diff --git a/sys/dev/isa/fd.c b/sys/dev/isa/fd.c
index c181762cfb04..7d5b7e01d6fa 100644
--- a/sys/dev/isa/fd.c
+++ b/sys/dev/isa/fd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: fd.c,v 1.6 2000/06/28 16:27:53 mrg Exp $	*/
+/*	$NetBSD: fd.c,v 1.7 2000/07/06 02:02:48 thorpej Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -524,7 +524,7 @@ void
 fdstrategy(bp)
 	register struct buf *bp;	/* IO operation to perform */
 {
-	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(bp->b_dev)];
+	struct fd_softc *fd = device_lookup(&fd_cd, FDUNIT(bp->b_dev));
 	int sz;
  	int s;
 
@@ -765,16 +765,13 @@ fdopen(dev, flags, mode, p)
 	int mode;
 	struct proc *p;
 {
- 	int unit;
 	struct fd_softc *fd;
 	struct fd_type *type;
 
-	unit = FDUNIT(dev);
-	if (unit >= fd_cd.cd_ndevs)
-		return ENXIO;
-	fd = fd_cd.cd_devs[unit];
-	if (fd == 0)
-		return ENXIO;
+	fd = device_lookup(&fd_cd, FDUNIT(dev));
+	if (fd == NULL)
+		return (ENXIO);
+
 	type = fd_dev_to_type(fd, dev);
 	if (type == NULL)
 		return ENXIO;
@@ -798,7 +795,7 @@ fdclose(dev, flags, mode, p)
 	int mode;
 	struct proc *p;
 {
-	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
+	struct fd_softc *fd = device_lookup(&fd_cd, FDUNIT(dev));
 
 	fd->sc_flags &= ~FD_OPEN;
 	fd->sc_opts &= ~(FDOPT_NORETRY|FDOPT_SILENT);
@@ -1270,7 +1267,7 @@ fdioctl(dev, cmd, addr, flag, p)
 	int flag;
 	struct proc *p;
 {
-	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
+	struct fd_softc *fd = device_lookup(&fd_cd, FDUNIT(dev));
 	struct fdformat_parms *form_parms;
 	struct fdformat_cmd *form_cmd;
 	struct ne7_fd_formb fd_formb;
@@ -1443,7 +1440,7 @@ fdformat(dev, finfo, p)
 	struct proc *p;
 {
 	int rv = 0, s;
-	struct fd_softc *fd = fd_cd.cd_devs[FDUNIT(dev)];
+	struct fd_softc *fd = device_lookup(&fd_cd, FDUNIT(dev));
 	struct fd_type *type = fd->sc_type;
 	struct buf *bp;
 
diff --git a/sys/dev/isa/mcd.c b/sys/dev/isa/mcd.c
index c0d5a7bb5f25..9a6c30db78a9 100644
--- a/sys/dev/isa/mcd.c
+++ b/sys/dev/isa/mcd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: mcd.c,v 1.66 2000/03/23 07:01:35 thorpej Exp $	*/
+/*	$NetBSD: mcd.c,v 1.67 2000/07/06 02:02:48 thorpej Exp $	*/
 
 /*
  * Copyright (c) 1993, 1994, 1995 Charles M. Hannum.  All rights reserved.
@@ -318,15 +318,11 @@ mcdopen(dev, flag, fmt, p)
 	int flag, fmt;
 	struct proc *p;
 {
-	int error;
-	int unit, part;
+	int error, part;
 	struct mcd_softc *sc;
 
-	unit = MCDUNIT(dev);
-	if (unit >= mcd_cd.cd_ndevs)
-		return ENXIO;
-	sc = mcd_cd.cd_devs[unit];
-	if (!sc)
+	sc = device_lookup(&mcd_cd, MCDUNIT(dev));
+	if (sc == NULL)
 		return ENXIO;
 
 	if ((error = mcdlock(sc)) != 0)
@@ -424,7 +420,7 @@ mcdclose(dev, flag, fmt, p)
 	int flag, fmt;
 	struct proc *p;
 {
-	struct mcd_softc *sc = mcd_cd.cd_devs[MCDUNIT(dev)];
+	struct mcd_softc *sc = device_lookup(&mcd_cd, MCDUNIT(dev));
 	int part = MCDPART(dev);
 	int error;
 	
@@ -460,7 +456,7 @@ void
 mcdstrategy(bp)
 	struct buf *bp;
 {
-	struct mcd_softc *sc = mcd_cd.cd_devs[MCDUNIT(bp->b_dev)];
+	struct mcd_softc *sc = device_lookup(&mcd_cd, MCDUNIT(bp->b_dev));
 	struct disklabel *lp = sc->sc_dk.dk_label;
 	daddr_t blkno;
 	int s;
@@ -601,7 +597,7 @@ mcdioctl(dev, cmd, addr, flag, p)
 	int flag;
 	struct proc *p;
 {
-	struct mcd_softc *sc = mcd_cd.cd_devs[MCDUNIT(dev)];
+	struct mcd_softc *sc = device_lookup(&mcd_cd, MCDUNIT(dev));
 	int error;
 	int part;
 	
diff --git a/sys/dev/isa/satlink.c b/sys/dev/isa/satlink.c
index 904fdffc2832..afa197cbe156 100644
--- a/sys/dev/isa/satlink.c
+++ b/sys/dev/isa/satlink.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: satlink.c,v 1.10 2000/05/15 23:56:49 thorpej Exp $	*/
+/*	$NetBSD: satlink.c,v 1.11 2000/07/06 02:02:49 thorpej Exp $	*/
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -224,11 +224,11 @@ satlinkopen(dev, flags, fmt, p)
 	int flags, fmt;
 	struct proc *p;
 {
-	int error, unit = minor(dev);
 	struct satlink_softc *sc;
+	int error;
 
