History of the ComputerComputer Generation Classification of ComputerElements of the ComputerComputer NetworksInternet

Exam

Manual – Mechanical

Electromechanical

Electronic

devices powered by handand requires physical effortfrom the user

the first manual data processing device

mechanical calculating device first used around 2200 B.C. to add and subtract

developed in China in 12th century

invented by John Napier in 1617

a set of rods, made of bone or other material, each divided into nine spaces

contains the numbers of a column of the multiplication table

contrivance of Baron Napier, the inventor of logarithms, for facilitating the operations of multiplication and division

invented by William Oughtred in 17th century

a rule upon which are marked several graduated scales that may be moved relative to one another, so that certain calculations may be carried out

Depending on the scales so marked, these calculations may include multiplication, division, logarithmic and trigonometric functions

invented by Blaise Pascal in 1642

a mechanism to calculate with 8 figures and carrying of 10's , 100's, and 1000's

invented by Baron Gottfried Wilhelm Von Leibniz in 1674

utilizes the same techniques for addition and subtraction as Pascal’s device but could also perform multiplication and division & extract square roots

invented by Charles Babbage in 1822 designed to use two types of cards:1. operation cards to indicate the

specific functions to be performed

2. variable cards to specify the actual data

devices powered by an electric motor and uses relays and switches

invented by Herman Hollerith in 1880

a machine to tabulate census data more efficiently than by traditional hand methods

invented by Joseph Marie Jacquard in 1804

used punched cards to create patterns on fabric woven on a loom

the hole punches directed the threads up or down, thus producing the patterns

forerunner of the keypunch machine

invented by Howard Aiken in 1943

Mark I could perform the four basic arithmetic operations

could locate information stored in tabular form

also known as the Mark I digital computer

official name of the Mark I was Automatic Sequence Controlled Calculator

51 feet long, 8 feet high, and 2 feet thick

had 750,000 parts and 500 miles wire

weighed 5 tons

these are devices which use only electrical switches and circuitry instead of mechanical relays consists of circuit boards, transistors or silicon chips

invented by John Atanasoff in 1942

the first digital computer that used binary logic circuitry

and had regenerative memory

invented by Presper Eckert Jr. and John Mauchly in 1943 to 1946the first large-scale vacuum-tube computerconsisted of over 18,000 vacuum tubes and required the manual setting of switches to achieve desired resultscould perform 300 multiplications per second

a vast improvement upon ENIACMauchly and Eckert started working on it two years before ENIAC even went into operationTheir idea was to have the program for the computer stored inside the computer

the first full-scale computer with electronic stored programsMaurice V. Wilkes and his team at the university of Cambridge constructed the EDSACdesign was based on that of von Neumann

a computer milestone achieved by Dr. Presper Eckert and Dr. John Mauchly, the team that invented the ENIAC computer

the first commercially available computer

First Generation - 1940-1956: Vacuum Tubes

Second Generation - 1956-1963: Transistors

Third Generation - 1964-1971: Integrated Circuits

Fourth Generation - 1971-Present: Microprocessors

Fifth Generation - Present and Beyond: Artificial Intelligence

The first computers used vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire roomsvery expensive to operate use a great deal of electricity generated a lot of heat, which was often the cause of malfunctions

UNIVAC and ENIAC computers are examples of first-generation computing devicesUNIVAC was the first commercial computer delivered to a business client, the U.S. Census Bureau in 1951

Transistors: replaced vacuum tubes and ushered in the

second generation of computers invented in 1947 but did not see widespread use

in computers until the late 50s far superior to the vacuum tube, allowing

computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first-generation predecessors

2nd generation computers moved fromcryptic binary machine language to symbolic, or assembly, languages, which allowed programmers to specify instructions in wordsHigh-level programming languages were also being developed at this time (e.g. early versions of COBOL and FORTRAN. COBOL and FORTRAN - the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology

The development of the integrated circuit was the hallmark of the third generation of computers

Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.

first generation filled an entire room 4th generation could now fit in the palm of the handThe Intel 4004 chip, developed in 1971, located all the components of the computer - from the central processing unit and memory to input/output controls on a single chip

in 1981 IBM introduced its first computer for the home user

in 1984 Apple introduced the Macintosh Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors.

still in development, though there are some applications, such as voice recognition, that are being used todaythe use of parallel processing and superconductors is helping to make artificial intelligence a reality

