Author Topic: Digitizing NASA data tapes  (Read 152 times)

Offline apollo16uvc

  • Earth
  • ***
  • Posts: 113
  • Where no telescope has gone before.
    • Apollo 16 UVC
Digitizing NASA data tapes
« on: February 12, 2018, 03:20:59 PM »
I am in contact with someone who will help me read NASA data tapes from the 60s to 70s

Some quick looks at the tapes showed Lunar Orbiter, Apollo, Skylab and sattelite 1/2 inch computer tapes.

They Will be uploaded to archive.org as public domain.

I will post findings and relevant parts of our conversation here.

Some tapes cost 80 dollar to acquire, if you want to help finance this you can email apollo16uvc@gmail.com

Regards,
Apollo16uvc
« Last Edit: February 12, 2018, 03:25:43 PM by apollo16uvc »
Ultraviolet light photography rules!
Apollo 16
Skylab

Offline apollo16uvc

  • Earth
  • ***
  • Posts: 113
  • Where no telescope has gone before.
    • Apollo 16 UVC
Re: Digitizing NASA data tapes
« Reply #1 on: February 12, 2018, 03:21:23 PM »
Me: "
Today I played part of the tape through an AKAI X201D. I did not expect to get any usable data, maybe a faint signal.

You can find WAV files and spectrograms here: https://drive.google.com/drive/folders/17vss0VXnpmGchf0DuRh3w2wXxNNphkYA?usp=sharing

Test001.wav through Test003.wav were manually moved along the heads. test004.wav and test006.wav was fed along the heads via the capstan at 3 3/4. test005.wav is played at 7 1/2 inches per second.

Test005.wav has a continuous tone.
test006.wav is the very beginning of the tape, and has weird bursts at the beginning."

Contact: "Having done a number of these for JPL, I'd say that this is a 7-track 800 BPI NRZI tape. Depending on the exact tape drive, it can probably be read on a 729-equipped 1401. Making sense of the data, however, is another story. Early 1960s NASA tapes tended to be 7090/94 ones, with later ones, Univac 1100 series right up through the early 1980s.

Or you can send it to me and I'll extract the data. My contacts at JPL say there are thousands of these things kicking around."

Me: "Thank you very much for your reply.

Can you any sense out of the sound recordings I have made? what are the short bursts on test006 and the tone on test005.


I would be incredible thankful if you could extract the data. How to best ship a tape? I have to send mine from the netherlands to your place, which I assume is America. Any further tapes I get I might have shipped directly to you from a seller in America. Whatever you want.

I know a lot of people will be excited to look at the recovered data.

Is it possible you can try and get the tape identified by the people at JPL? I did scrub off the upper label to reveal the lower label with some more information.."

Contact:"
No, I do not think that I could do anything with your audio. Perhaps an examination with a magnetic developer (such as Kyread) and a low power microscope would verify my suppositions. That would at least tell you how many tracks are involved and define the inter-block spacing, if applicable.

There's a faint possibility that these might also be analog telemetry tapes, but a view with a magnetic developer would verify that. However, what I can see of the partially-covered label seems to indicate a standard digital tape, but the note on the label that says "audio" is puzzling. Were that the case, you should be able to get something using an audio recorder to play these back.

I was under the impression that tapes used for analog telemetry back in the 60s was very different from standard 10.5" 1/2" tape, but you never know.

They're definitely digital tapes if you have blocks of data separated by approximately 3/4" of erased space. That's standard 7 track format.

Finally, a lot of these tapes are simple recertified "scratch tapes"--that is, used tapes returned to the scratch pool and run through a certifier (which erases all data). A tape label that specifies contents and the name of the programmer holds out the best hope, but even so, in the lots I've handled, about 10% were recertified scratch. NASA, like a lot of government operations, re-used tapes heavily, trimming off tape at the beginning when it wore out and applying a new BOT marker. Some of the tapes that I've worked on have several hundred feed sacrificed.

A lot of this stuff is mixed-format data (some text, a lot of binary) data that may be very difficult to suss out without the program that created it. For example, here's one of the tapes that I did: Mostly 7094 floating-point data with a few bits of 7090 BCDIC mixed in."

Me:"Really cool that you worked on NASA tapes before, how did that come to be? and how do the tapes usually end up in the 'wild'?

There are many unknowns, but with small steps I believe we can figure this out.

I looked around for Kyread, and buying from their website the shipping cost alone is 150 dollars. I can buy magnetic viewing film much cheaper, do you think it has enough resolution to view the tracks?

If it does have analog telemetry, is there a special type of audio recorder we need to play them on? or will any 7 track multi track recorder do? I do not know if a 1/2 inch 7 track audio recorder exist, 1/2 inch 8 track tape recorders were more common. Today I spooled the tape through my 1/4 inch 4 track stereo recorder again, this time there were 4 to 5 distinct frequency tones in the spectogram instead of one. Could it be overlapping tracks?

Is it possible rectifying a tape causes this continuous tone?

I may get some NASA tapes soon that have a greater potential to hold data."
*Pictures of tapes for sale*

Contact:"My tapes came directly from NASA JPL in Pasadena. I do not own them--and they were returned after data retrieval, along with the data retrieved from them. In other words, it's JPL's property, not mine and I treat it that way.

