:	pop	bx			; make stack right.
	ret

; jump here if no alternate found.
alt2:
	mov	cx,word ptr hrdtrk
	call	mwseek			;do the seek.
	jc	mwexit			; exit if seek error.
	mov	al,byte ptr mwop	;get the operation.
	mov	byte ptr dmaop,al	;tell the controller.
	mov	al,byte ptr hrdsec	;get the requested sector.

; jump here if an alternate is found.
altfnd:	mov	cl,al			;put in c.
	mov	dh,0			;clear head counter.
seclp:	sub	al,hrdspt		;subtract out a heads worth.
	jb	secfnd			;jump if found.
	inc	dh	word ptr dmarg0,cx	; set command channel cyl no.
	mov	al,dh
	inc	al
	mov	bx,0ffffh
	jnz	mwskip0
	mov	cl,stepout
	jmps	mwskip
mwskip0:
	mov	bx,cx			; bx=new track, dx = old track.
	sub	bx,dx			; bx = new track - old track.
	mov	cl,stepout		; cl = step out code.
	jc	mwsout			; hop if new track smaller.
	mov	cl,stepin		; else cl = code to step in.
	jmps	mwskip
mwsout:
	call	mwnegh1
mwskip:
	mov	dmastep,bx		; save step count.
	mov	al,hrddsk		; al = physical hard disk number.
	or	al,cl
	mov	du	$
	cseg
	org	offset l_2

	; External Entry Point to Read/Write Routine.
	; Read or Write the number of sectors indicated.
	; Note:  assumes all are on the same cylinder.
	; nosecs = number of sectors to transfer.
	; sector = starting sector number.
	; track  = track number.
	; sekdsk  = disk number (0-7 are floppies, 8-15 are hard disk).
	; lsb20  = least significant word of 20-bit transfer address.
	; msb20  = most significant byte of 20-bit transfer address.
	; oper   = 1 for read, 2 for wrhard disk r/w routine.


	; Common Morrow hard disk read/write routine.
mwtran:
	mov	cl,hrddsk		; get hard disk number.
	mov	bx,(offset badmap)	;get badmap address.
all:
	mov	dx,word ptr badptr	;get bad map pointer.
	or	al,al			;clear carry.
	xch