megademo: more fussing with the loader

linker_scripts/apple2_2000.inc

@@ -1,10 +1,10 @@
 MEMORY {
        ZP: start = $00, size = $1A, type = rw;
-       RAM: start = $2000, size = $7E00, file = %O;
+       RAM: start = $2000, size = $A000, file = %O;
 }
 
 SEGMENTS {
-CODE: load = RAM, type = ro, align=$1000;
+CODE: load = RAM, type = ro, align=$100;
 RODATA: load = RAM, type = ro;
 DATA: load = RAM, type = rw;
 BSS: load = RAM, type = bss, define = yes;

megademo/Makefile

@@ -7,9 +7,10 @@ PNG_TO_RLE = ../gr-utils/png2rle
 
 all:	megademo.dsk
 
-megademo.dsk:	MEGADEMO MEGALOAD
+megademo.dsk:	MEGADEMO MEGALOAD c64.img
 	$(DOS33) -y megademo.dsk BSAVE -a 0x4000 MEGADEMO
 	$(DOS33) -y megademo.dsk BSAVE -a 0x800 MEGALOAD
+	$(DOS33) -y megademo.dsk BSAVE -a 0x2000 c64.img C64.IMG
 #	$(DOS33) -y megademo.dsk RAWWRITE -t 27 -s 0 MEGADEMO MEGA2
 #	$(DOS33) -y megademo.dsk BSAVE -a 0x4000 D_HGRC.BIN
 #	$(DOS33) -y megademo.dsk BSAVE -a 0x4000 FS_HGRC.BIN

megademo/c64_opener.s

@@ -24,24 +24,24 @@ c64_opener:
 	bit	HIRES			; hires mode !!!
 	bit	SET_GR			; graphics mode
 
-	lda	#<c64
-	sta	LZ4_SRC
-	lda	#>c64
-	sta	LZ4_SRC+1
+;	lda	#<c64
+;	sta	LZ4_SRC
+;	lda	#>c64
+;	sta	LZ4_SRC+1
 
-	lda	#<(c64_end-8)		; skip checksum at end
-	sta	LZ4_END
-	lda	#>(c64_end-8)		; skip checksum at end
-	sta	LZ4_END+1
+;	lda	#<(c64_end-8)		; skip checksum at end
+;	sta	LZ4_END
+;	lda	#>(c64_end-8)		; skip checksum at end
+;	sta	LZ4_END+1
 
 
 
-	lda	#<$2000
-	sta	LZ4_DST
-	lda	#>$2000
-	sta	LZ4_DST+1
+;	lda	#<$2000
+;	sta	LZ4_DST
+;	lda	#>$2000
+;	sta	LZ4_DST+1
 
-	jsr	lz4_decode
+;	jsr	lz4_decode
 
 
 	jsr	wait_until_keypress
@@ -370,11 +370,11 @@ done_c64:
 
 
 	;===================
-	; graphics
+	; c64 graphic, load at $2000-$4000 to start with
 	;===================
-c64:
-.incbin "c64.img.lz4",11
-c64_end:
+;c64:
+;.incbin "c64.img"
+;c64_end:
 
 
 ;=========================================================

megademo/megademo.s

@@ -6,6 +6,16 @@
 .include "hardware.inc"
 
 
+        ;===================
+        ; graphics
+        ;===================
+;c64:					; this should end up at $2000-$4000
+;.incbin "c64.img"
+;c64_end:
+
+
+real_start:				; this should end up at $4000
+
 	;===================
 	; Check for Apple II and patch
 	;===================
@@ -25,8 +35,6 @@ apple_iie:
 	;===================
 	jsr	HOME
 
-	jsr	waterfall
-
 	; C64 Opening Sequence
 
 	jsr	c64_opener
@@ -49,7 +57,7 @@ apple_iie:
 	; Leaving house
 
 	; Riding bird
-;	jsr	bird_mountain
+	jsr	bird_mountain
 
 	; Waterfall
 	jsr	waterfall
@@ -58,7 +66,7 @@ apple_iie:
 	jsr	rocket_takeoff
 
 	; mode7 (???)
-;	jsr	mode7_flying
+	jsr	mode7_flying
 
 	; Fly in space
 
@@ -66,7 +74,7 @@ apple_iie:
 
