Basic Computer Concepts

What is Computer?

Computer is the term that was originally given to person who performed numerical

calculations using mechanical calculators such as the slide rule and abacus. Nowadays

a computer is considered to be an electronic device that allows inputting data and

having it stored, processed, or otherwise manipulated quickly and efficiently.

Computers help make jobs that used to be complicated much simpler. For example, a

user can easily write letters in a word processor and edit any portion of the letter

anytime, spell check the letter, and move text from another document into the letter,

etc. This is just one of the hundreds of different things a computer is capable of doing.

The first computer was called the ENIAC, which was built during World War II.

Computers first utilized vacuum tubes and were very large (sometimes room size) and

only found in businesses, Universities, or governments. Later, computers began

utilizing transistors as well as smaller and cheaper parts that allowed the common

person to own their own computer.

Basic Computer Concepts

i) Computer Architecture

It is the overall design and setup of the computer. This includes where each of the

connections and parts of the computer are to be placed, how each of components

operate with each other, dimensions, etc.

Today, most computers are often comprised with some or all of the below

components.

Bay Case or Chassis CD-ROM, CD-R, and/or CD-RW CPU DVD Floppy disk drive Hard disk drive Keyboard Memory Microphone Monitor, LCD, or other display

device Motherboard Mouse Printer Sound card Speakers Video card

Input devices

An input device is a hardware device that sends information into the CPU. Without

any input devices a computer would simply be a display device and not allow users to

interact with it, much like a TV. Some of the computer input devices are as follows

Digital camera

Digital camera is a type of camera that

records and stores pictures or videos. The

main feature of digital camera is the

ability to take dozens, sometimes

hundreds of different pictures.

Sadiq Merchant; Hamdard University; HIESS; B.Ed-Weekend (2007-2009); Semester: Two 1


Joystick

Joystick is an input which allows an

individual to easily navigate an object in

a game such as navigating a plane in a

flight simulator.

Keyboard

One of the main input devices used on a

computer, a PC's keyboard looks very

similar to the keyboards of electric

typewriters, with some additional keys.

Microphone

It is the hardware device that allows

computer users to input audio into their

computers.

Mouse

It is an input device that allows an

individual to have the ability to perform

various functions on computer such as

opening a program or file.

Scanner

It is a hardware input device that allows a

user to take an image and/or text and

convert it into a digital file, allowing the

computer to read and/or display the

scanned object.



Web cam

It is a camera which is connected to a

computer to allow a person to view other

people, places, and even events.

CPU and Storage Devices

CPU; also known as a processor or microprocessor; is short for Central Processing

Unit. It is responsible for handling all instructions and calculation it receives from

other hardware components in the computer and software programs running on the

computer.

The first CPU was manufactured by

INTEL in 1974. The adjacent picture is

on of the latest processors.

Motherboard

It is a circuit that is the foundation of a

computer and allows the CPU, RAM, and

all other computer hardware components

to function with each other.

Modem

It is a device that enables a computer to

transmit and receive information over

telephone lines.



A storage device is a hardware device designed to store information. There are two

types of storage devices used in computers; a 'primary storage' device and a

'secondary storage' device. A primary storage device is the storage location that holds

memory for short periods of times. For example, computer RAM, etc. A secondary

storage device is the medium that holds information until it is deleted or overwritten.

For example, hard disks drive, etc. Here are few examples of storage devices:

RAM

It is short for Random Access Memory

which is the main memory of the system

within a computer. RAM requires power;

if power is lost, all data is also lost.

Diskette

It can record data as magnetized spots on

tracks on its surface. Diskettes became

popular along with the personal computer

mainly to transport data.

Hard Drive

It is a rigid circular disk located inside a

computer. The term hard disk is often

used as an abbreviation to hard disk

drive.

Removable hard drive

It is a hard drive that can be placed within

a plastic or metal cartridge that enables it

to be removed easily and placed into

other computers with similar bays.



Zip drive

It is a data storage device similar to the

Standard 1.44" floppy drive having

capability to hold upto 100 MB or 250

MB of data. Because they were cheap,

they became very popular in late 1990s.

CD-R, CD-RW

CD-R is short for CD-Recordable and is

a type of writable disc capable of having

information written on it only once

CD-R/W is a drive and/or media that is

capable of being written many times.

Output Devices

These devices display and generate information that has been held or generated within

a computer. Some examples are shown below.

Monitor

It is a video display screen and the hard

shell that holds it. It is used to visually

interface with the computer and are

similar in appearance to a television.