-	if (unit >= satlink_cd.cd_ndevs ||
-	    (sc = satlink_cd.cd_devs[unit]) == NULL)
+	sc = device_lookup(&satlink_cd, minor(dev));
+	if (sc == NULL)
 		return (ENXIO);
 
 	if (sc->sc_flags & SATF_ISOPEN)
@@ -260,8 +260,7 @@ satlinkclose(dev, flags, fmt, p)
 	int flags, fmt;
 	struct proc *p;
 {
-	int unit = minor(dev);
-	struct satlink_softc *sc = satlink_cd.cd_devs[unit];
+	struct satlink_softc *sc = device_lookup(&satlink_cd, minor(dev));
 	int s;
 
 	s = splsoftclock();
@@ -280,8 +279,7 @@ satlinkread(dev, uio, flags)
 	struct uio *uio;
 	int flags;
 {
-	int unit = minor(dev);
-	struct satlink_softc *sc = satlink_cd.cd_devs[unit];
+	struct satlink_softc *sc = device_lookup(&satlink_cd, minor(dev));
 	int error, s, count, sptr;
 	int wrapcnt, oresid;
 
@@ -366,8 +364,7 @@ satlinkioctl(dev, cmd, data, flags, p)
 	int flags;
 	struct proc *p;
 {
-	int unit = minor(dev);
-	struct satlink_softc *sc = satlink_cd.cd_devs[unit];
+	struct satlink_softc *sc = device_lookup(&satlink_cd, minor(dev));
 
 	switch (cmd) {
 	case SATIORESET:
@@ -394,8 +391,7 @@ satlinkpoll(dev, events, p)
 	int events;
 	struct proc *p;
 {
-	int unit = minor(dev);
-	struct satlink_softc *sc = satlink_cd.cd_devs[unit];
+	struct satlink_softc *sc = device_lookup(&satlink_cd, minor(dev));
 	int s, revents;
 
 	revents = events & (POLLOUT | POLLWRNORM);
diff --git a/sys/dev/isa/seagate.c b/sys/dev/isa/seagate.c
index a66edfc97e28..197c937ff3ff 100644
--- a/sys/dev/isa/seagate.c
+++ b/sys/dev/isa/seagate.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: seagate.c,v 1.37 2000/05/03 21:20:07 mycroft Exp $	*/
+/*	$NetBSD: seagate.c,v 1.38 2000/07/06 02:02:49 thorpej Exp $	*/
 
 /*
  * ST01/02, Future Domain TMC-885, TMC-950 SCSI driver
@@ -705,7 +705,7 @@ sea_main()
 loop:
 	done = 1;
 	for (unit = 0; unit < sea_cd.cd_ndevs; unit++) {
-		sea = sea_cd.cd_devs[unit];
+		sea = device_lookup(&sea_cd, unit);
 		if (!sea)
 			continue;
 		s = splbio();
diff --git a/sys/dev/isa/wt.c b/sys/dev/isa/wt.c
index 724323b56beb..068d9eb7b99f 100644
--- a/sys/dev/isa/wt.c
+++ b/sys/dev/isa/wt.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: wt.c,v 1.50 2000/06/26 14:59:04 mrg Exp $	*/
+/*	$NetBSD: wt.c,v 1.51 2000/07/06 02:02:50 thorpej Exp $	*/
 
 /*
  * Streamer tape driver.
@@ -325,11 +325,9 @@ wtopen(dev, flag, mode, p)
 	struct wt_softc *sc;
 	int error;
 
-	if (unit >= wt_cd.cd_ndevs)
-		return ENXIO;
-	sc = wt_cd.cd_devs[unit];
-	if (!sc)
-		return ENXIO;
+	sc = device_lookup(&wt_cd, unit);
+	if (sc == NULL)
+		return (ENXIO);
 
 	/* Check that device is not in use */
 	if (sc->flags & TPINUSE)
@@ -412,8 +410,7 @@ wtclose(dev, flags, mode, p)
 	int mode;
 	struct proc *p;
 {
-	int unit = minor(dev) & T_UNIT;
-	struct wt_softc *sc = wt_cd.cd_devs[unit];
+	struct wt_softc *sc = device_lookup(&wt_cd, minor(dev) & T_UNIT);
 
 	/* If rewind is pending, do nothing */
 	if (sc->flags & TPREW)
@@ -467,8 +464,7 @@ wtioctl(dev, cmd, addr, flag, p)
 	int flag;
 	struct proc *p;
 {
-	int unit = minor(dev) & T_UNIT;
-	struct wt_softc *sc = wt_cd.cd_devs[unit];
+	struct wt_softc *sc = device_lookup(&wt_cd, minor(dev) & T_UNIT);
 	int error, count, op;
 
 	switch (cmd) {
@@ -567,8 +563,7 @@ void
 wtstrategy(bp)
 	struct buf *bp;
 {
-	int unit = minor(bp->b_dev) & T_UNIT;
-	struct wt_softc *sc = wt_cd.cd_devs[unit];
+	struct wt_softc *sc = device_lookup(&wt_cd, minor(bp->b_dev) & T_UNIT);
 	int s;
 
 	bp->b_resid = bp->b_bcount;