Probably the oldest surviving secondary storage method is magnetic tape, which we will not discuss in detail in this chapter since its method of operation is very similar to a disk drive. Today's tapes are much smaller and thinner than the giant wheels of old which defined in the public's imagination what a computer looked like. Blinking lights, which were never very useful, are also gone, making today's computers extremely boring! Only the flashy graphics on the monitor hint at the depths of complexity inside.

Tapes are still useful because a huge amount of data can be stored on a tape cartridge, making them ideal for backups. But they are very slow to use since accessing a random word of data from the tape might require rewinding the entire tape, a very time-consuming process. It is almost ludicrous that some of the earliest operating systems, called TOS (Tape Operating System), relied upon tapes for out-of-RAM storage.