Kyread is nothing more than 1 to 3 micron iron particles in a fast-evaporating fluid (it used to be a type of Freon, but since that was banned, methyl perfluoroisobutyl ether is used). It is relatively inert, so it does not affect the coating or base material. You shake the bottle up and drop a drop of the suspension on the tape and allow the solution to evaporate. Since the iron particles are so small, you can visualize very small features in the tape. With a decent chemistry lab, it should not be difficult to mix some of this up in your location, assuming that the carrier liquid is legal in the EU.

When I have a new tape, unless I'm very certain about the content, this is always the first step. Tapes labeled as 9 track often turn out to be 7 track and vice-versa. What are you going to believe, your eyes or some lying label?

The other thing is preparation of the medium. Normally, the procedure is to "bake" the tape, then run it through a tape cleaning machine. Additional treatment may be necessary, such as lubrication, to get the tape to read. After all, you have no idea of the storage conditions during the 50 or so years that the tape has been in storage. It's not uncommon for splicing tape (used to attach leaders) to dry out and let go, so you have to be prepared for that. BOT and EOT markers similarly dry out and fall off...

The tapes you pictured above are certainly data tapes and definitely 7-track (9 track tapes don't usually occur with even parity). But you can't get your expectations too high. The Apollo program involved hundreds of subcontractors who generated probably tens of thousands of tapes. The GE tapes you show above may be nothing more than engine test data--and like such things, you need a Rosetta stone to interpret it, since it's unlikely that the data will contain any clues. Before the days of high-speed telecom and big disk drives, tape was king. Outfits like NASA ordered tapes by the truckload.

But, if you're willing to take a shot, I'm willing to have a go at it. I'll PM you my shipping address."

Our conversation continued in private and got quite technical.

I will try to get the tracks visualized on the tape currently with me and am looking into getting it played on a multitrack 1/2 recorder, if it is analog telemetry we might get something.

As for the data tapes, my contact will handle those.

Regards,
Apollo16uvc
Ultraviolet light photography rules!
Apollo 16
Skylab

Offline apollo16uvc

  • Earth
  • ***
  • Posts: 113
  • Where no telescope has gone before.
    • Apollo 16 UVC
Re: Digitizing NASA data tapes
« Reply #2 on: February 12, 2018, 03:22:23 PM »
"You can see an HP 7970 tape drive demonstrated at about 7:11 in this video:

https://www.youtube.com/watch?v=eCBxNhEzIfc

Mine is a 7970B, modified to use a 7-track head instead of the standard 9 track one. The interface is "raw", which feeds into an STM32F407 microcontroller, which writes to a micro SD drive. While I could probably write 7 track tapes, mine is configured as read-only.

For 9 track tapes, I have several drives, but the one that I used most is a Fujitsu M2444 drive. It's impossible to see it working, as the door must be closed for it to operate. That is fed by a 16-bit ISA controller in a PC. The whole affair is rack-mounted."

The first tape has been send: https://www.ebay.com/itm/332544367534?ViewItem=&item=332544367534

As for the "Audio tape" I will be getting someone locally to play it with a multi track audio recorder. It is this tape: https://www.ebay.com/itm/Vintage-NASA-Audio-Data-Tape-Reel-From-The-1960-039-s-Who-Knows-What-May-Be-On-This-/332455504748
« Last Edit: February 12, 2018, 03:24:45 PM by apollo16uvc »
Ultraviolet light photography rules!
Apollo 16
Skylab

Offline apollo16uvc

  • Earth
  • ***
  • Posts: 113
  • Where no telescope has gone before.
    • Apollo 16 UVC
Re: Digitizing NASA data tapes
« Reply #3 on: February 17, 2018, 02:40:00 PM »
Tape: NASA Automatic Data Processing 4141 has arrived.

Update written by contact:

"Niels,
 
 The tape arrived today--the photos don't do it justice(?).    The reel is chipped and absolutely filthy--it looks as if it spent the past 50 years on the floor of someone's garden shed.
 
 At this point, it's difficult to tell how much of the tape is intact.   This is my plan:
 
 1.  Bake the tape for a day or two
 2.  Run it through the cleaning machine a couple of times to remove as much of the dirt as possible
 3.  Clean the reel and re-spool the tape
 4.  Try to see if there's anything readable
 
 How does this sound?"

"Well, I unreeled a bit of the tape; I didn't find a BOT marker, so I suspected that the first few meters of the tape are history
 
 Here's what I see when I look at the tape:
 
 9-track, not 7!  If the date on the tape is correct, this means it was produced on an IBM System/360, as almost nobody else had working 9 track drives then.    Even in 1965, IBM was shipping the first S/360s out with 729 7-track drives.   It took them awhile to get the bugs out of the 2400 series drives.
 
 Testing the very beginning of this very wrinkled tape shows data on the first few cm, so if there was a leader, it's been long gone.
 
 I'll bake and clean the tape and attach a BOT marker about 3 m in and see what I can see with my 9-track drives.  This may take a few days."
Ultraviolet light photography rules!
Apollo 16
Skylab

Offline apollo16uvc

  • Earth
  • ***
  • Posts: 113
  • Where no telescope has gone before.
    • Apollo 16 UVC
Re: Digitizing NASA data tapes
« Reply #4 on: February 18, 2018, 07:36:10 AM »
The tracks on the tape visualized with a magnetic viewing solution:

Ultraviolet light photography rules!
Apollo 16
Skylab