First Generation Computers

• The first generation computers from 1946 to 1958 used vacuum tubes to transmit electrical signals internally. First generation computers were large because they required thousands of vacuum tubes to provide sufficient power. Computers like the ENIAC often overheated because of these tubes and required a massive air-conditioning unit to cool it down. Regardless of the gigantic cooling units, these early computers continued to overheat.
  
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Second Generation Computers

• The solution to this problem brought along with it a new generation in computer technology known as the "Era of the Transistor" from 1959 to 1964. Transistors were much faster, smaller and less expensive to build than vacuum tube computers. One transistor had the efficiency to replace roughly 40 vacuum tubes. These computers, still large and bulky, were mostly used by universities and government agencies due to overwhelming purchase costs. The Burroughs B55000 transistorized computer cost up to $5 million dollars in 1964.
  
  

Third Generation Computers

• To reduce the bulk of second-generation computers further, the invention of integrated circuits brought a new generation of computer technology. Integrated circuits, also known as semiconductor chips, are tightly compacted transistors on a single wafer of silicon. Thousands, even millions of transistors packed together in a single chip reduced the manufacturing cost and size of the computer considerably. The IBM S/360, the size of a small filing cabinet, sold at $133,000 and up, according to an April 7, 1964 IBM press release.
  
  

Technology Doubles

• Every two years after the invention of integrated circuits, the amount of transistors that could be packed together doubled, reducing the size and cost of computers even further. The reduction in cost allowed businesses to take advantage of the power of computers and forwarded the vision of the personal computer.
  
  

1960s Software

• As computers become more accessible, the demand for software rose dramatically. By the mid-1960s in the U.S. alone, 45 software companies generated $100 million in revenue. Computers came bundled with software that a customer specifically demanded -- at no extra charge. IBM kept a large library of all available programs and software for inclusion with the computer, as customers demanded. Computers in the latter half of the 1960s became favored business tools, which put pressure on software engineers to come out with programs to simplify and enhance how business was conducted.
  
  

The Evolution of Business Software

• In 1965, software contractor ADR released Autoflow, a program that instantly created flow charts out of source code to help track business trends. Mark IV, created by Informatics in 1967, simplified filing systems with its revolutionary digital file-managing and report-generating capabilities. Software engineering elevated the computer industry to a major economic component that not only made millions in revenue, but also created thousands of jobs.
  
  

Computers Then and Now

• In 1971, Intel, a major computer chip manufacture today, invented the first microprocessor. A microprocessor acted as a mini-computer and did the work of a full-scale third generation computer. This shrunk computers from the size of small filing cabinets while increasing processing power to desktop machines and eventually to laptops. To put things into perspective, third generation computers could carry out a few instructions in about a billionth of second. A single microprocessor today performs over a billion calculations in under a second and fits on your lap as opposed to taking up an entire room.