Forensic analysis for 50 year-old tape?

I think you should reach out to Jason Scott over at the Internet Archive. He's been involved with helping people get old stuff off of old media before and if he doesn't have the tech and know how, chances are high he knows who to ask.

He's very easy to reach on Twitter, @textfiles.

This probably isn't going to help the poster specifically but it's an excuse to share a good presentation from Vintage Computer Fest West 2020 re: magnetic tape restoration: https://www.youtube.com/watch?v=sKvwjYwvN2U

I believe the presenter's tape was also from an IBM 360. I guess maybe, if the rig the presenter used to read his tape still exists, this might be of use to the poster. The presenter had a tape from his college days in the 1960s, stored in less than ideal environmental conditions, that he wanted to read.

The presentation explores using software to digitize and analyze the analog signal generated by the flux transitions on the tape to reconstruct the data. Essentially, it's moving the digital portion of the tape drive into a software domain and doing signal processing. Software-defined radio kind of stuff, to some extent. Very similar to the efforts to preserve floppy disks (which are kinda like tape drives for tiny circular tapes, basically) by recording the flux transitions and processing them.

The presentation gets into some work applying these techniques to reconstruct tapes recovered from the Whirlwind project, too.

>50 yr old tape< = circa:1972 vintage Tape

search: >'magnetic tape restoration'< @DDG : <https://html.duckduckgo.com/html/?q='magnetic tape restorati...>

The chances of reading the data will depend on several factors;

  1. The tape-stock (base and binder stability), the stored temperature, humidity and magnetic field exposure.

  2. A working and aligned reader.

Background.

The IBM System/360 (S/360) : https://en.m.wikipedia.org/wiki/IBM_System/360

Is a family of mainframe computer systems that was announced by IBM on April 7 1964, and delivered between 1965 & 1978.

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Extended Binary Coded Decimal Interchange Code (EBCDIC ) : https://en.m.wikipedia.org/wiki/EBCDIC

Is an eight-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems.

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Also See;

search: >'NASA call for Moon tapes'< @DDG : <https://html.duckduckgo.com/html/?q='NASA call for Moon tape...>

The geophysical industry used 9-tracks for a long time and there are still services that will recover your legacy tapes and reformat to any modern output.

I have never used these guys, OnTrack(0), but they claim to do 9-track recovery.

Everything we did in the industry for decades lived on 9-track tapes. EBCDIC headers are a standard feature of SEG-Y output datasets.

Here is one who deals with geophysical data, Data Strategies Interchange(1).

[0] (https://www.ontrack.com/en-us/tape-services)

[1] (https://go-dsi.com/seismic-data-transcription/)

Good luck. Sounds like a fun project. I wrote a SEGD/SEGY reader for geophysical data a long time ago using tcl/tk. It was surprisingly easy. It used data from disk files though. I got rid of my SCSI 8mm and DLT drives a long time ago and went to pure disk IO. No more issues spinning tapes after that. In the industry though we did have some really good tape reading/writing/checking routines. Haven't done that since the mid-90's myself.

Email George Blood LP (https://www.georgeblood.com/), they have support to read like 100+ old magnetic formats and are wonderful pros.

Aside from the physical encoding, note the conventions for IBM tape file sequence and labeling:

https://www.ibm.com/docs/en/zvse/6.2?topic=SSB27H_6.2.0/fa2m...

You can bypass default label assumptions and label processing using JCL directives like BLP, NL, etc.

When I was in mainframe operations and at times ran the Production Control Center (triage), I rescued some systems from being rerun due to clobbered labels by altering JCL.

Contact this guy: https://www.youtube.com/c/CuriousMarc

If he does not have a machine capable of reading the tapes in his house/museeum, he will know someone who has.

(and as a bonus, the recovery might end up as a entertaining youtube video)

There is a pretty marvelous woman, named Marianne Bellotti. She probably couldn't help you directly, but she's a total "old computer" nerd.

https://www.marianne-bellotti.com

I do not have contact info for her, and she has no idea who I am, so you're on your own...

I'm guessing that would be one of the old reel to reel tapes. I think the hardest part (assuming the tape is intact) would be finding a working tape reader. From pictures I've seen I think those were real beasts, in cabinets as large as the mainframe itself. The Computer History Museum in Mountain View CA is one of the few places that might have one.

Otherwise you might be able to build your own tape reader. You could probably make it a lot smaller and simpler than the original machines since throughput wouldn't really be an issue. Still it would probably be quite an engineering project.

1) be careful! The magnetic coating will flake off and you will lose the data. Research a bit: this is a solved problem. There are chemical treatments to render the oxide coating more flexible for an attempt at reading it.

2) is there a way to avoid forcing physical contact with rubber capstans as you attempt to pass it over a magnetic play head? Is there an alternative magnetic sensing technology you can use to extract the data vs a proximity based typical tape playback head?

I'm curious if there is something valuable on this or if you are just doing this for the challenge.

Get yourself a TEAC/Tascam 8 track reel-to-reel and digitize the tracks, then take it from there on a DAW.

IBM’s dusty tape lab used to be in Tucson. Recovered the space shuttle tapes iirc.

OP here. These are some really great ideas here and I thank you.