In this section lets learn what are components and types of computer systems available.

  1. What is Hardware?
    • Hardware is a general term for the physical components that make up a computer system.  e.g.,
      • Keyboard
      • Mouse
      • Circuit Board
  2. What is Software?
    • It is a general term for the programs that control the computer system
  3. What are the types of software?
    • Theres are two types of softwares:-
      • System software
        • Programs that allow the hardware to run properly.  e.g., MS DOS, Windows, etc
      • Application Software
        • Programs that allow the user to do specific task.  e.g., Excel, Powerpoint, etc
  4. What are the main components of a computer system?
    1. CPU – The important part is CPU which interprets and executes the command from the computer hardware and software.
    2. CPU is made of different components and numerous small ICs which were combined together on one or more circuit boards.
    3. However, due to modern manufacturing techniques, the term microprocessor is now used instead of CPU.
    4. This is a single IC which is at the heart of most PCs and is also found in many household (appliances) devices and equipment where some control or monitoring is needed.  E.g., Fridge, TV, Washing Machine, car, calculator, etc
    5. RAM – RAM is an internal chip where data is temporarily stored when running apps.  This memory can be written to and read from since its contents are lost when power is switched off.  It is also known as volatile or temporary memory.
    6. ROM – ROM is a memory used to store information that needs to be permanent.  It is often used to contain, for example, configuration data for computer system.  These chips cannot be altered and only be read from.
    7. One of the advantage is that the information stored on the ROM is not lost even when power is switched off.  They are also known as non-volatile memory or permanent memory.
    8. BIOS ROM – This also contains some coding known as the boot file.  This code tells the computer what to do when it first starts up, it is often referred as BIOS (Basic Input Output System).  When the computer is turned on, the BIOS carries out a hardware check to find out if all the devices are present and whether they are functional then it loads OS in the RAM.  The BIOS stores the date, time and system configuration in a non volatile chip called CMOS (Complimentary Metal Oxide Semiconductor) which is battery powered.
  5. What is an OS?
    • OS enables users to communicate with computer systems.  The general tasks for OS include :
      1. Controlling the operation of input, output and backing storage devices.
      2. Supervising the loading, running and storage application programs.
      3. Dealing with the errors that occur in the application programs.
      4. Maintain the security of the whole computer system.
  6. What is an interface?  What are the various types?
    1. Computer users need to be able to communicate with the Operating System.  This is called the user interface.
    2. There are two types of interfaces:-
      1. CLI (Command Line Interface):-
        • CLI require the user to type in instructions in order to perform operations.   There are number of commands that need to be typed in, for example, save, edit, create.  The user therefore, has to learn a number of commands first to carry out basic operations.
        • The advantages of CLI is that user is in direct communication with the computer and is not restricted to predetermined options.
      2. GUI (Graphical User Interface):-
        • It allows the user to interact with the computer using pictures (icon) or symbols rather than having to type into number of commands.  GUI use various technologies and devices IO provide user interface.
        • One of the most common keys windows, icons, menus and pointing device (WIMP) which was developed for use on personal PCs.  This uses a mouse to control a cursor which then selects icons to open or run windows.
        • Each windows contains an application and modern computer system allow several windows o be open at the same
        • In recent years, devices such as touch screen phones use post WIMP interaction were fingers are in contact with the screen.  This allows actions such as rotating which would be difficult to do using a single pointing device such as a mouse.
  7. What are the types of computers?
    1. There are many types of computers:-
      1. PC/Desktop
        • It refers to a general purpose computer which is made of separate monitor, keyboard, mouse and processor unit.  The term PC usually refers to computer systems which are IBM compatible thus distinguishing them from Macintosh machines.
        • Advantages
          • Spare parts and connections tend to be standardised which usually results in low cost.
          • Desktops have better specifications (faster processors) for a given price.
          • The casing allows good dissipation of any heat that might buildup.
        • Disadvantages
          • Desktops are not particularly portable since they are made up of separate components.
          • All the components need to be connected by wires which can be quite complex and take more space.
          • Because they are not portable, it is necessary to copy files when you do your work elsewhere.
      2. Laptop
        • Laptop refers to the type of computer where the monitor, keyboard, mouse, processor are all together in a single unit. This makes them extremely portable.  The key features are Low weight, low power consumption and Processor which does not generate more heat.
        • Advantages
          • They are very portable.
          • No trailing wires.
          • Advantages of WI-FI.
          • Since they are portable, they link into any multimedia system.
        • Disadvantages
          • They have limited batter life so user needs to carry a heavy adapter.
          • Since they are portable, they are easy to break.
          • Keyboard and pointing devices are awkward to use.
          • Generates more heat than desktops.
      3. Netbook
        • It is a term used to describe a computer that can almost fit in the hand and is a smaller version of a laptop.
        • Advantages
          • Netbook computers have many of the same features of a laptop and therefore have similar advantages and disadvantages.
          • They use a touch screen and often a stylus.
        • Disadvantages
          • They don’t have CD or DVD drives.
        • The keyboards are almost 80% the size of laptops.
        • They lack some of the features found in smaller machines due to size constraints and the fact that they are cheaper to purchase.
        • PDA is similar to a palm top computer except that it is smaller and that it has no keyboard, using a touch screen for all data input.  Since the screen is small, PDAs have a small stylus (plastic stick) that is used to press the thing on the scren.  Most PDAs use a handwriting recognition system, to allow the user to write on the screen and the writing converted into computer text.  PDAs are often called pocket PCs. PDA (Personal Digital Assistant)


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