Unit 1: Introduction to Information and Society A First generation (1950s) • Used vacuum tubes as components for the electronic circuit.
• Punched cards were the main source of inputs, and magnetic grams were used for
internal storage.
• Operate in a speed of milliseconds (thousandths of a second) and could handle
more than 10,000 additions each second.
• Most applications were scientific calculations.
B Second generations (early 1960s) • Transistors were the main circuit components. (Transistors are a solid state device
made from silicon which is smaller, cheaper, faster, dissipate less energy and more
reliable than vacuum tube but work in the same way with the vacuum tube.)
• Invented by Bell Labs.
• Magnetic tapes (similar with music tape caste), used for main storage,
• Operate in microseconds (millionths of a second) with more than 200,000
additions possible each second.
• Business applications become more commonplace, with large data files stored on
magnetic tape and disk. (Magnetic disk: is a circular platter constructed of metal
or plastic materials coated with magnetizable substance.)
• High-level languages COBOL and FORTRAN were introduced during this period.
Batch operating systems are used that permitted rapid processing of magnetic
tape files.
C Third generation (late 1960s, early 1970s Characterized by solid-state logic and integrated circuit (IC). (A single, self-contained transistor
is called discrete component. In early 1960 electronic equipment composed of discrete
components transistors, capacitors, resistors, were available:
• Computer storage switched from magnetic cores to integrated circuit boards
that provide modularity (expandable storage) and compatibility (interchangeable
equipment)
• New input/output methods such as optical scanning and plotters.
• Software become more important with sophisticated operating systems, and
improved programming languages.
