Second Generation Computers


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IBM 1401


    By 1948, the invention of the transistor greatly changed the computer's development.  The transistor replaced the large, cumbersome vacuum tube in televisions, radios and computers.  As a result, the size of electronic machinery has been shrinking ever since.  The transistor was at work in the computer by 1956.  Coupled with early advances in magnetic-core memory, transistors led to second generation computers that were smaller, faster, more reliable and more energy-efficient than their predecessors.  The first large-scale machines to take advantage of this transistor technology were early supercomputers, Stretch by IBM and LARC by Sperry-Rand.  These computers, both developed for atomic energy laboratories, could handle an enormous amount of data, a capability much in demand by atomic scientists.  The machines were costly, however, and tended to be too powerful for the business sector's computing needs, thereby limiting their attractiveness.  Only two LARCs were ever installed: one in the Lawrence Radiation Labs in Livermore, California, for which the computer was named (Livermore Atomic Research Computer) and the other at the U.S. Navy Research and Development Center in Washington, D.C.  Another addition in second generation computers was the introduction of assembly language.  When assembly language replaced machine language,  abbreviated programming codes to replaced long, difficult binary codes (Gersting 35).

    Throughout the early 1960's, there were a number of commercially successful second generation computers used in businesses, universities, and government from companies such as Burroughs, Control Data, Honeywell, IBM, Sperry-Rand, and others.  These second generation computers were also of solid state design, and contained transistors in place of vacuum tubes.  They also contained all the components we associate with the modern day computer: printers, tape storage, disk storage, memory, and stored programs.  One important example was the IBM 1401, which was universally accepted throughout industry, and is considered by many to be the Model T of the computer industry.  By 1965, most large business routinely processed financial information using second generation computers (Gersting 218).

    It was the stored program and programming language that gave computers the flexibility to finally be cost effective and productive for business use.  The stored program concept meant that instructions to run a computer for a specific function (known as a program) were held inside the computer's memory, and could quickly be replaced by a different set of instructions for a different function.  A computer could print customer invoices and minutes later design products or calculate paychecks. More sophisticated high-level languages such as COBOL (Common Business-Oriented Language) and FORTRAN (Formula Translator) came into common use during this time, and have expanded to the current day.  These languages replaced cryptic binary machine code with words, sentences, and mathematical formulas, making it much easier to program a computer.  New types of careers (programmer, analyst, and computer systems expert) and the entire software industry began with second generation computers (Gersting 131).