X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=libsrc%2Fcommon%2Fisupper.s;h=b9d53a61470bee6de5b2a6c7bf465dc89be3433e;hb=6657214a18d41ce76e9ea1bc8b67977ee13d3645;hp=bb5ad07a2873f4e88f8ca588369059a5298cba69;hpb=53dd513176425872128ef26031d00952ef7a0628;p=cc65

diff --git a/libsrc/common/isupper.s b/libsrc/common/isupper.s
index bb5ad07a2..b9d53a614 100644
--- a/libsrc/common/isupper.s
+++ b/libsrc/common/isupper.s
@@ -5,11 +5,17 @@
 ;
 
 	.export		_isupper
-	.import		__ctype
+       	.include	"ctype.inc"
 
 _isupper:
+	cpx	#$00		; Char range ok?
+	bne	@L1		; Jump if no
 	tay
 	lda	__ctype,y	; Get character classification
-	and    	#$02   	       	; Mask upper char bit
+	and    	#CT_UPPER	; Mask upper char bit
+	rts
+
+@L1:	lda	#$00		; Return false
+	tax
 	rts