Back to: Jss1 Computer Science – ICT (BST)

Concept of Computer

A computer can be defined as a collection of electronic and electromechanical devices that have the capability to accept data or information, process it, store it, and produce output according to sets of instructions known as programs.

The functional organization of a computer to execute all the stages involved in data processing commonly referred to as Input Process Output (IPO), can be illustrated using a pictorial representation as shown below. This diagram highlights the various components of a computer system and how they work together to enable the processing of data.

The input stage involves the provision of data or information to the computer system. This can be accomplished through input devices such as keyboards, mice, scanners, and microphones. The data provided is then processed by the computer system in the processing stage, which involves the execution of sets of instructions or programs.

The processing stage is where the computer system performs all the necessary calculations and manipulations on the provided data. This is accomplished by the central processing unit (CPU), which is the brain of the computer system. The processed data is then stored in the computer’s memory for future reference.

The output stage involves the provision of the processed data in a format that is useful to the user. This can be accomplished through output devices such as monitors, printers, and speakers. The output produced is the result of the processing stage and can be in the form of text, images, or sounds.

The IPO model provides a clear understanding of how a computer system functions and highlights the importance of each component in the processing of data

The Parts of Computer

1. Input Devices: Input devices are the tools that enable one to transfer data and information into a computer system. These devices can be a keyboard, sensors, joystick, mouse and pad, scanner, multimedia microphone, light pen, web camera, touch screen and other similar devices.
2. Processing Device: Also known as the processor, the processing device is the computer system’s brain that works on the data that is fed from the input devices. The processor, along with other computer components, forms the Central Processing Unit or CPU. The CPU is housed in a casing or box, which can be either horizontal (desktop) or vertical (tower top) and is mounted on the motherboard. The processor is a logical circuit that processes and responds to the fundamental instructions that operate a computer. The Central Processing Unit is made up of three main units: the Control Unit, Arithmetic Logic Unit, and Memory Unit.
3. The Control Unit: This unit is responsible for coordinating and directing the activities of the other elements of the system as directed by the program in storage. Additionally, it directs control signals between the CPU, input, and output devices.
4. The Arithmetic and Logic Unit: The Arithmetic and Logic Unit has two subunits. The Arithmetic Unit performs mathematical operations like addition, subtraction, multiplication and division. The Logical Unit, on the other hand, performs logical operations like data comparison, such as determining if one set of data is greater than, less than or equal to another set of data.
5. The Memory Unit: The Memory Unit, also known as Main Memory, is used for storing data that needs to be processed, as well as instructions for processing.

Types of processor

In the realm of computer microprocessors, two major manufacturers are Intel and Advanced Micro Devices (AMD).

1. Intel produces several types of desktop CPUs including Celeron, Pentium and Core, while AMD’s desktop processors include Sempron, Athlon and Phenom. For notebooks, Intel manufactures mobile processors like Celeron M, Pentium M, and Core.
2. Advanced Micro Devices AMD also offers mobile versions of its Sempron and Athlon processors, as well as the Turion mobile processor, which comes in both Ultra and Dual-Core versions. It’s worth noting that both companies produce both single-core and multi-core processors, providing options for a wide range of computer users.

Features of the Processor

1. Every processor is characterised by a clock speed, measured in gigahertz, and a front side bus that links it to the system’s random access memory (RAM). Additionally, a CPU usually features two or three levels of cache memory.
2. Cache memory is a form of rapid access memory that functions as a buffer between the processor and the RAM. Its purpose is to improve the efficiency of data retrieval and transfer by holding frequently accessed data in a location that can be accessed more quickly than the main memory. This allows the processor to access data more rapidly and minimises the number of times it must wait for data to be fetched from the slower, larger RAM. By using cache memory, processors are able to perform computations more quickly and efficiently.                                                                           

The Function of The Processor

1. A processor is a silicon chip that contains millions of tiny transistors which process the instructions or operations within computer programs that can be executed. The Central Processing Unit (CPU) processes information at a rate that varies depending on the speed of the processor and the amount of Random Access Memory (RAM) available.
2. The processor is the brain of the computer, responsible for carrying out the tasks required by the software running on the system. The more powerful the processor, the faster the computer can execute tasks and the more complex programs it can handle. In order to keep up with modern computing demands, processors have become increasingly sophisticated and powerful, with more and more transistors being packed onto each chip.
3. The processor speed is measured in gigahertz (GHz), indicating how many cycles per second the processor can execute. The higher the clock speed, the more instructions the processor can handle in a given amount of time. However, a faster clock speed also means that the processor generates more heat, which can lead to stability issues if not properly managed.

Output Devices

Output devices are responsible for displaying or providing the results of processed inputs, either through a monitor (VDU) or other devices. Once data has been processed by the computer, output devices display or produce the result in a format that can be easily understood by the user. Common output devices include monitors, printers, projectors, plotters, multimedia speakers and more.

1. Monitors are the most common output device, providing a visual display of text, images, and other graphical elements. Monitors come in different sizes and resolutions, from small screens on laptops to large, high-resolution displays for professional use.
2. Printers are another important output device, producing physical copies of text and images. There are many different types of printers available, including inkjet, laser, and dot matrix printers. Each has its own advantages and disadvantages, depending on the intended use and printing needs.
3. Projectors are used to display images and video on a larger screen or surface, making them ideal for presentations and other multimedia applications. Plotters, on the other hand, are used for creating large-scale prints and drawings, such as engineering blueprints and architectural plans.

The Hardware of A Modern Personal Computer

1. A monitor: the monitor is a visual display unit that is used to show images and graphics on a computer. It is an important output device that allows users to interact with their computers.
2. Motherboard: The motherboard, also known as the mainboard, is a printed circuit board that houses various components of a computer system. It serves as the main communication centre for all other parts of the computer.
3. The CPU (Central Processing Unit): This is the brain of a computer system. It is responsible for executing instructions and carrying out computations that enable the computer to perform various tasks.
4. RAM (Random Access Memory): This is a type of computer memory that is used to temporarily store data and information while the computer is running. It is a volatile memory, which means that it loses all data when the computer is turned off.
5. Expansion Board: An expansion card is a printed circuit board that can be added to a computer system to provide additional functionality. It can be used to add features such as sound, graphics, and networking capabilities.
6. Power Unit: The power supply is an internal component of a computer system that provides power to all other components. It converts AC power from the wall outlet into DC power that is used by the compute
7. optical disk drive: An optical disk drive is a hardware device that is used to read and write data to optical disks, such as CDs and DVDs. It allows users to play music, watch movies, and install software from these types of disks.
8. The hard disk: The hard disk is a non-volatile storage device that is used to store and retrieve digital information. It is the primary storage device for most desktop and laptop computers.
9. A keyboard: A keyboard is an input device that is used to type text and commands into a computer system. It contains a set of keys that are arranged in a specific layout.
10. A mouse: A mouse is an input device that is used to navigate and interact with a computer system. It allows users to move a cursor on the screen and select or click on items.