Memory

historical background

Magnetic-core memories were predominantly rampant in the 1960s and 1970s, but today they are rare. The first who searched for an alternative non-volatile memory were An Wang, who was born in Shanghai, and Jay Forrester. One important invention was the 'write-after-read- cycle'. Wang had this patented. This patent became valid in 1955 and IBM (International Business Machines Corporation) had to buy it from Wang, because they already used it a few years before.

The magnetic-core memory reached its final form after further inventions. The most important was the 'coincident-current system' by Jay Forresters, which allowed to put many magnetic- cores in a memory with just a little number of wires (arranged in a matrix). By the end of the 1950s, the magnetic-core memories were menufractured by hand in asian factories.The manufracturing process was never automated. The cots of this process, which were high in the beginning, decreased with the market development. The magnetic-core memories were applied in the usual computing machines. A well-known producer was, for example, IBM.

By the mid-1970s, the magnetic-core memories were displaced by the semiconductor memories.