Second Generation Computers

Transistors

1956-1963

   Inefficiency of vacuum tubes required a new type of technology that would require less power and provide more speed. Transistors allowed computers become smaller, faster and more energy efficient. They were invented in 1947 by John Bardeen,William Shockley, and Walter Brattain. The same as the vacuum tube transistor could increase received electric energy and control output and input of the energy. Comparing to the vacuum tube, transistor is made of semiconductor, like silicon, which does not produce heat. Also, transistor is more reliable than vacuum tube. It is also smaller then the tube. Moreover, tranistor is more energy efficient. Another important disadvantage of the vacuum tube was very long preheating , which does not apply to computers using transistor. Therefore, advantages of transistor allowed to maximize speed of computers and minimize the size without increasing energy usage or cooling.

Second Generation Computer

   Another crucial change was memory. Magnetic drum was replaced by magnetic core memory made out of many small wires called cores. Each core can be magnetized two ways representing zero or one bit information. It was revolutionary technology because every core could be magnetized one to zero, which means that memory could be erased allowing for a new command. Also, It was very important that this technology allowed to recall memorized  information. Similarly to transistor technology, magnetic memory allowed more efficiency and smaller size. Magnetic memory existed until 1970. Also, magnetic disks and tapes appeared as extra exterior storage.

   Those information stored in magnetic memory were written using more complex languages than mechanical. Assembly and symbolic languages allowed programmers to describe instructions in words translated into language understandable to computers. This process called assembling was possible because of magnetic memory type. At the same time, high-level languages, like FORTRAN or  COBOL, were invented.

   Still, second generation computer were able to perform only one task at the time. They used single stream batch systems that put together data and programs in groups.

Main computers of the transistor era:

-IBM 1620
-IBM 7094
-CDC 1604
-CDC 3600
-UNIVAC 1108

IBM 7094' specifics:
-introduced in 1963
-memory: magnetic core
-CPU type: transistor
-memory size: 36 bit words
-CPU speed: 0.5 MHz
-system price: $3,134,50








Main characteristics of the first generation computers:

The Magnetic
Core Memory

How Does The Transistor Work?