DDS/DAT notes

These are some general notes on DAT and DDS drives.

I fell into this rabbit-hole after someone gave me a HP DAT72 drive, and I picked up a Tascam DAT deck and a couple of Archive DAT-capable drives. DAT has since become my go-to for data interchange between older and newer systems, especially under UNIX or where I have a SCSI card available in the origin machine. (generally I use LTO for more modern platforms).

My usual route is to fit a DDS-3 or DDS-4 drive in the source system, and use a HP Storageworks USB DAT72 to read the tape on a newer PC.

For recovering data from old tapes, I use a mix of the drives below:

  • DAT-Audio, DDS-1: Archive 4320 (DAT-Audio firmware) or or 4326 (DAT-Audio firmware).
  • DAT-Audio, DDS-2: Archive 4326 (DAT-Audio firmware).
  • DDS-3, DDS-4/DAT40 and DAT72: HP Storageworks DAT72 USB

I've yet to acquire a DAT80 or DAT160 drive or media. I suspect that most DAT users didn't go much beyond DAT72, and specified LTO when they upgraded. AIT and DLT were also available at the time, but the majority of used tapes I've seen on the market have been DAT or LTO.

This table only includes the drives I have personally used, and the variants I know of. Where a variant I have not personally used is listed, DAT Audio support is listed as “:?:” (unknown).

Make and model DAT Audio DDS-1
60m (1.3/2.6GB)
90m (2/4GB)
120m (4/8GB)
125m (12/24GB)
150m (20/40GB)
DDS-5 / DAT-72
170m (36/72GB)
Archive 4320NT (25601) v2.xx EPROM swap Firmware >2.19 needed for 90min/2GB tapes. Firmware >2.96 needed for reliable use of MRS tapes. See this page.
Conner CTD2004-S :?:
Seagate STD12000N :?:
Archive 4326NP (01931) Flash See
Good drive for DAT-audio.
Conner CTD8000R-S :?: Post Seagate buyout of Archive
IBM 59H2683, 59H2681 :?: IBM version with black tape door, blue eject button and IBM-styled front.
HP SureStore DAT 4/8 No Not recommended: Used drives tend to be dead (even new-old-stock ones), with servo and Drum PG failures.
Seagate STD24000N (04106) No Good narrow-SCSI drive, with DDS-3 tapes pairs well with HP DAT72 USB for easy exchange with newer machines.
Media compatibility - see
Seagate STD2401LW (06408) No Good all-round DDS-4 Wide SCSI drive with good format compability. 68-pin interface with Narrow/Wide jumper, should work with 50-to-68-pin adapters. AKA “Scorpion 40”.
Sony SDT-10000 No Good all-round DDS-4 Wide SCSI drive with good format compability. 68-pin interface. Narrow/Wide support unknown.
HP StorageWorks DAT72 USB No Decent later-DDS drive. Good for reading and writing later (DDS3+) tapes.
HP StorageWorks DAT72 SCSI No Needs a terminating SCSI adapter when used on narrow SCSI buses, no Wide/Narrow jumper.


  • ✅: Read and write
  • 👓: Read only
  • ❌: No support
  • General notes:
    • 60-metre (1.3GB) DDS-1 is rarely seen. 90-metre is more common.
    • DDS-2 drives will usually read and write 60- and 90-metre DDS-1
    • DDS-3 drives will usually read and write 60- and 90-metre DDS-1 and 120-metre DDS-2
    • DDS-4 drives will usually read and write 120-metre DDS-2 and 125-metre DDS-3, and sometimes 90-metre DDS-1 (Seagate STD2401, STD6401, per this Seagate page)
  • Archive 4320 and variants:
    • DDS-1 uncompressed only, no DDS-DC data compression support.
    • There are two variants of this drive. V2.xx Firmware is ROM-based, on Python hardware. v5.xx is Peregrine-based.
  • DAT Audio – see:
  • If the drive powers up and passes selftest, but won't read or write, try feeding it a DDS cleaning cartridge four or five times.

This section has an extremely long list of names, because of the chain of ownership of this company.

What started out as Archive (or possibly Ardat), was bought by Conner, then bought by Seagate, spun off as Certance, and finally bought by Quantum.

