Add XZIP interpreter revision C.

Makefile

@@ -12,7 +12,8 @@ all: zip1.lst  zip1.bin  zip1-check \
      ezip2c.lst ezip2c.bin ezip2c-check \
      ezip2d.lst ezip2d.bin ezip2d-check \
      ezip2h.lst ezip2h.bin ezip2h-check \
-     xzip2a.lst xzip2a.bin xzip2a-check
+     xzip2a.lst xzip2a.bin xzip2a-check \
+     xzip2c.lst xzip2c.bin xzip2a-check
 
 
 %.p %.lst: %.asm
@@ -169,6 +170,16 @@ xzip2a-check: xzip2a.bin
 	echo "9aaf97852fd38f0015248074e88e3b1045602cbf8d01bb11d489e0687dc5287d xzip2a.bin" | sha256sum -c
 
 
+xzip2c.p xzip2c.lst: xzip.asm
+	asl xzip.asm -o xzip2c.p -L -OLIST xzip2c.lst -D iver='$$0503'
+
+xzip2c.bin: xzip2c.p
+	p2bin -r '$$d000-$$feff' xzip2c.p
+
+xzip2c-check: xzip2c.bin
+	echo "cc255dcc4d0960482a7e65927c8e8aa8f5de5831710c7bbc65dcb69689f4d208 xzip2c.bin" | sha256sum -c
+
+
 clean:
 	rm -f zip{1,2,3,3a,3b}.{p,lst,bin}
 	rm -f ezip2{a,b,c,d,h}.{p,lst,bin}

README.md

@@ -109,9 +109,9 @@ There were five revisions of the Apple II XZIP interpreter, A, C, E,
 F, and H. The platform number will be reported as 2, except when using
 an Apple IIc, which will be reported as 9.
 
-Early work on reverse-engineering XZIP interpreter revision A is
-present in the source file "ezip.asm". This does not use an include
-file for macro definitions.
+Early work on reverse-engineering XZIP interpreter revisions A and C
+are present in the source file "xzip.asm". This does not use an
+include file for macro definitions.
 
 ## YZIP
 

xzip.asm

@@ -6092,6 +6092,12 @@ new_line:
 	bne	.fwd2
 	lda	wndtop
 	sta	Zda
+
+	if	iver>=iver_c
+	inc	Zda
+	inc	Zda
+	endif
+
 	bit	kbd_strb
 	lda	hdr_unknown_29
 	sta	D057b
@@ -6586,7 +6592,11 @@ Sfada:	jsr	Sf8e1
 	sta	Dfdf0
 	ldy	wndtop
 	sty	Zda
+
+	if	iver==iver_a
 	inc	Zda
+	endif
+
 	tay
 	lda	(Zc8),y
 	cmp	#$4f
@@ -6614,7 +6624,13 @@ Sfada:	jsr	Sf8e1
 	beq	.fwd10
 	jmp	.fwd11
 
-.fwd4:	cmp	#$0d
+.fwd4:
+	if	iver>=iver_c
+	tay
+	bmi	.fwd9
+	endif
+
+	cmp	#$0d
 	beq	.fwd10
 	cmp	#$7f
 	beq	.fwd8
@@ -6658,6 +6674,11 @@ Sfada:	jsr	Sf8e1
 .fwd10:	sta	Dfdf0
 	lda	#$8d
 	jsr	Sdb39
+
+	if	iver>=iver_c
+	inc	Zda
+	endif
+
 	lda	Zd9
 	beq	.fwd11
 	lda	hdr_flags2+1
@@ -6845,6 +6866,11 @@ op_read_char:
 	jsr	Sf8e1
 	lda	wndtop
 	sta	Zda
+
+	if	iver>=iver_c
+	inc	Zda
+	endif
+
 	lda	#$00
 	sta	Zd6
 	sta	Z6e