From 4ae00f4e9d93b334fd4c49e533783e5fc195cf3d Mon Sep 17 00:00:00 2001
From: Vince Weaver <vince@deater.net>
Date: Wed, 14 Feb 2018 00:41:23 -0500
Subject: [PATCH] mockingboard: work on lz4 decoder

---
 gr-sim/Makefile |  14 +++-
 gr-sim/l4d.c    | 204 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 216 insertions(+), 2 deletions(-)
 create mode 100644 gr-sim/l4d.c

diff --git a/gr-sim/Makefile b/gr-sim/Makefile
index a86bab26..8a18ff46 100644
--- a/gr-sim/Makefile
+++ b/gr-sim/Makefile
@@ -6,7 +6,8 @@ SDL_LIBS= `sdl-config --libs`
 SDL_INCLUDE= `sdl-config --cflags`
 
 all:	fade fixed_point rainbow sparkle starfield starfield_fixed kaleido \
-	tfv mode7_demo text text_demo tfv_multiply rasterbars rasterbars_fixed
+	tfv mode7_demo text text_demo tfv_multiply rasterbars rasterbars_fixed \
+	l4d
 
 
 #### Library
@@ -29,6 +30,14 @@ fade.o:	fade.c demo_title.c
 
 ####
 
+l4d:	l4d.o gr-sim.o tfv_utils.o gr_fast_clear.o
+	$(CC) $(LFLAGS) $(SDL_LIBS) -o l4d l4d.o gr-sim.o gr_fast_clear.o tfv_utils.o
+
+l4d.o:	l4d.c demo_title.c
+	$(CC) $(CFLAGS) -c l4d.c
+
+####
+
 fixed_point:	fixed_point.o
 	$(CC) $(LFLAGS) -o fixed_point fixed_point.o
 
@@ -211,6 +220,7 @@ gr-sim.o:	gr-sim.c gr-sim.h apple2_font.h
 clean:	
 	rm -f *~ *.o gr-sim rainbow sparkle starfield starfield_fixed kaleido \
 			tfv text mode7_demo fade fixed_point tfv_multiply \
-			rasterbars rasterbars_fixed lookup_tables text_demo
+			rasterbars rasterbars_fixed lookup_tables text_demo \
+			l4d
 
