res	4
+SndEnvWave:		.res	4
+SndChannel:		.res	32
+SndEnvVolCnt:		.res	4
+SndEnvVolInc:		.res	4
+SndEnvVolOff:		.res	4
+SndEnvVolLoop:		.res	4
+SndEnvVolParts:		.res	4
+SndEnvVolParts2:	.res	4
+SndEnvFrqCnt:		.res	4
+SndEnvFrqInc:		.res	4
+SndEnvFrqOff:		.res	4
+SndEnvFrqLoop:		.res	4
+SndEnvFrqParts:		.res	4
+SndEnvFrqParts2:	.res	4
+SndEnvWaveCnt:		.res	4
+SndEnvWaveOff:		.res	4
+SndEnvWaveLoop:		.res	4
+SndEnvWaveParts:	.res	4
+SndEnvWaveParts2:	.res	4
+
+MAX_INSTRUMENTS		.set	64
+SndEnvVolPtrLo:		.res	MAX_INSTRUMENTS
+SndEnvVolPtrHi:		.res	MAX_INSTRUMENTS
+SndEnvFrqPtrLo:		.res	MAX_INSTRUMENTS
+SndEnvFrqPtrHi:		.res	MAX_INSTRUMENTS
+SndEnvWavePtrLo:	.res	MAX_INSTRUMENTS
+SndEnvWavePtrHi:	.res	MAX_INSTRUMENTS
+
+	.rodata
+
+SndOffsets:		.byte	$00,$08,$10,$18
+
+	.code
+
+;----------------------------------------------------------------------------
+; void lynx_snd_init() will initialize the sound engine.
+;
+
+_31250Hz	.set	%101
+
+_lynx_snd_init:
+	php
+	sei
+	lda	#%10011000|_31250Hz
+	sta	STIMCTLA
+	lda	#129
+	sta	STIMBKUP	; set up a 240Hz IRQ
+
+	stz	AUD0VOL
+	stz	AUD1VOL
+	stz	AUD2VOL
+	stz	AUD3VOL
+
+	stz	$fd44		; all channels full volume / no attenuation
+	lda	#$ff
+	stz	MSTEREO
+
+	lda	#0
+	sta	AUD0CTLA
+	sta	AUD1CTLA
+	sta	AUD2CTLA
+	sta	AUD3CTLA
+
+	ldx	#3
+	lda	#0
+init0:	stz	SndActive,x
+	stz	SndReqStop,x
+	stz	SndEnvVol,x
+	stz	SndEnvFrq,x
+	stz	SndEnvWave,x
+	ldy	SndOffsets,x
+	sta	SndChannel+2,y
+	dex
+	bpl	init0
+	stz	SndRetAFlag
+	stz	SndRetAFlag2
+	stz	SndSema
+	plp
+	rts
+