Second Generation

Second Generation (1959-1964*): Transistor Based

The second generation saw several important developments at all levels of computer system design, from the technology used to build the basic circuits to the programming languages used to write scientific applications.The second generation of computers utilized transistors instead of vacuum tubes. A transistor is a semiconductor device used to amplify and switch electronic signals and power. Transistors replaced the vacuum tubes and piloted the second generation of computers. The advantages of transistor over vacuum tube allowed computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. In this generation, magnetic cores were used as primary memory and magnetic tape and magnetic disks as secondary storage devices.  Second-generation computers still relied on punched cards for input and printouts for output. In this generation, assembly language and high-level programming language like FORTRAN, COBOL were used.

Second-generation computers moved from cryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology.

The first computers of this generation were developed for the atomic energy industry.

Some computers of this generation were:

• IBM 7030 – IBM´s 7000 series mainframes were the company´s first transistorized computers. At the top of the line of computers — all of which emerged significantly faster and more dependable than vacuum tube machines — sat the 7030, also known as the “Stretch.” Nine of the computers, which featured a 64-bit word and other innovations, were sold to national laboratories and other scientific users. L. R. Johnson first used the term “architecture” in describing the Stretch.
• PDP-1 – The precursor to the minicomputer, DEC´s PDP-1 sold for $120,000. One of 50 built, the average PDP-1 included with a cathode ray tube graphic display, needed no air conditioning and required only one operator. It´s large scope intrigued early hackers at MIT, who wrote the first computerized video game, SpaceWar!, for it. The SpaceWar! creators then used the game as a standard demonstration on all 50 computers.

*Please note: the exact time frame of years mentioned for each generation is subject to some scrutiny, exact dates vary from source to source. For the consistency of this project, I have used the dates from the textbook being utilized in Class: Technology In Action, Complete (10th Edition) by Alan Evans, Kendall Martin (Author), Mary Anne Poatsy (Author)