 	; Fireworks
 
-;	jsr	fireworks
+	jsr	fireworks
 
 	; Game over
 game_over_man:
@@ -95,11 +103,11 @@ loop_forever:
 .align $100
 	.include	"fireworks.s"
 	.include	"hgr.s"
-;	.include	"bird_mountain.s"
+	.include	"bird_mountain.s"
 	.include	"move_letters.s"
 .align $100
 	.include	"gr_putsprite.s"
-;	.include	"mode7.s"
+	.include	"mode7.s"
 	.include	"takeoff.s"
 	.include	"waterfall.s"
 

megademo/megaload.s

@@ -18,15 +18,30 @@
 	step	=	$fd	; state for stepper motor
 	tmptrk	=	$fe	; temporary copy of current track
 	phase	=	$ff	; current phase for /seek
-	dirbuf	=	$400
+
+	dirbuf	=	$1e00	; note, don't put this immediately below
+				;   the value being read as destaddr-4
+				;   is temporarily overwritten during read
+				;   process
+
+
+	; note also, can't load file bigger than $8000 (32k) in size?
+	; seems to break things?
 
 start:
 	jsr	init	; unhook DOS, init nibble table
 
 	; open and read a file
-	lda	#<file_to_read
+	lda	#<megademo_filename
 	sta	namlo
-	lda	#>file_to_read
+	lda	#>megademo_filename
+	sta	namhi
+	jsr	opendir		; open and read entire file into memory
+
+	; open and read a file
+	lda	#<c64_filename
+	sta	namlo
+	lda	#>c64_filename
 	sta	namhi
 	jsr	opendir		; open and read entire file into memory
 
@@ -34,12 +49,18 @@ start:
 
 
 ; filename to open is 30-character Apple text:
-file_to_read:	;.byte "MEGADEMO                      "
+megademo_filename:	;.byte "MEGADEMO                      "
 	.byte 'M'|$80,'E'|$80,'G'|$80,'A'|$80,'D'|$80,'E'|$80,'M'|$80,'O'|$80
 	.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
 	.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
 	.byte $A0,$A0,$A0,$A0,$A0,$A0
 
+c64_filename:	;.byte "C64.IMG                       "
+	.byte 'C'|$80,'6'|$80,'4'|$80,'.'|$80,'I'|$80,'M'|$80,'G'|$80,$A0
+	.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
+	.byte $A0,$A0,$A0,$A0,$A0,$A0,$A0,$A0
+	.byte $A0,$A0,$A0,$A0,$A0,$A0
+
 
                 ;unhook DOS and build nibble table
 
@@ -159,6 +180,7 @@ foundname:
 	lda	filbuf
 	sbc	#4
 	sta	adrlo
+
 	lda	filbuf+1
 	sbc	#0
 	sta	adrhi
@@ -183,6 +205,7 @@ L5:
 	adc	#3
 	sta	sizelo
 	sta	secsize
+
 	lda	filbuf+3
 	adc	#0
 	sta	sizehi
@@ -462,7 +485,7 @@ sectbl:	.byte $00,$0d,$0b,$09,$07,$05,$03,$01,$0e,$0c,$0a,$08,$06,$04,$02,$0f
 
 
 ; From $BA96 of DOS33
-nibtbl		= *
+nibtbl:	.res 128			;		= *
 ;	.byte	$00,$01,$98,$99,$02,$03,$9C,$04	; $BA96	; 00
 ;	.byte	$05,$06,$A0,$A1,$A2,$A4,$A4,$A5 ; $BA9E	; 08
 ;	.byte	$07,$08,$A8,$A9,$AA,$09,$0A,$0B ; $BAA6	; 10
@@ -481,7 +504,7 @@ nibtbl		= *
 ;	.byte	$00,$00,$00,$00,$00,$00,$00,$00
 
 
-bit2tbl         = nibtbl+128
-filbuf          = bit2tbl+86
-dataend         = filbuf+4
+bit2tbl:	.res 86			;	= nibtbl+128
+filbuf:		.res 4			;	= bit2tbl+86
+					;dataend         = filbuf+4