From 7d731dce0246a7e47ebcc922c3371e88c999598e Mon Sep 17 00:00:00 2001
From: uz <uz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Mon, 1 Feb 2010 18:04:14 +0000
Subject: [PATCH] Marco van den Heuvel contributed code to detect a C64 DTV.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4570 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 libsrc/c64/get_ostype.s | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/libsrc/c64/get_ostype.s b/libsrc/c64/get_ostype.s
index e2db72ae2..4058e116e 100644
--- a/libsrc/c64/get_ostype.s
+++ b/libsrc/c64/get_ostype.s
@@ -1,6 +1,9 @@
 ;
 ; Stefan Haubenthal, Jul 10 2003
 ;
+; C64DTV detection by
+; Marco van den Heuvel, 2010-01-28
+;
 ; unsigned char get_ostype(void)
 ;
 ; $AA US
@@ -8,16 +11,33 @@
 ; $43 SX-64
 ; $03 EU_NEW
 ; $00 EU_OLD
+; $FF C64DTV
 ;
 
 	.export		_get_ostype
 
 .proc	_get_ostype
 
-        ldx     #$00            ; Clear high byte
-	lda	$ff80
-	rts
+	ldx 	#0            ; Clear high byte
 
-.endproc
+       	ldy	#1
+	sty	$d03f
+	ldy	$d040
+	cpy	$d000
+	bne	@c64dtv
+	inc	$d000
+	cpy	$d040
+	beq	@c64dtv
+
+; Normal C64
 
+	lda 	$ff80
+	rts
+
+; C64 DTV
 
+@c64dtv:
+       	stx	$d03f
+	lda	#$ff
+	rts
+.endproc
-- 
2.39.5