Tale of the magnetic tape: 60 years at IBM

Tale of the magnetic tape: 60 years at IBM

Summary: In 1952 IBM solved the problem of using magnetic tape to back up computer-generated data.


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  • In 1952 IBM solved the problem of using magnetic tape to back up computer-generated data. The IBM 726 used a “vacuum column” that created a buffer of loose tape. This way, the relatively brittle tape could withstand the system’s fast starts and stops without snapping.

    The IBM 726 stored about 2.3MB of data and weighed 995 pounds.

    IBM claims that magnetic tape remains the most cost-effective, flexible and scalable medium for high-capacity storage backup today.

    Photo credit: IBM

  • In 1984 the IBM 3480 Magnentic Tape Subsystem which used a tape cartridge instead of the common reel-to-reel. It was smaller, faster and contained more storage capacity.

Topic: IBM

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  • Tape is alive and well and living outside the "cloud"

    I remember when a tape drive was show as a "Computer" in movies and TV shows.
    Still have a "write ring" or two at home.
    • tape

      No ringie no writie.
      • write ring (or not?)

        Univac I used rings to inhibit writing. No ring - write OK!

        Metal tapes.
    • Well

      Well, for that time computers did look better because they were huge tapes ;)
      Who would get exciting about real computers? :D

      Just like today people believe that GUI (any user interface) is the operating system while they don't even see the operating system in action.
  • Tape

    Still using the Reel 2 Reel tape, They seems to last forever, recorded in the 60's
    and still running. John
  • I remember it well

    used the write rings to play ring toss.
  • Tape as Intrmediate Storage

    On the IBM 709 (at the UofW in the early '60s) tapes were often used for intermediate storage for large data sorts. I think the main core memory was really small and there were no disks. And all the output went onto tapes including the printouts which were then processed on a 1401.
  • COBOL TOS Compiler

    All work files (SYSUTx) were on the tapes. I could tell which phase of the compiler was running by which tape drive was jiggling
  • Tapes

    Had a reason to look into those again for long term storge.
    Those are still expensive, I did not see any really large tapes/drives online.
    They used to be the thing to have.
  • ibm tapes

    For more history than you may want to know, check out the Emerson Pugh books -

    IBM's early computers

    IBM's 360 and early 370 computer systems

    MIT Press

    Note also that other companies had a read backwards capability earlier than IBM (actually it was there for the 701/702 tapes, but went away for the 704-705-709 vacuum tube machines, and the later pre-360 7090-7080-14xx-70xx machines with 727 and early 729 drives.

    In particular, Honeywell had vacuum capstan drives and superior sort performance in the late 1950's-early 60's.
  • saved my butt...

    when i was working as a newbie at the U of Chicago on a dictionary project. went in one night, called up a snippet from the dictionary to edit it, and wrote that snippet back to the dictionary--except i replaced the whole damn dictionary with the snippet. i discovered the error the next night. the night super said: "it's gone, finished, can't get it back". it scared me to death (almost). went in the next day and the kinder day supervisor told me to go to the university computer center and BUY a tape and have them restore the dict. from the previous week's university-wide backup. i lost a couple of days work. but: life saved, lesson learned, all homage to those taped backups!
  • Missing history?

    Interesting article, but missing a lot of detail from the heyday of tapes. Going from 556 bpi, to 800, 1600, then 6250. My favorite innovation (as an operator back in the day) was the self-loading jackets and drives. I remember splicing them when they broke and putting on the new silver reflector strip. Anybody ever clean a tape drive? Yep, they sure left out the middle of tape history.