From fad5af7ac2465ffc1c6577f13ea2796d93dd0465 Mon Sep 17 00:00:00 2001
From: Vince Weaver <vincent.weaver@maine.edu>
Date: Tue, 20 Apr 2021 16:30:05 -0400
Subject: [PATCH] text: move

---
 textmode/textscroll/Makefile  | 31 ++++++++++++++
 textmode/textscroll/hello.bas |  2 +
 textmode/textscroll/move.s    | 80 +++++++++++++++++++++++++++++++++++
 3 files changed, 113 insertions(+)
 create mode 100644 textmode/textscroll/Makefile
 create mode 100644 textmode/textscroll/hello.bas
 create mode 100644 textmode/textscroll/move.s

diff --git a/textmode/textscroll/Makefile b/textmode/textscroll/Makefile
new file mode 100644
index 00000000..f4cfffd7
--- /dev/null
+++ b/textmode/textscroll/Makefile
@@ -0,0 +1,31 @@
+include ../../Makefile.inc
+
+DOS33 = ../../utils/dos33fs-utils/dos33
+TOKENIZE = ../../utils/asoft_basic-utils/tokenize_asoft
+LINKERSCRIPTS = ../../linker_scripts
+EMPTYDISK = ../../empty_disk/empty.dsk
+
+all:	textscroll.dsk
+
+textscroll.dsk:	HELLO MOVE
+	cp $(EMPTYDISK) textscroll.dsk
+	$(DOS33) -y textscroll.dsk SAVE A HELLO
+	$(DOS33) -y textscroll.dsk BSAVE -a 0xC00 MOVE
+
+###
+
+HELLO:	hello.bas
+	$(TOKENIZE) < hello.bas > HELLO
+
+###
+
+MOVE: move.o
+	ld65 -o MOVE move.o -C $(LINKERSCRIPTS)/apple2_c00.inc
+
+move.o:       move.s
+	ca65 -o move.o move.s -l move.lst
+
+####
+
+clean:	
+	rm -f *~ *.o *.lst HELLO MOVE
diff --git a/textmode/textscroll/hello.bas b/textmode/textscroll/hello.bas
new file mode 100644
index 00000000..133a44bb
--- /dev/null
+++ b/textmode/textscroll/hello.bas
@@ -0,0 +1,2 @@
+5 HOME
+10 PRINT CHR$(4);"CATALOG"
diff --git a/textmode/textscroll/move.s b/textmode/textscroll/move.s
new file mode 100644
index 00000000..56236135
--- /dev/null
+++ b/textmode/textscroll/move.s
@@ -0,0 +1,80 @@
+
+CH	= $24
+CV	= $25
+
+
+HGR		= $F3E2
+SETTXT		= $FB39
+TABV		= $FB5B		; store A in CV and call MON_VTAB
+STORADV		= $FBF0		; store A at (BASL),CH, advancing CH, trash Y
+MON_VTAB	= $FC22		; VTAB to CV
+VTABZ		= $FC24		; VTAB to value in A
+HOME		= $FC58
+
+COUT	= $FDED
+COUT1	= $FDF0
+COUTZ	= $FDF6		; cout but ignore inverse flag
+
+ypos	= $2000
+xpos	= $2100
+
+move:
+	jsr	HGR
+	jsr	SETTXT
+
+
+next_frame:
+	ldx	#0
+next_text:
+	lda	xpos,X
+	bne	not_new
+
+new_text:
+	lda	#30
+	sta	xpos,X
+
+	txa
+	sta	ypos,X
+
+
+
+not_new:
+	lda	xpos,X
+	sta	CH
+	lda	ypos,X
+	sta	CV
+
+	jsr	MON_VTAB
+
+	txa
+	pha
+
+	ldx	#0
+big_loop:
+	lda	text,X
+
+	bmi	big_done
+
+	ora	#$80
+	jsr	STORADV
+	inx
+	bne	big_loop
+
+big_done:
+
+	pla
+	tax
+
+	dec	xpos,X
+
+	inx
+	cpx	#20
+	bne	next_text
+
+	jsr	HOME
+
+	jmp	next_frame
+
+text:
+	.byte "HELL",'O'|$80
+