SUMMARY: DDS-2 Tape Drives on SPARCstation-5 with SunOS 5.5

From: Srinivas Maddhi (
Date: Mon Feb 16 1998 - 20:17:58 CST

First off, sorry for the delay in replying.

Original edited query:

On 29 Jan 1998 21:46:42 -0600 Srinivas Maddhi <>

> I need help determining if it is feasible to go from an existing
> Python 4mm DDS-1 tape drive to a DDS-2 tape drive on the hardware and
> OS combination: SunOS foo 5.5 Generic sun4m sparc SUNW,SPARCstation-5.
> These are the questions to which I am looking for answers:
> 1. Are either of these drives known to be compatible with the hardware
> and OS in question
> 2. An outline of what is involved in configuring these.
> 2. Is the OS, hardware able to take advantage of the hardware
> compression on these drives.
> 3. Can the OS, hardware sustain the transfer rates claimed by these
> drives.

Thanks to the two responders, Dan Pritts and Karl Vogel:

On Fri, 30 Jan 1998 11:48:20 -0500 (EST) Dan Pritts <>

> i've used dds-2 drives with few problems. You just need to get it
> from a place that supports using it with solaris (or be willing to
> extract the instructions from HP), and be willing to edit your
> /kernel/drv/st.conf file as appropriate.

On Fri, 30 Jan 1998 11:50:55 -0500 (EST) Karl Vogel
<> wrote:

> We're moving in that direction. We bought a StoragePack from Sun,
> and had no problems installing or testing it. All I'm waiting for
> are the tapes.

My experiences:

We chose the HP C1599A mechanism. It came with documentation and a
loose sheet of paper with the recommended DIP switch configuration for
PC, Sun, IBM and DEC.

"UNIX Configuration Guide, Sun Workstations" at has all the info one needs to set up
this drive.

In additions archives of this mailing list and comp.sys.sun.* proved
very helpful.

My final configuration:

foo.18[~]% cat /kernel/drv/st.conf | egrep -v '^#|^$'
tape-driver-buffering = 4;
tape-config-list =
        "HP C1533A", "HP DDS2 4mm DAT", "HP-DAT";
HP-DAT = 1, 0x34, 0, 0xd639, 4, 0x00, 0x13, 0x24, 0x3, 3;
name="st" class="scsi"
        target=0 lun=0;
name="st" class="scsi"
        target=1 lun=0;
name="st" class="scsi"
        target=2 lun=0;
name="st" class="scsi"
        target=3 lun=0;
name="st" class="scsi"
        target=4 lun=0;
name="st" class="scsi"
        target=5 lun=0;
name="st" class="scsi"
        target=6 lun=0;

DIP Switch setting: 1111 1001
Alternate DIP Switch setting: 1110 1100

I was able to get approximately 1100 KB/s of throughput with the either
of the two DIP switch settings mentioned above when the drive was
connected to the second SCSI bus on an SS5 as the sole device on that

Connecting it to an SS5 with only one SCSI bus and having four other
devices attached to that bus drops the transfer rate to ~ 700 KB/s.

Notes/ Unresolved issues:

1. 'mt erase' causes the drive to keep trying to erase the tape for ever.
    Any 'mt' commands issued subsequent to an 'mt erase' fail and cannot
    be stopped unless the tape is forcibly ejected.
2. 'probe-scsi' reports the drive as a HP C1533A instead of an HP C1599A

Srinivas Maddhi
CCAD Computing Services

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