; ffhaslu.lib 1/22/2012 dwg - macro to detect drive with logical unit support

ffhaslu	macro	
	local	ret$false,fini
	mvi	c,RETCURR
	call	BDOS
	mov	c,a
	call	BISELDSK
	lxi	d,16		; offset to end of DPH
	dad	d		; calc offset of 1st signature byte
	mov	a,m		; pick up first sig byte which s/b 'L'
	cpi	'L'
	jnz	ret$false	; if it wasn't, indicate to caller no LU
	inx	h		; bump ptr to 2nd signature byte
	mov	a,m		; pick up second sig byte which s/b 'U'
	cpi	'U'
	jnz	ret$false	; if it wasn't, indicate to caller no LU
	mvi	a,TRUE		; otherwise indicate presence of LU support
	jmp	fini		; finish up macro
ret$false:
	mvi	a,FALSE		; prepare negative response for caller
fini:
	endm