It (harware and Software)

HARDWARE

The computer system is made up of 2 parts; the hardware and the software. Hardware is the name given to all the devices that make up the computer system. These are components of the computer that can be physically handled.

Hardware are divided into input devices, central processing unit, backing storage and output devices.

Input devices

Input devices are used to get data into the computer. Examples: keyboard, mouse, joystick, light pen, optical scanner and microphone.

The central processing unit

The Central Processing Unit (CPU) of a computer is the main processor which operates the computer - I.e. it carries out the instructions of the program being run.

The CPU has three main parts:

The A.L.U. (Arithmetic and Logic Unit) which performs all the calculations.

The Control Unit - which controls the flow of data round the computer by sending out control signals.

Memory - which is used to store data.

The backing storage

Storage hardware provides permanent storage of information and programs for retrieval by the computer. The two main types of storage devices are disk drives and memory.

Disk drives

Hard disk drives store information in magnetic particles set in in a disk. Usually a permanent part of the computer, hard disk drives can store large amounts of information and retrieve that information very quickly.

Floppy disk drives also store information in magnetic particles set in in removable disks that may be floppy or rigid. Floppy disks store less information than a hard disk drive and retrieve the information at a much slower rate.

Compact disc drives store information on pits burned into the surface of a disc of reflective material. CD-ROMs can store about as much information as a hard drive but have a slower rate of information retrieval. A digital video disc (DVD) looks and works like a CD-ROM and can store more than 15 times as much information.

Memory

Memory refers to the computer chips that store information for quick retrieval by the CPU. Random access memory (RAM) is used to store the information and instructions that operate the computer's programs.

Read-only memory (ROM) contains critical information and software that must be permanently available for computer operation, such as the operating system that directs the computer's actions from start up to shut down.

Output devices

Output devices are used to provide production in the form of printouts, screen displays and sounds. Examples: monitor (VDU), liquid crystal display (LCD), printers, graph plotters and speakers.

PICTURE OF A COMPUTER



DIAGRAM OF COMPUTER SET-UP



Hardware that I used to produce my coursework

Keyboard

Mouse

Monitor

Printer

Hard disks

The LAN network

Floppy disk

A network consists of a number of computers linked together.

A LAN (Local Are Network) - the computers are on the same site and linked by cables.

SOFTWARE

Software is the general name given to all the programs that can be run on computer hardware. Software as a whole can be divided into a number of categories based on the types of work done by programs. The two main software categories are operating systems (system software) and application software.

Two additional categories that are neither system nor application software, although they contain elements of both, are network software and language software.

Network software enables groups of computers to communicate and language software provides programmers with the tools they need to write programs.

OPERATING SYSTEM

The Operating system is the most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers.

In any computer, the operating system:

controls the backing store and peripherals such as disk units and printers

controls the loading and running of programs

organises the use of memory between programs

organises processing time between programs and users

organises priorities between program and users

maintains security and access rights of users

deals with errors and user instructions

Operating systems are classified as:

Multi - user

A multi-user (or multi-access) system is one where a number of users work with terminals on-line to a central computer. The central processor deals with users in turn; clearly the more users, the slower the response time.