Added helper macro to unset any mapped characters

lib/bbc.h.6502

@@ -80,3 +80,78 @@ MODE7_graphic_black = 144
 MODE7_contiguous = 153
 MODE7_separated = 154
 
+\\ Macro to reset any mapped characters
+\\ since BeebASM doesn't have any feature for this
+MACRO RESET_MAPCHAR
+
+	MAPCHAR 'A', 'A' 
+	MAPCHAR 'B', 'B'
+	MAPCHAR 'C', 'C'
+	MAPCHAR 'D', 'D'
+	MAPCHAR 'E', 'E'
+	MAPCHAR 'F', 'F'
+	MAPCHAR 'G', 'G'
+	MAPCHAR 'H', 'H'
+	MAPCHAR 'I', 'I'
+	MAPCHAR 'J', 'J'
+	MAPCHAR 'K', 'K'
+	MAPCHAR 'L', 'L'
+	MAPCHAR 'M', 'M'
+ 	MAPCHAR 'N', 'N'
+	MAPCHAR 'O', 'O'
+	MAPCHAR 'P', 'P'
+	MAPCHAR 'Q', 'Q'
+	MAPCHAR 'R', 'R'
+	MAPCHAR 'S', 'S'
+	MAPCHAR 'T', 'T'
+	MAPCHAR 'U', 'U'
+	MAPCHAR 'V', 'V'
+	MAPCHAR 'W', 'W'
+	MAPCHAR 'X', 'X'
+	MAPCHAR 'Y', 'Y'
+	MAPCHAR 'Z', 'Z'
+
+	MAPCHAR 'a', 'a'
+	MAPCHAR 'b', 'b'
+	MAPCHAR 'c', 'c'
+	MAPCHAR 'd', 'd'
+	MAPCHAR 'e', 'e'
+	MAPCHAR 'f', 'f'
+	MAPCHAR 'g', 'g'
+	MAPCHAR 'h', 'h'
+	MAPCHAR 'i', 'i'
+	MAPCHAR 'j', 'j'
+	MAPCHAR 'k', 'k'
+	MAPCHAR 'l', 'l'
+	MAPCHAR 'm', 'm'
+ 	MAPCHAR 'n', 'n'
+	MAPCHAR 'o', 'o'
+	MAPCHAR 'p', 'p'
+	MAPCHAR 'q', 'q'
+	MAPCHAR 'r', 'r'
+	MAPCHAR 's', 's'
+	MAPCHAR 't', 't'
+	MAPCHAR 'u', 'u'
+	MAPCHAR 'v', 'v'
+	MAPCHAR 'w', 'w'
+	MAPCHAR 'x', 'x'
+	MAPCHAR 'y', 'y'
+	MAPCHAR 'z', 'z'
+
+	MAPCHAR '0', '0'
+	MAPCHAR '1', '1'
+	MAPCHAR '2', '2'
+	MAPCHAR '3', '3'
+	MAPCHAR '4', '4'
+	MAPCHAR '5', '5'
+	MAPCHAR '6', '6'
+	MAPCHAR '7', '7'
+	MAPCHAR '8', '8'
+	MAPCHAR '9', '9'
+	MAPCHAR '?', '?'
+	MAPCHAR '!', '!'
+	MAPCHAR '.', '.'
+
+	MAPCHAR ' ', ' '
+
+ENDMACRO