.title	maskit
;
;	integer*2 function maskit(type, mask, value)
;	logical*1 function maskit(type, mask, value)
;
;	performs an and function of mask on value and returns
;	it as a 16-bit integer.  type indicates the type of operands,
;	with 0 indicating bytes or 1 indicating words
;
;
ap=%5					; argument pointer
type=2
mask=4
value=6
maskit::
	tst	@type(ap)		; see if byte or word
	bne	doword			; != 0 => words
dobyte:
	movb	@mask(ap),r1		; place mask in r1
	movb	@value(ap),r0		; place value to mask in r0
	br	domask
doword:
	mov	@mask(ap),r1
	mov	@value(ap),r0
domask:
	com	r1			; complement mask word
	bic	r1,r0			; clear all bits in r0 which are set
					; in r1
	return
	.end