diff --git a/sys/scsi/scsiconf.c b/sys/scsi/scsiconf.c
index 44be2bc38d81..fdc0efb0facb 100644
--- a/sys/scsi/scsiconf.c
+++ b/sys/scsi/scsiconf.c
@@ -16,7 +16,7 @@
  *
  * New configuration setup: dufault@hda.com
  *
- *      $Id: scsiconf.c,v 1.50 1996/02/02 22:57:27 joerg Exp $
+ *      $Id: scsiconf.c,v 1.51 1996/02/02 22:59:47 joerg Exp $
  */
 
 #include <sys/types.h>
@@ -191,6 +191,13 @@ static st_modes mode_tandberg3600 =
 	    {0, 0, QIC_150},				/* minor 8,9,10,11 */
 	    {0, 0, QIC_120}				/* minor 12,13,14,15 */
 	};
+static st_modes mode_tandberg4200 =
+	{
+	    {0, 0, 0},					/* minor 0,1,2,3 */
+	    {0, ST_Q_FORCE_VAR_MODE, 0},		/* minor 4,5,6,7 */
+	    {0, 0, QIC_150},				/* minor 8,9,10,11 */
+	    {0, 0, QIC_120}				/* minor 12,13,14,15 */
+	};
 static st_modes mode_archive2525 =
 	{
 	    {0, ST_Q_SNS_HLP, 0},			/* minor 0,1,2,3 */
@@ -259,6 +266,10 @@ static struct scsidevs knowndevs[] =
 		T_SEQUENTIAL, T_SEQUENTIAL, T_REMOV, "TANDBERG", " TDC 3600", "*",
 		"st", SC_ONE_LU, ST_Q_NEEDS_PAGE_0, mode_tandberg3600
 	},
+	{
+		T_SEQUENTIAL, T_SEQUENTIAL, T_REMOV, "TANDBERG", " TDC 42*", "*",
+		"st", SC_ONE_LU, ST_Q_SNS_HLP|ST_Q_NO_1024, mode_tandberg4200
+	},
 	{
 		T_SEQUENTIAL, T_SEQUENTIAL, T_REMOV, "ARCHIVE", "VIPER 2525*", "-005",
 		"st", SC_ONE_LU, 0, mode_archive2525
diff --git a/sys/scsi/scsiconf.h b/sys/scsi/scsiconf.h
index a717ccc1bdb8..a21450f0922a 100644
--- a/sys/scsi/scsiconf.h
+++ b/sys/scsi/scsiconf.h
@@ -14,7 +14,7 @@
  *
  * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
  *
- *	$Id: scsiconf.h,v 1.37 1996/01/07 19:27:06 gibbs Exp $
+ *	$Id: scsiconf.h,v 1.38 1996/01/20 15:05:53 joerg Exp $
  */
 #ifndef	SCSI_SCSICONF_H
 #define SCSI_SCSICONF_H 1
@@ -257,6 +257,7 @@ typedef struct st_mode st_modes[4];
 #define ST_Q_IGNORE_LOADS	0x0010
 #define ST_Q_BLKSIZ		0x0020	/* variable-block media_blksiz > 0 */
 #define ST_Q_CC_NOMSG		0x0040	/* no messages accepted in CC state */
+#define ST_Q_NO_1024		0x0080	/* never ever use 1024-byte fix blk */
 
 #define ST_Q_NO_SYNC		SCSI_Q_NO_SYNC
 #define ST_Q_NO_FAST		SCSI_Q_NO_FAST
diff --git a/sys/scsi/st.c b/sys/scsi/st.c
index 2c204cfdbe2b..ac616d768429 100644
--- a/sys/scsi/st.c
+++ b/sys/scsi/st.c
@@ -12,7 +12,7 @@
  * on the understanding that TFS is not responsible for the correct
  * functioning of this software in any circumstances.
  *
- * $Id: st.c,v 1.58 1996/01/14 16:29:01 joerg Exp $
+ * $Id: st.c,v 1.59 1996/01/29 03:19:23 gibbs Exp $
  */
 
 /*
@@ -757,6 +757,9 @@ st_decide_mode(unit, first_read)
 	case HALFINCH_1600:
 	case HALFINCH_6250:
 	case DDS:
+	case QIC_525:
+	case QIC_1320:
+	case QIC_3080:
 		st->flags &= ~ST_FIXEDBLOCKS;
 		st->blksiz = 0;
 		SC_DEBUG(sc_link, SDEV_DB3, ("density specified variable\n"));
@@ -765,9 +768,6 @@ st_decide_mode(unit, first_read)
 	case QIC_24:
 	case QIC_120:
 	case QIC_150:
-	case QIC_525:
-	case QIC_1320:
-	case QIC_3080:
 		st->flags |= ST_FIXEDBLOCKS;
 		if (st->media_blksiz > 0) {
 			st->blksiz = st->media_blksiz;
@@ -1993,7 +1993,7 @@ st_touch_tape(unit)
 	if (( errno = st_mode_sense(unit, 0, NULL, 0, 0)) ) {
 		goto bad;
 	}
-	st->blksiz = 1024;
+	st->blksiz = (st->quirks & ST_Q_NO_1024)? 512: 1024;
 	do {
 		switch ((int)st->blksiz) {
 		case 512: