disk unit - 8.

	if	nhard gt 8
dph16	dw	0000h,0000h				; translate table.
	dw	0000h,0000h				; scratch area.
	dw	dpbh8				; disk parameter block.
	dw	00000h,0ffffh			; checksum, allocation.
	dw	0ffffh,0ffffh,0ffffh		; DIRBCB, DATBCB, TBLSEG.
	endif

	; hard disk unit - 9.

	if	nhard gt 9
dph17	dw	0000h,0000h				; translate table.
	dw	0000h,0000h				; scratch area.
	dw	dpbh9				; disk parameter block.
	dw	00000h,0ffffh			; checksum, allocation.
	dw	0ffffh,0ffffh,0ffffh		; DIRBCB, DATBCB, TBL	mov	byte ptr [bx],dmalcon	;load constants command.
	call	mwissue			; do load constants.
	push	ds			; save data segment.
	mov	dx,0			; ds = 0.
	mov	ds,dx
	mov	word ptr .chan,cx	; restore whatever was at 50,51.
	mov	byte ptr .chan+2,ah	; restore whatever was at 52.
	sti				; re-enable interrupts.
	pop	ds
	ret
;
; do the opration specified by a register.
;
mwprep:
	mov	byte ptr dmaop,al	;save command channel op code.
; do the operation specified by dmaop.
mwrdwr:
	mov	cl,band1
	mov	bx,word pv	al,bl
	cmp	al,dl
	ret
l_7	equ	$

	; bios stack area.
tmpsp	rw	1
	rw	40		; 20 levels.
tmp_tos	rw	0		; top of stack.

	; Morrow 5-inch Winchester Controller Scratch Area.
mwtab	rs	0		; collectionof track addresses.
	dw	0ffffh		; initialize to
	dw	0ffffh		; (way out on the end of disk.)
	dw	0ffffh
	dw	0ffffh
mwop	db	0
mwhead	db	0		; currently selected head.
mwsectr	rs	0
	db	0		; currently selected sector.
dmachan	equ	(offset $)	; command channel area.
dmasel0	db	0		; drive select.
dmastble.
	dw	0000h,0000h				; scratch area.
	dw	dpbh2				; disk parameter block.
	dw	00000h,0ffffh			; checksum, allocation.
	dw	0ffffh,0ffffh,0ffffh		; DIRBCB, DATBCB, TBLSEG.
	endif

	; hard disk unit - 3.

	if	nhard gt 3
dph11	dw	0000h,0000h				; translate table.
	dw	0000h,0000h				; scratch area.
	dw	dpbh3				; disk parameter block.
	dw	00000h,0ffffh			; checksum, allocation.
	dw	0ffffh,0ffffh,0ffffh		; DIRBCB, DATBCB, TBLSEG.
	endif

	; hard disk unit - 4.

	if	nhard gt 4
dph12	dw	0000hSEG.
	endif

	; hard disk unit - 10.

	if	nhard gt 10
dph18	dw	0000h,0000h				; translate table.
	dw	0000h,0000h				; scratch area.
	dw	dpbh10				; disk parameter block.
	dw	00000h,0ffffh			; checksum, allocation.
	dw	0ffffh,0ffffh,0ffffh		; DIRBCB, DATBCB, TBLSEG.
	endif

	; hard disk unit - 11.

	if	nhard gt 11
dph19	dw	0000h,0000h				; translate table.
	dw	0000h,0000h				; scratch area.
	dw	dpbh11				; disk parameter block.
	dw	00000h,0ffffh			; checksum, allocation.
	dw	0ffffh,0ffffhtr dmarg0
	mov	dx,precomp
	call	mwhlcde
	jb	mwpreps
	mov	cl,band2
	mov	dx,lowcurr
	call	mwhlcde
	jb	mwpreps
	mov	cl,band