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Introduction to Computer

Computer Fundamentals

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HOW DO COMPUTERS

WORK?

Computers contain thousands of tiny electricalswitches located in microchip.

The Central Processing Unit, CPU is the brain ofthe computer and it has a tiny microprocessor(about 1/4-inch square) and is programmed at thefactory to be able to look at any of the 8-bitpanels (or bytes) and figure out what it is to dowith them.

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WHAT MAKES COMPUTERBRAIN

In today's computer marketplace there are twomain companies that manufacture microprocessor

CPUs; Intel Corporation and MotorolaCorporation. Intel makes CPUs for IBM andIBM-compatible computers.

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ARE ALL COMPUTERS THE SAME ?

In the 1980's most computers were designed with the

8-bit architecture. This configuration is obsolete todayThese can only handle many simple office tasks suchas word-processing, accounting, filing.

To extend the capabilities of personal computers,engineers designed the newer 16-bit architecture wichstill has limitations

For multimedia applications, even more capabilitiesare required. Today's minimum standard for amultimedia computer is a 32-bit design. This caneffectively work with Computer Aided Design andDrafting (CADD)

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WHAT ARE FLOPPY DISKS AND HARDDISKS ? A floppy disk is a circular piece of very thin plasticcoated

with microscopic-sized iron particles. It is used to storecomputer information much like a digital audio tape storesmusic and songs. Like an audio tape, a floppy disk can beerased and reused over and over again.

Floppy disks are 3.5"in diameter.

A typical floppy disk can store 1.44 MBof information.

A hard disk drive contains circular platters of highlypol ished steelwhich can also store computer informationand can be erased and reused.

A hard disk has its steel disks permanently containedinside a sealed cabinet rather than being inserted andremoved by the computer user.Hard disks can store much more information than floppy

disks. A typical hard disk today can store 6,000 MB(6Gig) to 75,000 MB (7.5Gig)of computer information.

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OTHER STORAGE DEVICES Fortunately, several new products have arrived on the

market for storing greater amounts of information. One

popular item is the ZIP drive (from IomegaCorporation). This drive uses a disk or cartridge justslightly larger than a 3.5 inch floppy but capable ofstoring 100 MBof data! These devices can be installedinside the computer case or connected outside the

computer via a special cable. Another useful storage device is the CD or Compact

Disc. The new CD drives can record and storeapproximately 650 MBof data.

All computers today come with CD-ROM drives.These drives cannot be used for recording -- they canonly be used to retrieve the data that's pre-recorded onthem by the manufacturer. The term CD-ROM, which

stands for Compact Disc Read Only Memory, is rathermisleading.

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WHAT IS MEANT BY THE TERMWINDOWS

Many people used to fear using computers becausethey didn't understand the cryptic language that peopletyped at the keyboard to get their computers to dosomething.

Therefore a company called Microsoft Corporation,designed a mouse-driven interface called Windows.

With Windows you point by using a mouse which is asmall device connected with a wire to the computer.

Microsoft first released Windows 3.11 followed by

Windows 95, 98, 2000 and ME

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WHAT IS DISK OPERATINGSYSTEMS (DOS)

As mentioned at the beginning of the previoussection, only a PARTof the Operating System of

a computer is contained in the ROM chip. Thegreater majority comes from your hard drive andis loaded into RAM every time you turn the

computer on. This portion of the OperatingSystem is called DOS, meaning Disk-basedOperating System.

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OTHER HARDWARES1. Printers

In the last five years, printer technology hasadvanced significantly and prices have fallendramatically.

We have Black & White Laser Printers and Colour

Inkjet Printers

2. Modems

The modem is a device that allows a computer to beconnected to your telephone line. Modems may beinstalled inside the computer's case or connected tothe computer's exterior serial port.Once connected, you can send or receive faxes and

electronic mailor even the Internet.

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3. Scanners

A scanner is used to transfer text or photos(illustrations) to the computer.

A flatbedscanner resembles a small photocopier.You insert the original document face down ontoa glass plate. A special software program controlsthe scanner. Once the document is scanned, it can

sent to the printer or faxed via the modem.

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WHAT IS NETWORKING ?

A network refers to two or more computers that areconnected so they can share hardware andsoftware. For example, a home-based businessmight have two computers and only one laserprinter. By connecting the two computers with

special network cables, and implementing somebasic networking software, both computers couldaccess the laser printer.

Networked computers require hardware callednetwork interface cards

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Offices and schools often have all theircomputers networked to each other. This is

commonly called a Local Area Network orLAN.

Wide Area Network, or WAN, consists ofcomputers that are connected over a widegeographic area, such as a city or a country.In this setup, information is transmitted viatelephone lines, microwaves or satellites.