 
diff --git a/gr-sim/l4d.c b/gr-sim/l4d.c
new file mode 100644
index 00000000..1dd76ba7
--- /dev/null
+++ b/gr-sim/l4d.c
@@ -0,0 +1,204 @@
+#include <stdio.h>
+#include <string.h>
+
+#include "gr-sim.h"
+
+#define MAX_INPUT	65536
+static unsigned char input[MAX_INPUT];
+
+#define src	0x0
+#define dst	0x2
+#define end	0x4
+#define count	0x6
+#define delta	0x8
+#define A1L	0x3c
+#define A1H	0x3d
+#define A2L	0x3e
+#define A2H	0x3f
+#define A4L	0x42
+#define A4H	0x43
+
+static short s;
+
+void getsrc(void) {
+//getsrc:
+	a=ram[y_indirect(src,y)];		// lda 	(src), y
+	ram[src]++;				//inc	src
+	if (ram[src]!=0) goto done_getsrc;	//bne	+
+	ram[src+1]++;				//inc	src+1
+done_getsrc: ;
+	//+	rts
+}
+
+static void pha(void) {
+
+	s--;
+	ram[s]=a;
+}
+
+static void pla(void) {
+
+	a=ram[s];
+	s++;
+}
+
+void buildcount(void) {
+
+	int cnew,c;
+
+//buildcount:
+	x=1;					// ldx	#1
+	ram[count+1]=x; 			//stx	count+1
+	if (a!=0xf) goto done_buildcount;	//cmp	#$0f
+						//bne	++
+minus_buildcount:
+	ram[count]=a;				//-	sta	count
+	getsrc();				//jsr	getsrc
+	x=a;					//tax
+	c=0;					//clc
+	cnew=(a+ram[count]+c)>0xff;
+	a=a+ram[count]+c;			//adc	count
+	if (cnew) goto skip_buildcount;		// bcc	+
+	ram[count+1]++;				//inc	count+1
+skip_buildcount:
+	x++;					//+	inx
+	x&=0xf;
+	if (x==0) goto minus_buildcount;	//beq	-
+done_buildcount: ;				//++	rts
+}
+
+int main(int argc, char **argv) {
+
+	FILE *fff;
+	int size;
+	short orgoff,paksize,pakoff;
+
+	fff=fopen("../mockingboard/outi.raw.lz4","r");
+	if (fff==NULL) {
+		fprintf(stderr,"Error opening!\n");
+		return -1;
+	}
+
+	size=fread(input,sizeof(unsigned char),MAX_INPUT,fff);
+	printf("Read %d bytes\n",size);
+
+	fclose(fff);
+
+	memcpy(&ram[0x2000],input,size);
+
+	s=0x1ff;
+
+	//LZ4 data decompressor for Apple II
+	//Peter Ferrie (peter.ferrie@gmail.com)
+
+	//init	=	0 ;set to 1 if you know the values
+	//hiunp	=	0 ;unpacker entirely in high memory
+	//hipak	=	0 ;packed data entirely in high memory (requires hiunp)
+
+	//oep = 0; //first unpacked byte to run, you must set this by yourself
+	orgoff = 0x8000; //offset of first unpacked byte, you must set this by yourself
+	paksize	= size; //size of packed data, you must set this by yourself if hiunp=0
+	pakoff = 0x2000;
+
+
+//LCBANK2	=	$c083
+//MOVE	=	$fe2c
+
+	a=(pakoff&0xff);	//lda	#<pakoff ;packed data offset
+	ram[src]=a;		//sta	src
+	a=(pakoff+paksize)&0xff;//lda	#<(pakoff+paksize) ;packed data size
+	ram[end]=a;		// sta	end
+	a=(pakoff>>8);		//lda	#>pakoff
+	ram[src+1]=a;		//sta	src+1
+	a=(pakoff+paksize)>>8;	//lda	#>(pakoff+paksize)
+	ram[end+1]=a;		//	sta	end+1
+	a=(orgoff>>8);		//lda	#>orgoff ;original unpacked data offset
+	ram[dst+1]=a;		//sta	dst+1
+	a=(orgoff&0xff);	//lda	#<orgoff
+	ram[dst]=a;		// sta	dst
+
+unpack:				//;unpacker entrypoint
+	goto unpmain;		//	jmp	unpmain
+
+unpmain:
+	y=0;			//ldy	#0
+
+parsetoken:
+	getsrc();		// jsr	getsrc
+	pha();			// pha
+	a<<=1;			// lsr
+	a<<=1;			// lsr
+	a<<=1;			// lsr
+	a<<=1;			// lsr
+	a&=0xff;
+	if (a==0) goto copymatches; //beq	copymatches
+#if 0
+	jsr	buildcount
+	tax
+	jsr	docopy
+	lda	src
+	cmp	end
+	lda	src+1
+	sbc	end+1
+	bcs	done
+#endif
+copymatches:
+	getsrc();		//jsr	getsrc
+#if 0
+	sta	delta
+	jsr	getsrc
+	sta	delta+1
+	pla
+	and	#$0f
+	jsr	buildcount
+	clc
+	adc	#4
+	tax
+	bcc	+
+	inc	count+1
++	lda	src+1
+	pha
+	lda	src
+	pha
+	sec
+	lda	dst
+	sbc	delta
+	sta	src
+	lda	dst+1
+	sbc	delta+1
+	sta	src+1
+	jsr	docopy
+	pla
+	sta	src
+	pla
+	sta	src+1
+	jmp	parsetoken
+
+done
+	pla
+	rts
+
+docopy
+	jsr	getput
+	dex
+	bne	docopy
+	dec	count+1
+	bne	docopy
+	rts
+
+
+
+getput
+	jsr	getsrc
+
+putdst
+	sta 	(dst), y
+	inc	dst
+	bne	+
+	inc	dst+1
++	rts
+
+#endif
+
+	return 0;
+}