Learning Computer

 How to learn Computer

 

The internal architectural design of a computer system may differ for various Commercial models. However,

A logical organization exists common to all computers. This organization consists of basic components that work in complete synergy with each other to fulfil the following process.

I. Accept data

2. Process data

3. Deliver data

 

BASIC COMPONENTS OF A COMPUTER SYSTEM

A typical computer system consists of the following three basic components: the input unit, the central processing unit (CPU) and the output unit.

INPUT UNIT

The input unit is responsible for accepting data and instructions and supplying it to the computer system. 

It functions as initial link between the external environment and the computer. 

• A computer needs data to process, what can only come from the outside world. The input unit operates to accept the input data from the user. The data can be in the form of numerals, text, actions, commands, images, audios, videos etc. 

• A computer can only understand data in machine language. Hence, the input unit also consists of interfaces that convert the accepted data into a machine language. 

• The input unit is made up of a physical device, which can detect data, and an accompanied software, which can transform the data into a language that the computer can understand. For example, input devices such as keyboard, mouse, webcam and microphone operate to accept data from the computer. 

These devices can convert the user data into binary machine language.

Central Processing Unit 

The central Processing Unit, or CPU, acts as the brain of a computer. It receives data provided by the input unit and processes it according to the user's instructions. 

CPU

The CPU consists of the following three basic elements. 

Memory Unit 

To process data, the CPU must hold the data at one place. It may store the data temporarily or permanently. 

The memory unit of the CPU receives data sent by the input unit and stores it. The memory unit inside a CPU also stores the intermediate results created during the processing of data and the final result that appears once the processing is complete. 

The memory unit keeps supplying data to the processing element of the CPU. 

Arithmetic Logic Unit or ALU 

The ALU unit accepts data from the memory unit. Here, the data is subjected to arithmetic and logical operations, as instructed by the user. All calculations involving the data take place within the ALU. It is also the place where decisions are taken, based on logical comparisons of data. 

Once the processing is over, the final results are sent to the output unit of the computer.

 

Control Unit

 

The control unit in the CPU is responsible for coordinating the task between components of the computer system. It controls all internal and external devices. It also activates and controls the various operations in a computer.

 

Output Unit 

The output unit of a computer system is responsible for delivering data. I accepts the result of the data processing from the CPU. The output devices and the associated programs, convert the result into a language that users can understand. Hence, the output unit completes the cycle that the data goes through in a computer system.

HARDWARE AND SOFTWARE 

Any component of a computer system is either termed as a hardware or software. Hardware components operate in conjugation with software components to produce a result.

Hardware 

The physical part of a computer system is referred to as hardware. Hardware devices can be seen and physically touched. Primary examples of computer hardware include keyboard, monitor, hard driver processor, mouse, printer, etc.

Software 

A computer software is a collection of instructions written in a specific machine language. These instructions control the workings of the computer and all its hardware. 

A software does not have a physical presence. However, the instructions that constitute a software need to be located on a physical medium. Hence, a software needs a hardware to function. 

Software can be classified into system software and application software. Operating System, which controls the basic functioning of the computer, is a system software. Ubuntu, Windows 7 or Mac OS are examples operating systems. Application software are programs developed to perform a specific task. Word processors, web browsers and video players are application software. Examples of application software include Microsoft Word, Google Chrome, VLC media player, etc.

INPUT, OUTPUT AND STORAGE DEVICES 

The basic process of a computer system includes the central processing unit interacting with other hardware devices. These devices include the input devices, output devices and the storage devices. Together these allow the transfer of data from user to computer, from computer to user and sometimes, from one component of the computer to another. 

Input Devices 

An input device is a hardware component that allows you to send data or instructions into a computer. 

Based on the manner in which data is collected, there are following different types of input devices. 

Typing Devices 

A typing device is used to enter text or commands directly using physical buttons. However, typing the input data can be time-consuming and prone to human error. 

Examples of typing devices include keyboard, touchpad, etc. 

Pointing Devices 

A pointing device collects the input data by sensing the movement of the user. Most popular pointing devices include mouse, trackball, joystick, etc. 

Optical Devices 

An optical device allows the computer to take input in the form of images. These devices are also used for face recognition, finger print recognition, retina scanning, etc. Example of optical devices, are digital camera, web camera and scanner, barcode reader, etc. 

Audio Devices 

An audio device collects sound and converts it into digital audio data that a computer can recognize. 

Microphone is the most commonly used audio input device. 

