;	TITLE	"SISGRAPH - Syslib 4.0"
	NAME	('ISGRAP')
;=================================================================
;   The Libraries, Version 4, (C) 1989 by Alpha Systems Corp.
;-----------------------------------------------------------------
; Author  : Harold F. Bower
;		Derived from SISGRAPH.Z80 Ver 1.1 by Richard Conn
; Date    : 28 Jul 89
; Version : 1.3
; Module  : SISGRAPH
; Abstract: This module contains only the routine ISGRAPH which
;	evaluates the character in register A and returns with
;	the Zero Flag Set (Z) if the character is a printable
;	ASCII char (i.e. in the range of 20H-7EH with the MSB
;	of an 8-bit byte masked).  If the character is in the
;	range of 0-1FH or 7FH, the Zero Flag is Reset (NZ).
; Revision:
;- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
; Module Entry Points:

	PUBLIC		ISGRAPH

	.Z80
	CSEG
;=========================================================================
; NAME - ISGRAPH
; Entry: A = Character to evaluate
; Exit : A = Char, Zero Flag Set (Z) if printable (20-7EH), else Reset (NZ)
; Uses : F
; Special Requirements:  None
;=========================================================================

ISGRAPH: PUSH	BC		; Save BC
	LD	C,A		; Save char in C
	AND	7FH		; Mask out MSB
	CP	' '+1		; Less than or equal to space?
	JR	C,NO
	CP	7FH		; Less than Delete?
	JR	NZ,YES
NO:	DEFB	0F6H		; Set NO response with "OR  0AFH"
YES:	XOR	A		; Set Flag
	LD	A,C		; Get char
	POP	BC		; Restore BC
	RET

	END