Added the new toascii function for the CBMs.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4425 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm/toascii.s

@@ -0,0 +1,38 @@
+;
+; Ullrich von Bassewitz, 2009-11-02
+;
+; unsigned char __fastcall__ toascii (unsigned char c);
+; /* Convert a target specific character to ascii */
+;
+
+       	.export	       	_toascii
+
+        .macpack        generic
+
+.proc   _toascii
+
+; Check for code between 65 and 90
+
+        cmp     #$41
+        blt     @L1
+        cmp     #$5B
+        bge     @L1
+
+; Code between 65 and 90
+
+        ora     #$20
+        rts
+
+; Check for code between 193 and 219
+
+@L1:    cmp     #$C1
+        blt     @L9
+        cmp     #$DC
+        bge     @L9
+
+; Code between 193 and 219
+
+        and     #$7F
+@L9:    rts
+
+.endproc