From e51b5c8b599659b328ded874ec0f4805101fba03 Mon Sep 17 00:00:00 2001
From: cpg <cpg@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Fri, 23 Jun 2000 22:06:37 +0000
Subject: [PATCH] multiply by 40 routine

git-svn-id: svn://svn.cc65.org/cc65/trunk@118 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 libsrc/atari/mul40.s | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 libsrc/atari/mul40.s

diff --git a/libsrc/atari/mul40.s b/libsrc/atari/mul40.s
new file mode 100644
index 000000000..b14d960a0
--- /dev/null
+++ b/libsrc/atari/mul40.s
@@ -0,0 +1,35 @@
+;
+; Christian Groessler, June 2000
+;
+; mul40
+; multiplies A by 40 and returns result in AX
+; uses tmp4
+
+	.importzp	tmp4
+	.export		mul40
+
+.proc	mul40
+
+	ldx	#0
+	stx	tmp4
+	sta	loc_tmp
+	asl	a
+	rol	tmp4
+	asl	a
+	rol	tmp4		; val * 4
+	adc	loc_tmp
+	bcc	L1
+	inc	tmp4		; val * 5
+L1:	asl	a
+	rol	tmp4		; val * 10
+	asl	a
+	rol	tmp4
+	asl	a
+	rol	tmp4		; val * 40
+	ldx	tmp4
+	rts
+
+.endproc
+
+	.bss
+loc_tmp:.res	1