Computer Hardware and Software Elements

Objectives

• Explain the parts of a computer system • Identify computer hardware. • Explain the different hardware available and their functions • Describe hardware configuration • List some input units • Describe the functions of the output units. • Describe the function of the CPU • List some auxiliary units • Describe the functions of the auxiliary memory. • Define: nibbles, bytes, word and storage size in terms of ‘k’ • Define software • List various types of software • Distinguish between low and high level languages • Define source and object codes • Identify source and object codes • Define a translator • Describe different types of translator: assembler, compiler, and interpreters. • Identify different types of translators: assemblers, compilers and interpreters.

A Computer SystemA computer system consists of different units. These units have their own functions. They are connected with each other via cables or other medium. These units are connected with a purpose of smooth operation of computer. Computer system has four major

1. Input Unit,2. Processing Unit, 3. Output Unit 4. Storage Unit.

Input UnitThe task of Input Unit is very simple – to input data into the computer. All the devices that somehow enter data in computer are input devices. We type into keyboard to enter data, click on mouse to issue commands (input commands into computers), scan images, record voice, shoot video and many ways a computer gets data into it. So, keyboard, mouse, light pen, joystick, microphone, web cam, video camera etc. all are input unit deviceIf we look a bit deeper, it is the input unit that accepts the user data, converts it in suitable form (string of binary digits) –known as encoding – so that it can be used by computer.

Processing Unit

The task of processing unit is to process data. It obtains data from input unit, performs necessary calculation, comparisons to produce the result. This unit is often called the central processing unit (CPU) and consists of three sub-units – ALU, CU & MU. Processors, co-processors, Memory cards etc. constitute this unit.

Constituent of Processing Unit• ALU stands for Arithmetic and Logical Unit. This

is the calculating unit of a computer system. The actual instructions execute in ALU. It performs mathematical manipulation, logical and comparative analysis.

• CU stands for Control Unit. It is a sub-unit of CPU that controls and directs the flow of information throughout the computer system. So, it is also known as the nerve center of a computer system. It is the job of CU to fetch instructions, decode them and execute.

Constituent of Processing Unit

Primary Memory Unit (MU)This is a part of CPU that handles the storage facilities of data. Primary memory is also known as internal memory. It is called primary memory because this is the only unit through which CPU accesses data directly. The examples of primary memory are RAM and ROM.

Output Unit

This unit provides results to the user in suitable form. A computer may output as display on monitor, projector or produce sound in speaker, or printout through printer, plotter etc. These are output devices. This unit receives data from processing unit and converts it in suitable form (decodes – contrast with encoder, the input unit) so that the output is in human readable form.

Storage Unit

Storage unit facilitates the data storage in computer so that it can be kept safe for future use.

Hard Disk

Types of Storage

There are two types of storage – • primary or main or internal storage• secondary or auxiliary or external storage Paper Tapes, magnetic tapes, floppy disk, hard

disk, compact disks, Blu-ray disks etc. are some examples of secondary storage devices.

Primary Storage

Primary storage is a storage location that holds memory for short periods of times while the computer is on. For example, computer RAM and cache are both examples of a primary storage device. This type of storage is the fastest type of memory in your computer and is used to store data while it's being used. For example, when you open a program data is moved from the secondary storage into the primary storage.

Secondary Storage

Secondary storage is a storage medium that holds information until it is deleted or overwritten regardless if the computer has power.

Exploded View of Personal Computer System

Bit

• A 'bit' (short for Binary Digit) is the smallest unit of data that can be stored by a computer. Each 'bit' is represented as a binary number, either 1 (true) or 0 (false).

Byte

A 'byte' contains 8 bits, so for example, it could be stored as 11101001. A single keyboard character that you type, such as the letter A or the letter T takes up to one byte of storage.

Nible

This is not a very commonly used term compared to bit and byte. It is the term given to a group of four bits. Therefore two nibbles make a byte.

The reason it is not very common is because most microprocessors use groups of 8bits and higher i.e. They use one or more bytes to process data. Not many devices make use of a nibble.

Software

Also known as Program or Code. Software are instructions executed by a computer, as opposed to the physical device on which they run (the “hardware“ ). Software is a set of instructions that tells the computer what to do.Software can be split into two main types: •system software•application software

Types of Software

System Software

• System software is a program that manages and supports the computer resources and operations of a computer system while it executes various tasks such as processing data and information, controlling hardware components, and allowing users to use application software.

System Management Programs

• The system management programs are programs that manage the application software, computer hardware, and data resources of the computer system

• These programs include operating systems, operating environment programs, database management programs, and telecommunications monitor programs. Among these, the most important system management programs are operating systems.

System Support Programs

• System support programs are the programs that help the operations and management of a computer system.

• The major system support programs are system utility programs, system performance monitor programs, and system security monitor programs (virus checking programs).

System Development Programs

• System development programs are programs that help users develop information system programs and prepare user programs for computer processing.

• The main system development programs are programming language translators, programming environment programs, computer-aided software engineering packages.

Examples of System SoftwareOperating Systems are the main examples for system software. Examples of OS are as follows:•Linux•Microsoft Windows•Mac OS X•DOSOther system software are following:•BIOS Software•HD Sector Boot Software•Device Driver Software i.e Graphics Drive etc•Linker Software•Assembler and Compiler Software

Application Software

• Application software consists of programs that direct computers to perform specific information processing activities for end users.

Types of Application Software

• Word Processing Software: This software enables users to create and edit documents. Eg MS-Word, Word Pad, Notepad etc

• Database Software: is a structured collection of data. Database software allows users to store and retrieve data from databases. Eg Oracle, MSAccess, etc.

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Other Types of Application Software

• Multimedia Software: They allow users to create and play audio and

video files. • Presentation Software:The software that is used to display information

in the form of a slide show is known as presentation software.

Other Types of Application Software

• Enterprise Software:It deals with the needs of organization processes and data

flow. • Educational Software:It has the capabilities of running tests and tracking

progress. It is often used in teaching and self-learning. • Simulation Software: Used to simulate physical or abstract systems, simulation

software finds applications in both, research and entertainment.

Other Types of Application Software

• Simulation Software:Used to simulate physical or abstract systems,

simulation software finds applications in both, research and entertainment.

• Content Access Software:It is used to access content without editing. Common

examples of content access software are web browsers and media players.

Other Types of Application Software

• Application Suites:An application suite is an important type of application

software. It consists of a group of applications combined to perform related functions.

• Information Worker Software:Individual projects within a department and individual

needs of creation and management of information are handled by information worker software.