Magnetic tape has been used as a storage medium continuously from one of the first contemporary computers onwards – the UNIVAC, in 1951. That gives it 60 years of unbroken use, from gigantic reel-to-reel rolls of the stuff to tape cartridges that might one day hold 70 terabytes apiece.
And who needs tape? Anyone who has to store unbelievably huge quantities of data, for one. Here’s a robotic tape-backup system running at the National Center for Atmospheric Research, which deploys a fleet of supercomputers against the world’s most computationally-intensive climate modeling problems.
Tape is not only the longest-running digital storage medium still in use, it’s the longest-running one ever. To be fair, this title is limited by the length of time we’ve had digital computers. Charles Babbage proposed using paper tape on his Difference Engine, an idea he borrowed from looms. And then there’s the question of whether or not Herman Hollerith’s introduction of punched cards for the 1890 census counts as a digital storage medium – I say no, since the machines that used it were adding machines, not proper Turing machines.
Punch cards may have been among the first storage mediums for computers, but they didn’t last long, and were supplanted by everything from drum storage to hard drives. Hard drives are surprisingly old, by the way, just a five years younger than magnetic tape. (They were introduced by IBM in 1956.)