Printer

It is an external hardware device

responsible for generating a hard copy of

data. It is commonly used to print text,

images, photos, etc.



Speaker

It is a hardware device connected to a

computer's sound card that outputs

sounds generated by the card.

Projector

It is a device that enables an image, such

as a computer screen, to be projected onto

a flat surface. These devices are

commonly used for presentations.

Plotter

It is a device that draws pictures on paper

based on commands from a computer

using a pen. Multicolor plotters use

different-colored pens to draw different

colors.

ii) Introduction to Computer Software and Hardware

Software

Softwares are the computer programs containing instructions that cause the computer

to do work. Software consists of a set of instructions a computer uses to manipulate

data, such as a word-processing program or a video game. Software also governs how

the hardware is utilized; for example, how information is retrieved from a storage

device.

Software as a whole can be divided into a number of categories based on the types of

work done by programs. The two primary software categories are as follows:

I. Operating systems (system software) control the working of the computer.

These softwares handle essential, but often invisible, chores as maintaining

disk files and managing the screen, etc.

II. Application software addresses the multitude of tasks for which people use

computers. Application software performs tasks like word processing,

database management, and the like.



Two additional categories that are neither system nor application software, although

they contain elements of both, are as follows;

III. Network softwares enable groups of computers to communicate, etc

IV. Language softwares provide programmers with the tools they need to write

programs.

In addition to the above task-based categories, several types of software are described

based on their method of distribution. These include the Following

V. Packaged software; developed and sold primarily through retail outlets

VI. Freeware and public-domain software; made available without cost by its

developer

VII. Shareware; usually carries a small fee for those who like the program

Hardware:

Hardware consists of the components that can be physically handled. The functions of

these components can be typically divided into three main categories: input, output,

and storage. Components in these categories connect to microprocessors, specifically,

the computer’s central processing unit (CPU), the electronic circuitry that provides the

computational ability and control of the computer, via wires or circuitry called a bus.

Three kinds of hardware are explained as follows:

I. Input Hardware consists of external devices; components outside of the

computer’s CPU providing information and instructions to the computer.

These include light pen, mouse joystick, keyboard, Touch-screen displays,

optical scanner, microphone, modem, network interface card, etc.

II. Output Hardware consists of internal and external devices that transfer

information from the computer’s CPU to the computer user. These include

Display units likes a video screen with a cathode-ray tube (CRT) or a video

screen with a liquid crystal display (LCD), Printers, speakers or headphones,

projectors, etc.

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. There are several types of disk drives: hard, floppy, magneto-optical,

magnetic tape, Compact disc drives (CD-ROM, CD-R, CD-RW, DVDs, DVD-R, and

DVD-RW), etc.

Types of Computer

Computers are mainly categorized into the following types:



Digital Computer Analog computer Hybrid Computer

Digital Computer:

It is the type of computer that stores data in terms of digits (numbers) and proceeds in

discrete steps from one state to the next. In digital computers, letters, words and

whole texts are represented digitally. It performs calculations and logical operations

with quantities represented as digits, usually in the binary number system. Digital

computers can be built to take the solution of equations to almost unlimited precision,

but quite slowly compared to analog computers. For many real-time operations, the

speed of such digital calculations is too slow to be of much use.

Analog Computer:

It is the type of computer that represents data in terms of physical measures or

quantities and proceeds along a continuum constituted by its components. Analog

computers are especially suited for the solution of complex non-linear equations and

for the simulation of multi-dimensional, parallel and continuous processes. There is

no restriction on the physical processes analog computers may utilize. In general,

analog computers are extraordinarily fast, since they can solve most complex

equations at the rate at which a signal traverses the circuit, which is generally an

appreciable fraction of the speed of light. On the other hand, the precision of analog

computers is not good; they are limited to three, or at most, four digits of precision.

Compared with digital computers, the programming of analog computers is time

consuming and limited in scope.

Hybrid Computer:

Hybrid computers are computers that comprise features of analog computers and

digital computers. The digital component normally serves as the controller and

provides logical operations, while the analog component normally serves as a solver

of differential equations. Hybrid computers can be used to obtain a very good but

relatively imprecise value, using an analog computer front-end, which is then fed into

a digital computer process to achieve the final desired degree of precision.



Source:

http://www.computerhope.com/jargon/i/inputdev.htm

http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading05.htm

http://encarta.msn.com


http://encarta.msn.com/

http://homepage.cs.uri.edu/faculty/wolfe/book/Readings/Reading05.htm

http://www.computerhope.com/jargon/i/inputdev.htm

Basic Computer Concepts

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