title	Module from library BASE_1 : HEXNIB
	name	('HEXNIB')
	maclib	baselib.lib

; Get hex nibble from ASCII character

; Copyright (C)	Werner Cirsovius
;		Hohe Weide 44
;		D-20253 Hamburg
;		Tel.: +49-40-4223247

;		Version 1.0 February 1987

; ENTRY	Reg pair <HL> points to ASCII buffer

; EXIT	Accu holds hex nibble
;	Buffer updated

	entry	hexnib

hexnib:
	ld	a,(hl)		; Get character
	inc	hl
	sub	asc		; Strip off offset
	cp	num		; Test range
	ret	c
	sub	hexrng		; Fix real hex
	ret

	end