Output Devices 

An output device receives the result of the processed data and converts it into a new medium. These devices can send data from one computer to another device or to the user. An output device simply acts as an intermediary between the computer-language and the human-language. 

The data received from the computer can be expressed in the form of a visual display, an audio or a physical production. The following are the different types of output devices that offer output in different forms. 

Display Devices 

The display devices in a computer system provide an output in the form of visual display. Visual display is generally the primary form of output from a computer system. 

For a display device, the information is displayed on the screen in such a manner that the user can read or see it. 

• A display device offers the visual output of a data, which is also referred to as a temporary data copy or soft copy. Such output is produced in the form of text, image or video on screen. 

• Most display devices are light based devices, known as Visual Display Unit or VDU. Examples of such devices include the television sets, computer monitors, head mounted displays, projectors, mobile screens, etc. 

• Display devices give temporary form of output, which gets displayed only in the presence of electricity. 

Printing Devices 

A printing device provides a permanent, tangible output of data. Such type of output is referred to as the physical output or the hard copy of data. It is an output that you can touch and hold. Printing a COPY Of the required data is the most common method of obtaining physical output. 

Printer is an output device extensively used for the same purpose. 

• A printing device offers physical copies of data to help you view the data, even when the computer system is not operational. 

• A printing device creates physical copies on printable material, which are costly, Any changes to be made to the data cannot be made on the physical copy and requires the user to access the digital copy again, 

Hence, making changes in data in case of physical output is a time-consuming and costly process. 

Audio Devices 

An audio device converts digital audio data into a sound that the user can hear. An audio device helps you to listen to music or any other sound. These devices also help the user to interact with the computer system by producing sounds that work as error alerts, system issue or security warnings. 

An audio output device in a computer system requires a specialized component, often identified as a sound card, It converts information from digital audio files into electronic sound signals, An audio device such as a speaker or headphone can covert such signals to physical sound waves. Hence, an audio card is also referred to as an audio device. 

Storage Devices 

Data storage is the fundamental action performed by a computer system. Data can be stored temporarily or permanently so that computer can access it and process it further, if required. 

The hierarchy of data storage depends on the period for which the data is stored and the speed at which it is to be accessed. Based on these criteria, storage devices store data either as primary memory or secondary memory.

The CPU of a computer system maintains the storage of data, whether received or created. This stored data may comprise instructions or data associated with programs that are currently running, Based on the retention period of the data, computer memory is categorized into the following. 

» Primary Memory 

» Secondary Memory 

Primary Memory 

Also known as the main memory, the primary memory of a computer system stores data that is being currently used, Data from the primary memory is used, when executing a program code. In such cases, the CPU tends to store data nearby for easy and quick access. The primary memory refers to those locations in the CPU, where the point-of-call is made for data retrieval. 

Primary memory is instrumental in ensuring optimal performance of the active programs, It provides quick access to data that the running/active program needs. 

Primary memory in a computer system can be Random Access Memory or RAM or it can be Read Only Memory or ROM.

Random Access Memory (RAM) 

The Random Access Memory or RAM stores active data in randomly selected memory locations. 

 

RAM

A running program may use RAM to store intermediate data, before the final result is obtained. In case the computer is powered off, the data stored in RAM is lost. 

A typical personal computer contains 1-4 Gigabytes of RAM, the size of which can be higher in more advanced machines. 

Read Only Memory (ROM) 

The Read Only Memory or ROM represents the non-volatile form of primary memory. It is the permanent memory location, where the instructions for essential, read-only operations are stored.

  

ROM

The programs or instructions stored in ROM cannot be erased by other programs. These instructions are essential for a computer to work, including 

the boot instructions. ROM is located in the computer's motherboard as a small group of semiconductors. 

Secondary Memory 

The secondary memory in the CPU represents the memory locations that store the data which is currently not in use, it is also known as permanent memory. The data stored in the secondary memory is retained for long-term and is regularly accessed by the primary memory through special input-output operations. 

HDD

 

The secondary memory is also known as auxiliary memory, as it retains data until it is removed or overwritten. The secondary memory is maintained with specialized devices using magnetic, optical or flash storage methods. 

 

SSD

Examples of secondary memory include the data stored in magnetic disks of the Hard Disk Drive or in the flash memory of a Solid State Drive (SSD). A typical personal computer may contain up to few hundred gigabytes of secondary memory storage space, which is expandable up to multiple terabytes. 

MOTHERBOARD 

Also referred to as a system board, the motherboard is one of the most essential parts of a computer. It is the main circuit board that acts as the central communication backbone. It connects the CPU with available input and output devices. 

Mother Board

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