Magnetic tape drives

Introduced by IBM in the 1950s, magnetic tape was an easy and very fast way to store data at a speed equal to its processing time. The IBM 726 magnetic tape reader and recorder was one of the first devices to offer this storage, with a capacity or tape density of 100 bits per linear inch of tape. Inch of tape should give an indicator of the size of the tape, which was wound on a large wheel, similar to old film roll movie tape.

With magnetic tape media, data is written across the width of the magnetic-coated plastic strip in frames separated by gaps consisting of blocks. Magnetic tape is still very much used today, and like many other storage media types has significantly decreased in size while increasing capacity and speed.

To give an idea of how far magnetic tape storage has come as of 2017, IBM has developed newer tape storage media with a tape density of 200 Gbps per inch on a single cartridge, which can record up to 333 GB of data. These cartridges (for older folks like myself) are the size of a cassette tape, or (for the younger ones) not much smaller than the average smartphone, which fits in your hand.