Components of a computer

Facts about computers

Computer Basics | What is RAM Memory?

The ram

Currently RAM is measured in megabytes and gigabytes. A typical computer system will have from 256MB to 4MB installed. The general rule of thumb is that the more memory you have installed the faster the system will be.

Most modern computer systems have the capacity for more RAM to be added up to a maximum. The maximum allowed and the particular type and specification of the RAM will be found in the manual for the motherboard.

Alan Turing

Alan Turing was a logician, mathematician and computer scientist. He is generally known for his work in artificial intelligence and computer science.
  • Turing was born in London in 1912, and at school was able to solve complex problems without having been taught them.
  • Once he cycled almost 100 km from his home to school as the General Strike was on.
  • In 1936, he came up with the idea of a machine that was able to compute anything that could be computed. This was known as the Turing Machine and led to the modern computer.
  • During world war 2, Turing worked at Bletchley Park and was involved in breaking German codes.
  • Turing often ran 60 km to London for meetings, and he liked to chain his coffee mug to a radiator at Bletchley Park to stop other people using it.
  • During the late 1940s he worked in the University of Manchester in mathematics and computing. His experiment, the Turing test tried to devise an intelligence standard for technology.
  • In 1948 he wrote a chess programme for a computer that had yet to be invented. He also published several important papers on mathematical biology.
  • He worked on standards for machines to be called intelligent. The same principle is used today in online CAPTCHA tests, which determine whether a user is a person or a machine.
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    How Does a Touch Screen Work?

    Touch screens

    Touchscreen technology prior to the iPhone used the “resistive” method. The idea behind the “resistive” method is quite simple: two thin layers, usually made of tough plastic, are spaced a miniscule distance apart with electricity running in between. The screen is above the upper layer and the LCD display is below the bottom layer. When the screen is pressed, it forces the top layer against the bottom layer so sensors can detect where the two meet. One of the best conveniences of this method is that it can detect touch from anything that presses down on the layers, whether it is a finger or a pen cap. However, this method can only recognize one point of contact because only one point can be fully depressed at a time and as a result, does not have smooth sliding and dragging motions (“Touchscreens”). Although this method is now considered largely outdated due to the mass market of iPhone technologies, it is still used on some ATMs and in-car screens.

    Tim Berners-Lee




    Time Berners-Lee made the first communication between an HTTP (Hypertest Transfer Protocol) client and server through the internet in November 1989. He invented the World Wide Web.

    He received a knighthood in 2004 from Queen Elizabeth II.

    He is the director of the World Wide Web Consortium (W3C) a group set up to oversee the development of the World Wide Web.

    He was honoured during the opening ceremony of the 2012 Summer Olympics in London.

    He was born on 8th June 1955 in London.

    In 2001, Tim Berners-Lee became a Fellow of the Royal Society.

    He was a very keen trainspotter when he was a child and he enjoyed playing with model railways.

    He has admitted that the pair of slashes (//) in web addresses ended up being unnecessary. He said he could have designed URLs without them, but didn’t realise at the time.

    He was one of Time Magazine’s ‘100 Most Important People of the 20th Century’.

    He is sometimes referred to as TimBL.

    World Wide Web Turns 25: Inteview with inventor Sir Tim Berners-Lee

    The four generations of a computer

    The first Generation (1945 - 1955)
    - Very large computers made up of vacuum tubes and often programmed using wiring plugboards
    - Programmed using machine language
    - Mostly used for numerical calculations as working out mathematical tables
    - No OS

    The Second Generation (1955 - 1965)
    - Mainframes made up of transistors
    - Mainframes made up of transistors
    - At first punch cards were used to provide input, then tapes were used (for batch processing)
    - Used Assemblers and FORTRAN compilers for program writing
    -Simple batch processing was used with input files, programs and output on tape
    - Smaller computers (e.g. IBM 1401) was used to read programs and data on punch cards on to input tapes and for offline printing
    - Used mainly for scientific and engineering applications
    - FMS () and IBM IBSYS as OSs for handling jobs (e.g. to read a job and to run it)

    The Third Generation (1965 - 1980)

    -Mainframes based on small scale ICs were used.
    - Capable of multiprogramming (running several jobs at the same time)
    - Fixed disks were used and new jobs on cards to be executed could be read on to the disk while executing other jobs (spooling)
    - Though the first models used multiprogrammed batch processing, to cater to increased response time, timesharing was introduced later (Time-sharing Systems)
    - Complex OSs as OS/360 were used.
    - Used for various applications including scientific and business applications
    - Mini computers also appeared on the market which were used by small departments etc. and became the platform for UNIX.

    The Fourth Generation (1980 . . . )
    - Mainframes, Minicomputers, Workstations, Personal Computers (Desktop and portable) based on VLSI components
    - Network operating systems that facilitate file sharing, remote logging etc. and Client Server computing.
    - Distributed OSs that make use of multiple machines and processors to run applications.
    - GUI based OS interfaces and applications.
    - Virtual Machines and Network Computers (NCs