From da37bbf9a15bf5aa8e9fc7e0e123abc231733cdf Mon Sep 17 00:00:00 2001
From: Vince Weaver <vincent.weaver@maine.edu>
Date: Thu, 4 Nov 2021 14:06:52 -0400
Subject: [PATCH] tiny_music: optimize some more

---
 demos/tiny_music/Makefile             |  2 +-
 demos/tiny_music/mockingboard_setup.s | 52 +++++++++++----------------
 demos/tiny_music/music.s              |  5 +--
 demos/tiny_music/nozp.inc             | 27 --------------
 demos/tiny_music/yankee_music.s       |  8 +++++
 5 files changed, 30 insertions(+), 64 deletions(-)
 delete mode 100644 demos/tiny_music/nozp.inc

diff --git a/demos/tiny_music/Makefile b/demos/tiny_music/Makefile
index 10a16844..607d0051 100644
--- a/demos/tiny_music/Makefile
+++ b/demos/tiny_music/Makefile
@@ -26,7 +26,7 @@ MUSIC:	music.o
 	ld65 -o MUSIC music.o -C $(LINKER_SCRIPTS)/apple2_2000.inc
 
 music.o:	music.s \
-	zp.inc hardware.inc nozp.inc \
+	zp.inc hardware.inc \
 	yankee_music.s \
 	interrupt_handler.s mockingboard_setup.s
 	ca65 -o music.o music.s -l music.lst
diff --git a/demos/tiny_music/mockingboard_setup.s b/demos/tiny_music/mockingboard_setup.s
index 67502722..67385e1d 100644
--- a/demos/tiny_music/mockingboard_setup.s
+++ b/demos/tiny_music/mockingboard_setup.s
@@ -151,45 +151,33 @@ mockingboard_setup_interrupt:
 	sta	MOCK_6522_ORB2
 
 init_registers:
+
+	; init song data
+
 	lda	#0
 	sta	SONG_OFFSET
 	sta	SONG_COUNTDOWN
 
-	; set fine note A
+	; read 14 bytes from beginning of song to init
 
-	ldx	#$00
-	lda	#$00
+	ldx	#13
+init_loop:
+init_smc:
+	txa
+	tay
+	lda	(SONG_L),Y
 	jsr	ay3_write_reg
+	dex
+	bne	init_loop
 
-	; set coarse note A
-
-	ldx	#$01
-	lda	#$00
-	jsr	ay3_write_reg
-
-	; set mixer ABC enabled
-
-	ldx	#$07
-	lda	#$38
-	jsr	ay3_write_reg
-
-	; A volume 14
-
-	ldx	#$08
-	lda	#$E
-	jsr	ay3_write_reg
-
-	; B volume 12
-
-	ldx	#$09
-	lda	#$C
-	jsr	ay3_write_reg
-
-	; C volume 12
-
-	ldx	#$0A
-	lda	#$C
-	jsr	ay3_write_reg
+	; update SONG_L to point to beginning
+	lda	SONG_L
+	clc
+	adc	#14
+	sta	SONG_L
+	bcc	no_oflo
+	inc	SONG_H
+no_oflo:
 
 	rts
 
diff --git a/demos/tiny_music/music.s b/demos/tiny_music/music.s
index 4b8e48f5..1b925640 100644
--- a/demos/tiny_music/music.s
+++ b/demos/tiny_music/music.s
@@ -2,14 +2,13 @@
 
 ; 514B -- Initial implementation
 ; 423B -- inline everything
+; 400B -- put register init at end of song
 
 SONG_L	= $70
 SONG_H	= $71
 SONG_OFFSET = $72
 SONG_COUNTDOWN = $73
 
-
-
 ; proposed format
 ; CCOONNNN -- c=channel, o=octave, n=note
 ; 11LLLLLL -- L=length
@@ -51,6 +50,4 @@ forever:
 .include        "mockingboard_setup.s"
 .include        "interrupt_handler.s"
 
-	.include "nozp.inc"
-
 	.include "yankee_music.s"
diff --git a/demos/tiny_music/nozp.inc b/demos/tiny_music/nozp.inc
deleted file mode 100644
index 239a25c1..00000000
--- a/demos/tiny_music/nozp.inc
+++ /dev/null
@@ -1,27 +0,0 @@
-;; Things that normally would go in the zero page
-
-
-AY_REGISTERS:
-A_FINE_TONE:	.byte $00
-A_COARSE_TONE:	.byte $00
-B_FINE_TONE:	.byte $00
-B_COARSE_TONE:	.byte $00
-C_FINE_TONE:	.byte $00
-C_COARSE_TONE:	.byte $00
-NOISE:		.byte $00
-ENABLE:
-PT3_MIXER_VAL:	.byte $00
-A_VOLUME:	.byte $00
-B_VOLUME:	.byte $00
-C_VOLUME:	.byte $00
-ENVELOPE_FINE:	.byte $00
-ENVELOPE_COARSE:.byte $00
-ENVELOPE_SHAPE:	.byte $00
-
-LOOP:		.byte $00
-MB_VALUE:	.byte $00
-DONE_PLAYING:	.byte $00
-DONE_SONG:	.byte $00
-PT3_TEMP:	.byte $00
-
-
diff --git a/demos/tiny_music/yankee_music.s b/demos/tiny_music/yankee_music.s
index 6ebe061d..c5d39612 100644
--- a/demos/tiny_music/yankee_music.s
+++ b/demos/tiny_music/yankee_music.s
@@ -6,6 +6,14 @@
 	; 11LLLLLL -- L=length	1/32=1, 1/16=2, 1/8=4, 1/4=8 1/2=16 1=32
 
 yankee_doodle_song:
+
+; register init
+	.byte	$00,$00,$00,$00,$00,$00		; $00: A/B/C fine/coarse
+	.byte	$00				; $06
+	.byte	$38				; $07 mixer (ABC on)
+	.byte	$0E,$0C,$0C			; $08 volume A/B/C
+	.byte	$00,$00,$00,$00			; $09
+; music
 	.byte	$17	;00 01 0111	G3 1/4
 	.byte	$4B	;01 00 1011	B2 1
 	.byte	$87	;10 00 0111	G2 1