Tape Libraries

A tape library is a storage device that contains one or more tape drives, a number of slots to hold tape cartridges, a barcode reader to identify tape cartridges, and an automated method for loading tapes. It is also sometimes referred to as a tape silo, tape robot, or tape jukebox. A tape library is not just the place where tapes that are not currently being held in a silo are kept, but it is also the name of the location. Tape libraries have the capacity to store millions upon millions of tapes.

The IBM 3850 Mass Storage System (MSS), which was introduced in 1974, is considered to be one of the early instances.

The Mercury Delay Line Memory

The mercury delay line was a method for representing binary zeros and ones as pulses of acoustic energy that relied on sound waves flowing through a tube of mercury. At the very least, in principle, the pulses could travel through the delay line unbrokenly if they were to capture the sound waves at the other end of the line and then feed them back into the beginning. This meant that data bits were stored within the system so long as the power was maintained and there was no interference with the usual operation of the system. Around 500 bits of information might be stored in a single delay line at any given time. Although it was more dependable than radio valve logic, a drawback was that each delay line required 20 kilograms of mercury to operate. Be thankful that computers no longer use this technology; if they did, a modern laptop with even a relatively modest memory of 4 gigabytes would mostly weigh more than 1.3 million metric tonnes.

Magnetic-core Memory

The term “magnetic-core memory” refers to any one of a class of computer memory devices that consists of a large array of tiny toruses made of a hard magnetic material that can be magnetised in either of two directions. Other names for this type of memory include “core memory” and “magnetic-core storage.” Both of these directions have the potential to represent either the value 0 or the value 1 in a binary bit. In the 1950s, magnetic core memory began to see extensive use, but by the 1970s, it had been mostly rendered obsolete by semiconductor memory chips.