1st

2nd

3rd

4th

5th

According to Purpose

General Purpose Computer

Special Purpose Computer

are designed to handle a variety of tasks. This is possible by utilizing the

stored-program concept. That is, a program or series of

instructions is prepared for each application and input to and temporarily stored in the

computer

also known as dedicated computers, are designed

around a specific application or type of

application

Special-Purpose Computer

According to Data Handled

Analog Computer Digital Computer Hybrid Computer

operates in a completely opposite way to the digital computer. all operations in an analog computer are performed in parallel. data are represented in an analog computer as voltages, a very compact but not necessarily robust form of storage (prone to noise corruption). A single capacitor (equivalent to the digital's computer use of a transistor) in an analog computer can represent one continuous variable

a machine that specialize in counting of items that are distinct from one another. e.g. text, integers

in which a digital computer is used to control and

organize inputs and outputs to and from attached analogue devices; for

instance analogue devices might be used to help

generate initial values for iterations

According to Capacity

Microcomputer

Minicomputer

Mainframe Computer

Super Computer

is generally synonymous with personal computer (PC), or a computer that depends on a

microprocessor. Microcomputers are designed

to be used by individuals, whether in the form of PCs, workstations or notebook

computers

a midsized computer. In size and power,

minicomputers lie between workstations

and mainframes

a very large and expensive computer capable of

supporting hundreds, or even thousands, of users simultaneously. The

distinction between small mainframes and

minicomputers is vague, depending really on how the

manufacturer wants to market its machines

the fastest type of computer. Supercomputers are very

expensive and are employed for specialized applications that require

immense amounts of mathematical calculations

a complete, working computer. The computer

system includes not only the computer, but also any software and peripheral

devices that are necessary to make the computer

function

It refers to the physical equipment or components of

an electronic data processing.

It gives information to the computer system so that it can perform its tasks

is similar to that of a standard typewriter, but it includes extra keys such as

function keys and the numeric pad

a device that controls the movement of the cursor or pointer on a

display screen; originally designed by

Xerox

which performs the same tasks as the mouse,

operates with a rotating metal ball inset in a small, boxlike device

and does not require a desktop

is a pressure-sensitive pad that is smaller,

more accurate, thinner, and less

expensive to build than the trackball

was designed initially to read penciled or

graphic information on exam answer sheets.

a device that can read text or illustrations printed on paper and translate the information into a form the computer can

use. A scanner works by digitizing an image -- dividing

it into a grid of boxes and representing each box with

either a zero or a one, depending on whether the box

is filled in

record images in digital form

are small mobile computers that accept input through a penlike

instrument called a stylus that you use to

write on the computer’s screen

device for converting sound waves into electrical energy

is a camera that is in some way connected

to the World Wide Web, or Internet

a small, touch-sensitive pad, usually a couple of inches square, which acts as an alternative to a mouse on some notebook/palmtop computers. It works by

sensing fingertip pressure

a manual control consisting of a vertical handle that can move freely in two directions; used as an

input device to computers or to devices controlled by computers

a type of display screen that has a touch-sensitive

transparent panel covering the screen. Instead of using a pointing device such as a mouse or light pen, you can

use your finger to point directly to objects on the

screen

An input device that utilizes a light-sensitive detector to select objects on a display

screen. A light pen is similar to a mouse, except that with a light pen you can

move the pointer and select objects on the display

screen by directly pointing to the objects with the pen

an input device that enables you to enter drawings and sketches into a

computer. A digitizing tablet consists of an electronic tablet and a cursor or pen. A cursor (also called a puck) is similar to a mouse, except

that it has a window with cross hairs for pinpoint placement, and it can

have as many as 16 buttons.

a pointing and drawing device shaped like a pen. You use a stylus

with a digitizing tablet or touch screen

is an input device used to scan a pattern of lines using optical sensing

techniques. The line attern is coded information about the item to which it relates

(e.g. the price and description of an item of

merchandise)

is a device, which responds to an input

quantity by generating a functionally related output usually in the

form of an electrical or optical signal

permits users to input printed or typewritten

documents with a scanner

involves the use of a special pen on a monitor surface, as

with a personal digital assistant

activated by user’s voice after voice has been programmed into the computer; currently

accepts limited number of vocal commands

these devices display information that has been held or generated within a

computer

peripheral that uses ink or toner to output

documents, images, and plain text files onto paper

display consisting of a device that takes signals

from a computer and displays them on a CRT

screen

a device that draws pictures on paper based on commands from a

computer. Plotters differ from printers in that they draw lines using a pen. As a result, they can produce continuous lines, whereas printers

can only simulate lines by printing a closely spaced series of dots.

