If you are SCSI familiar then the PCI SCSI card idea may work easiest, get like an Adaptec 2940 or equal. If set to 10Mb for that device ID should be OK. Or set up the Pentium box with original controller.
One quirk could be if the data was compressed or encrypted then you would need an app (or the original Tape app) in order to extract.
If just files written to tape then once you get the SCSI card and Tape drive recognized should be able to just copy the files to an HD.....

Modern Linux should still support something like a dirt common AHA-2940 card (AIC-78xx). DDS3 is pretty new as far as DAT drives are concerned. If you have a machine with PCI slots, throw it in and try a modern Linux distro. Hopefully your tapes are direct TAR, makes restoration easy.

NJRoadfan wrote on 2021-09-04, 01:16:

Modern Linux should still support something like a dirt common AHA-2940 card (AIC-78xx). DDS3 is pretty new as far as DAT drives are concerned. If you have a machine with PCI slots, throw it in and try a modern Linux distro. Hopefully your tapes are direct TAR, makes restoration easy.

Yeah that's the option I was considering. I'm pretty sure I just tar'd the files directly onto the tape...

Mauybe it's easiest and safest to use a contemporary linux box, hook up the drive and then dump the tape contents into raw files, which you can process later.
Because, it is well possible that the tapes will last only one playback, if at all.
It might be a good idea to prepare also for drive cleaning, as long ago when I tried to read back old QIC tapes, the magnetic coating already was quite loose 😢 and the attempt to recover the data was abig fail.

You'll be extremely lucky if the tape drive actually works. We run the Compaq DDS3 drives at work in our Alpha Servers and all of them have failed.. and all of the replacement drives have failed.

I wouldn't be too worried about the DDS3 tapes themselves. They are pretty reliable and I've pulled 15 year old tapes out of the cabinet and never had issues with them. The hardest part is getting the drive to work right.

At least some DDS-4 and newer drives are compatible with DDS-3 media . AFAIU, this needs to be checked on a per model basis as it is not a given for all newer drives . Here is an example compatibility matrix for HP drives :

https://www.artisantg.com/info/HP_DAT_Compata … ility_Chart.pdf

It's successfully formatted a spare tape, so I assume the drive is OK.

I can't quite figure out how to get a raw tape dump; dd if=/dev/st0 of=somefile just dumps 32kb.

What it dumps LOOKS like good data from the tape (pre-erase):
00000000: 4845 4144 4552 5149 4331 3133 0700 0100 HEADERQIC113....
00000010: 0000 0000 0000 0042 6163 6b75 7020 4d65 .......Backup Me
00000020: 6469 6120 3030 3030 3120 2020 2020 2020 dia 00001
00000030: 2020 2020 2020 2020 2020 2020 2020 2020
00000040: 2020 2026 061e 3f41 7263 6164 6120 536f &..?Arcada So
00000050: 6674 7761 7265 2c20 496e 632e 2020 2020 ftware, Inc.

null

Yeah I was just looking at the devices. I'm using Debian.

nst0
nst0a
nst0l
nst0m
st0
st0a
st0l
st0m

I'll see if google can help me out there with the a/l/m designations, but st0 is rewinding device and st0m is non-rewinding device, that's all I know right now.

I think the 32kb is just the first file, there's multiple files on the tape I guess.

null

Interestingly this drive doesn't seem to want to accept DDS3 cartridges; DDS2 work fine.

I'm POSITIVE I used this drive to make the backups I'm trying to recover, so this is very strange to me.

It's an HP C1539 which a web search reports is in fact a DDS2 drive...

Just found a sealed new-in-box DDS4 tape drive on Ebay for $60, that ought to be able to read these tapes. I'll check back in next week after it arrives I suppose.

keenerb wrote on 2021-09-11, 01:06:

Just found a sealed new-in-box DDS4 tape drive on Ebay for $60, that ought to be able to read these tapes. I'll check back in next week after it arrives I suppose.

Make sure the specific DDS-4 model is DDS-3 compatible, not all DDS-4 drives are .

Documentation I found specifically mentions dds3 support.

Is it possible the dds3 drives were detected and written as dds2 in my existing unit? I have only ever had a single tape drive and a small number of tapes...

I've written DDS2 tapes using a plain old DDS drive and it worked fine. The header your dump shows is not TAR though, it was likely created with Arcada/Seagate/Whoever owns them today Backup Exec on Windows.

Yeah that was a test tape, not one i created. My tapes are labelled TAR format so i am optimistic they are simple tar archives.

DDS4 tape drive seems to be what I needed.

First tape I checked is apparantly windows backup:
Windows NTbackup archive NT, with file catalog, soft size 0*512, name: PICTURE ARCHIVE 08/08/08MTF Media Label|1.0|Seagate|NTBackup5.0|2008/08/08.02:00:24|Seagate 2008/08/08.02:00:24|1|{BF163C5F-3C4, label: MTF Media Label|1.0|Seagate|NTBackup5.0|2008/08/08.02:00:24|Seagate 2008/08/08.02:00:24|1|{BF163C5F-3C4F-4347-B972-50E1B1DEC8F4, software (0xcbe): Backup Utility (NTBACKUP.EXE) Version 1.0 Rev. 3.41SA

Second tape looks to be tar, I'm dumping it with DD right now. Hoping for the best!

Everything was recovered. Earliest tape was simply a tar archive, second tape I recovered by dd on all the tape files, concatting them together, and converting to a tar with mtftar.

I also now have about twenty new dds3 tapes and a brand new dds4 drive setup in one of my linux servers, might as well put those to use, maybe in another fifteen years I can make another post asking how to recover THOSE tapes...