Quantum DLT and LTO drives seem to be from a different pedigree.

From: Seagate DAT installation manual, Interpreting Seagate tape model numbers

Archive Conner Seagate Format/capacity Form factor
4320NT CTD2004H-S STD12000N DDS-1 3.5in internal (CD-ROM height, narrow face; fills 2x 3.5in bays or 1x 5.25in with rail kit)
4320RT CTD2004R-S STD22000N 5.25in internal (CD-ROM size, wide face; fills 1x 5.25in bay)
4350XT CTD2004E-S STD62000N External
4324NP CTD4004H-S STD14000N DDS-DC 3.5in internal (CD-ROM height, narrow face; fills 2x 3.5in bays or 1x 5.25in with rail kit)
4324RP CTD4004R-S STD24000N 5.25in internal (CD-ROM size, wide face; fills 1x 5.25in bay)
4324XP CTD4004E-S STD64000N External
4326NP CTD8000H-S STD18000N DDS-2 3.5in internal (CD-ROM height, narrow face; fills 2x 3.5in bays or 1x 5.25in with rail kit)
4326RP CTD8000R-S STD28000N 5.25in internal (CD-ROM size, wide face; fills 1x 5.25in bay)
4326XP CTD8000E-S STD68000N External

Which decodes as …

Archive base model code Form factor code Suffix code
4320: DDS-1 (Python/Peregrine) N: Narrow “3.5in” T: DDS-1 drives
4324: DDS-DC (Peregrine) R: Wide “5.25in” P: DDS-DC, DDS-2
4326: DDS-2 (Peregrine) X: External
4350: DDS-1 External

4320 exists in two variants: firmware v2.xx is Python (OTP ROM), v5.xx is Peregrine (Flash/EEPROM).

Conner Tape prefix Capacity/format/model Form factor
CTD 2004: DDS-1 H-S: narrow “3.5in”
4004: DDS-DC R-S: wide “5.25in”
8000: DDS-2 E-S: external
Seagate prefix Form factor Capacity/format/model Suffix
STD 1: narrow “3.5in” HH 2000: DDS-1 N
2: wide “5.25in” HH 4000: DDS-DC
6: external 8000: DDS-2
24000: DDS-3 (Scorpion 24)

The STD-series drives are from the Scorpion family (see this page) and have a native transfer rate of 550Kbytes/sec, vs. the 400Kbytes/sec of the previous drives.

The STD224000N has a native transfer rate of 1.1Mbytes/sec.

STD2401LW is DDS-4, 20GB native (40GB compressed). Certance sold this drive as the CD40. Transfer rate is quoted at 9.9GB/hour, which is around 2.75 megabytes per second. The Quantum firmware update isn't archived, but the Dell version is:

Generally speaking, the Internet Archive Wayback Machine:

Some manuals are stored on Bitsavers:

I've found these drives to be extremely unreliable – both drives I have (one was new in box) were dead with “servo hung” and “drum PG lost” errors. I haven't been able to fix these drives, it seems to be a tape transport issue.

They are “okayish” as a source of parts – there are some fast amplifiers, a 68EC000 processor, and RAMs and ROMs on the mainboard.

HPE have removed most of the software for their earlier drives from their website. The last remaining holdouts are:

  • Library and Tape Tools version 4.28sr2:
    curl -fL -o "hpe_ltt428_hpux_1123.tar"
    curl -fL -o "hpe_ltt428_hpux_1131.tar"
    curl -fL -o "hpe_ltt428_linux_x86.tar"
    curl -fL -o "hpe_ltt428_linux_x86_64.tar"
    curl -fL -o "hpe_ltt428_mac.dmg"
    curl -fL -o "hpe_ltt428_solaris_amd64.tar"
    curl -fL -o "hpe_ltt428_solaris_sparc.tar"
    curl -fL -o "hpe_ltt428_win.exe"
    curl -fL -o "HP-I64VMS-LTT-V0428--1.ZIPEXE"

The files below are for the SDT-10000 and are untested.

The diagnostic tool for Sony DAT/DDS drives is TapeTool.

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  • Last modified: 2024/04/05 14:26
  • by philpem