1962: Thin-film memory commercially available

Univac 1107 Thin-Film Memory computer announced

 

 

 

In the early 1960s thin film memory arrays offered significantly faster performance than mainstream magnetic core technology. Vacuum-deposited dots of ferromagnetic alloy material on glass substrates were overlaid with a multilayer grid of connecting wires that served as drive and sense lines similar to those of a magnetic core array. Sperry Rand developed the technology under a National Security Agency contract and announced its commercial availability in the Univac 1107 Thin-Film Memory Computer in 1962. In this application a 128-word thin-film general register stack achieved a cycle time of 600 nanoseconds compared to 4 microseconds of the 16,384 36-bit word main memory. The Univac design and others by RCA and Hughes also served in airborne computer applications.

In 1968, IBM announced the formal acceptance of two System/360 Model 95 super-speed computers. Equipped with “ultra-high-speed thin-film memories,” the Model 95 incorporated “over a million characters (bytes) of information stored on magnetic spots four millionths of an inch thick” in a cache memory that worked together with four megabytes of core. With an access time of 67 nanoseconds, this was claimed to be the fastest, large-scale memory in user operation. This same machine also employed IBM’s first monolithic integrated circuit (IC) memory, the SP95 16-bit, system-protect array.

IBM built a new plant at Essex Junction near Burlington, Vermont to fabricate thin-film memory devices. When semiconductor technology surpassed the performance and cost of thin-film, the facility was converted to high volume manufacturing of ICs. The company’s investment in thin-film research paid dividends in 1979 when the technology was adapted to produce head structures for the IBM Model 3370 disk drive, replacing heads based on solid ferrite technology.