Thin-film memory is a high-speed alternative to

core memory Core or cores may refer to: Science and technology * Core (anatomy), everything except the appendages * Core (manufacturing), used in casting and molding * Core (optical fiber), the signal-carrying portion of an optical fiber * Core, the centra ...

developed by

Sperry Rand Sperry Corporation was a major American equipment and electronics company whose existence spanned more than seven decades of the 20th century. Sperry ceased to exist in 1986 following a prolonged hostile takeover bid engineered by Burroughs ...

in a government-funded research project. Instead of threading individual ferrite cores on wires, thin-film memory consisted of 4-micrometre thick dots of

permalloy Permalloy is a nickel–iron magnetic alloy, with about 80% nickel and 20% iron content. Invented in 1914 by physicist Gustav Elmen at Bell Telephone Laboratories, it is notable for its very high magnetic permeability, which makes it useful as a ...

, an

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...

–

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

alloy, deposited on small glass plates by vacuum evaporation techniques and a mask. The drive and sense lines were then added using

printed circuit A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a laminated sandwich struct ...

wiring over the alloy dots. This provided very fast access times in the range of 670 nanoseconds, but was very expensive to produce. In 1962, the

UNIVAC 1107 The UNIVAC 1100/2200 series is a series of compatible 36-bit computer systems, beginning with the UNIVAC 1107 in 1962, initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation as the ClearPath Dorado Seri ...

, intended for the civilian marketplace, used thin-film memory only for its 128-word general register stack.

Military computer This article specifically addresses U.S. armed forces military computers and their use. History Some of the earliest computers were military computers. Military requirements for portability and ruggedness led to some of the earliest transistori ...

s, where cost was less of a concern, used larger amounts of thin-film memory. Thin film was also used in a number of high-speed computer projects, including the high-end of the IBM

System/360 The IBM System/360 (S/360) is a family of mainframe computer systems that was announced by IBM on April 7, 1964, and delivered between 1965 and 1978. It was the first family of computers designed to cover both commercial and scientific applica ...

line, but general advances in core tended to keep pace.

External links

* * * * * Computer memory Non-volatile memory Thin films {{nano-tech-stub