A Brief History of Chips - The Integrated Circuit Finds a Market
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Integrated circuit technology has sometimes been cited as one of the alleged spin-off benefits of the money spent by NASA on the space program. The Apollo Guidance Computer developed for the Space Program by the MIT Instrumentation Laboratory indeed made the first practical use of monolithic integrated circuits in an embedded computer -- 4100 of them in fact, each containing a single 3 input NOR logic gate in RTL (Resistor Transistor Logic) technology. While RTL logic technology had been previously implemented as discrete components, in fact IBM's 1401 computer announced on October 5, 1959 used RTL logic technology as well as the more advanced Diode Transistor Logic (DTL), both implemented as discrete components on printed circuit cards called SMS (Standard Modular System) cards by IBM. A later version of the Apollo Guidance Computer used approximately 2800 flat pack integrated circuit carriers, each of which contained two 3 input NOR gates per flat pack. The computer also had 4K words (of 15 data bits plus 1 parity bit) of erasable memory (RAM) and between 12K and 32K words of fixed memory (ROM) depending on the computer version. Wire-wrap interconnections were used to connect the socketed integrated circuits together.
The real volume driver for these small-scale integration (SSI) integrated circuits, though, was the guidance computer for the Minuteman missile program which needed these relatively small lightweight devices in quantities sufficient to push them into mass production. The Minuteman program (along with the smaller Apollo program discussed above) purchased almost all of the available integrated circuits from 1960 through 1963, driving the cost per integrated circuit from approximately $1000 (in 1960 dollars) to merely $25 (in 1963 dollars).
Oddly enough, when I was a student at MIT in 1969, a member of the MIT Science Fiction Society, Russell Seitz, announced that he had acquired the parts (except the nuclear warhead) for a working ICBM. It seems that as the solid fueled Minuteman missiles began to displace the earlier generation liquid fueled Atlas and Titan missiles, one of the earlier generation missiles was sold for scrap at auction and he had actually made the winning bid. After all of the attendant publicity, he disposed of the missile by donating it to a museum.
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