XLIB	InvCase


; ******************************************************************************
;
; Invert character case to either upper	or lower case.
;
; Design & programming by Gunther Strube, Copyright (C) InterLogic 1995
;
;  IN:	A = ASCII	byte
; OUT:	A = converted ASCII	byte
;
; Registers changed	after return:
;
;	..BCDEHL/IXIY	same
;	AF....../....	different
;
.InvCase			CP	'['		; if	A <=	'Z'	&&
				JR	NC, check_lowercase
				CP	'A'		; if	A >=	'A'
				RET	C
				XOR	32		; inverse	case...
				RET
.check_lowercase	CP	'{'		; if	A <=	'z'	&&
				JR	NC, check_latin1
				CP	'a'		; if	A >=	'a'
				RET	C
				XOR	32		; inverse	case
				RET
.check_latin1		CP	$FF		; if	A <=	$FE	&&
				RET	Z
				CP	$C0		; if	A >=	$C0
				RET	C
				XOR	32		; then inverse	case
				RET