early 1970s and used in several video games and game systems (e.g. the Arcadia 2001). and in the early telesoftware broadcasts. The Signetics 8X300 was a bipolar microprocessor developed by Scientific Micro Systems but manufactured by Signetics starting in 1976. It was mostly used as a controller chip due to its limited instruction set and its high speed. The Signetics 2513 was a character generator chip used in the TV Typewriter, Apple I, and early versions of the Apple II, as well as Atari's earliest arcade games. The Signetics 82S100 FPLA (Field Programmable Logic Array) was the first commercially successful user programmable logic device, the forerunner of the modern FPGA. NE5532, a widely used audio op amp, now generic and produced by many other manufacturers. According to one 1993 article, NE5532 was "the standard audio op amp to which others are compared". NE5517, an operational transconductance amplifier, still in production by NXP Semiconductors and also generically made by other manufacturers; it is given as a classic OTA example in a number of textbooks. See also Write-only memory (joke) References Further reading Lécuyer, C. Making Silicon Valley: Innovation and the Growth of High Tech, 1930-1970, MIT Press, 2006. External links Signetics.com: official Signetics website Chipdb.org: Signetics Defunct semiconductor companies of the United States Defunct computer companies of the United States Defunct computer hardware companies Assembly and Test semiconductor companies Companies based in Silicon Valley Technology companies based in the San Francisco Bay Area American companies established in 1961 American companies disestablished in 1975 Computer companies established in 1961 Computer companies disestablished in 1975 Electronics companies established in 1961 Electronics companies disestablished in 1975 Technology companies established in 1961 Technology companies disestablished in 1975 1961 establishments in California 1975 disestablishments in California Philips Defunct companies based in the San Francisco Bay Area 1975 mergers and acquisitions NXP Semiconductors