-/* special constants for old ISO-8859-1 character byte values */
-#define CHAR_BYTE_UMLAUT_A (0xc4)
-#define CHAR_BYTE_UMLAUT_O (0xd6)
-#define CHAR_BYTE_UMLAUT_U (0xdc)
-#define CHAR_BYTE_UMLAUT_a (0xe4)
-#define CHAR_BYTE_UMLAUT_o (0xf6)
-#define CHAR_BYTE_UMLAUT_u (0xfc)
-#define CHAR_BYTE_SHARP_S (0xdf)
-#define CHAR_BYTE_COPYRIGHT (0xa9)
-#define CHAR_BYTE_REGISTERED (0xae)
-#define CHAR_BYTE_DEGREE (0xb0)
-#define CHAR_BYTE_CURSOR (0xa0)
-
-/* special character mapping for default fonts */
+// special constants for old ISO-8859-1 character byte values
+#define CHAR_BYTE_UMLAUT_A ((char)0xc4)
+#define CHAR_BYTE_UMLAUT_O ((char)0xd6)
+#define CHAR_BYTE_UMLAUT_U ((char)0xdc)
+#define CHAR_BYTE_UMLAUT_a ((char)0xe4)
+#define CHAR_BYTE_UMLAUT_o ((char)0xf6)
+#define CHAR_BYTE_UMLAUT_u ((char)0xfc)
+#define CHAR_BYTE_SHARP_S ((char)0xdf)
+#define CHAR_BYTE_COPYRIGHT ((char)0xa9)
+#define CHAR_BYTE_REGISTERED ((char)0xae)
+#define CHAR_BYTE_DEGREE ((char)0xb0)
+#define CHAR_BYTE_CURSOR ((char)0xa0)
+
+// special character mapping for default fonts