Generations of the Computer

First Generation 1946 - 1959

First Generation (1946 – 1959) Key Component – Vacuum Tubes Very large and bulky No memory Programmed in Machine Language Very expensive to run Used great amounts of power In constant repair Not reliable Input – Punch cards

Vacuum Tubes Vacuum tubes are sealed glass used in electronic circuitry to control the electrons sealed inside the tubes. They are used for: the amplification of weak currents, rectification of an altering current to direct current (AC to DC), generating of oscillating radio-frequency power for radio, radar, and more. Some of the earliest forms of a vacuum tube were recorded in the late 17th century but it wasn’t until 1850 when they created sophisticated versions of vacuum tubes. Some of the first computers were made out of vacuum tubes. (1946)

Second Generation 1959 - 1965

Second Generation (1959 – 1965) Key Component – Transistors Getting smaller & faster Built for “Specific” purposes Has memory Magnetic tape replaces Punch cards High-level computer languages (people-oriented such as BASIC & COBOL) First commercial computers Can only do 1 program at time

Transistor Created by Julius Edgar Lilienfeld. The transistor is a semiconductor used to amplify a switches electronic signals. Transistors are made with a semiconductor material with at least three terminals. They can be built very compact, more than 1,000,000 per square centimeter on a silicon chip. Replaced vacuum tubes. Transistors are what we use to make the computer code of 1’s and 0’s much faster. They can be switched on and off very rapidly by switching every 0.000000001 Seconds. By:Chris Woof Patented-1925 Used on the telephone-1947 Used on computers late 1950’s through 1960’s.

Third Generation 1965 - 1971

Third Generation (1965 – 1971) Key Component – Integrated or Etched Circuitry Mini-computers Operating speeds measured in billionth of a second Multi-processing Keyboards ‘Computer Literacy’ begins

Fourth Generation 1971 -

Fourth Generation (1971 - ) Key Component – Microprocessors (Micro Chips) Micro-computers (Personal computers) Can be mass-produced Data communication networks (Internet)

Microprocessor The microprocessor is also known as the CPU (or the brain of the computer). It is connected to the circuit board.