Multicolor plotters use different-colored pens to draw different

colors.

a device used to produce sound

increase a message as temporary output that computer users hear

are reduced sized photographic reproductions

of printed information on film cards. The cards can be read using microfiche readers and printed using

microfiche printers

a piece of hardware that is used for both providing

information to the computer and receiving

information

the modem modulates the computer output to an acceptable signal for transmission and then demodulates the signal back for computer input

computer hardware that holds and spins a magnetic

or optical disk and reads and writes information on it

a rigid magnetic disk mounted permanently

in a drive unit

a direct-access disk, has information recorded

on it with a laser beam that burns pits into its

surface

the main part of a personal computer. The system

unit includes the chassis, microprocessor, main

memory, bus, and ports, but does not include the keyboard or monitor, or any peripheral devices

POWER SUPPLY

CPU

FAN

HEAT SINK

VIDEO CARD

MODEM

SOUND CARD

RIBBON CABLE

MOTHERBOARD

CD-ROM

HARD DRIVE

POWER CORDS

FLOPPY DRIVE

ZIP DRIVE

EXTRA CASE FAN

is the brains of the computer. Sometimes

referred to simply as the processor or central processor, the CPU is

where most calculations take place

supervises or monitors the functions performed by

the entire computer system according to

conditions set forth by the stored program

the part of a computer that performs all arithmetic computations, such as

addition and multiplication, and all comparison

operations. The ALU is one component of the CPU

(central processing unit).

is somewhat like an electronic filing cabinet capable of holding data

or instructions

ROM(Read Only)

RAM(Random Access)

contains the pre-programmed computer instructions such as the

Basic Input Output System (BIOS) and special data that the computer uses

throughout its processing.

is used to store the programs and data that

you will run.

the main circuit board of a microcomputer. The motherboard contains the

connectors for attaching additional boards. Typically, the motherboard

contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel

ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display

screen, keyboard, and disk drive. Collectively, all these chips that reside on the motherboard are known as the

motherboard's chipset

an interface on a computer to which you can connect a device. Personal

computers have various types of ports. Internally, there are several ports for connecting disk drives, display screens, and keyboards.

Externally, personal computers have ports for connecting modems,

printers, mice, and other peripheral devices

a connector in a computer into which an expansion card can be plugged. The

connector supplies power to the card and connects it to the data bus, address bus and control signals of the

motherboard

A collection of wires through which data is

transmitted from one part of a computer to another

computer instruction or data. Anything that can be stored

electronically is software

System Software Application

Software

consist of programs designed to facilitate the use of the computer by the user. Any

software required to support the production or execution of application

programs but which is not specific to any particular

application

a set of program designed to efficiently manage the

resources of the computer system.

is a system program that converts the English-like instructions used

by computer programmers into the

machine-readable code used by the hardware

perform such standard tasks as organizing and

maintaining data files, translating programs

written in various languages to a language

acceptable to the computer

is a type of program that solves specific user-oriented processing

problems

program accepts words typed into a computer and processes them to produce edited text

system allows you to use different typefaces, specify various margins

and justifications, and embed illustrations and graphs directly into the text. The most powerful

desktop publishing systems enable you to create illustrations, while less powerful systems let you

insert illustrations created by other programs

are computer programs that let people electronically create

and manipulate spreadsheets (tables of values arranged in

rows and columns with predefined to relationships to each other). Spreadsheets are

used for mathematical calculations such as accounts, budgets, statistics and so on

a set of programs is necessary to facilitate adding new data

as well as modifying and retrieving of existing data

within a database

interactive hardware or software played for

entertainment, challenge, or

educational purposes

Public Domain Software Freeware Shareware Commercial Software

Has no copy right Free to use or make copy of Can be copied, used in other programs,

or charged by anyone

Has a copyright Can only give away exact copies of the

software Can not be changed or used in another

program without the copyright holder’s permission

Has a copyright Allowed to use software paying for it

1. can be a demo2. can set an amount of time you can use the software3. Can trust that you will pay for it if you like the software

Has the most resistive copyright Have to buy the software before you can

use it. Can usually make one copy of the

software as a backup copy Can not copy, look at the program’s code,

change, or use the software in another program.

1. MANAGEMENTused in school management such as budget, inventory, student records, etc.

2. LEARNING INSTRUCTIONteacher-centered instructionstudent-centered learning

3. EDUCATIONAL RESEARCHfor gathering and processing

a group of computers and other devices connected

together.

is a group of computers and associated devices that share a common

communications line and typically share the

resources of a single processor or server within a small geographic area (for example, within an office

building)

a data network designed for a town or city. (MAN) A data network intended to serve an area the size of a large city. Such networks are being implemented by

innovative techniques, such as running optical fibre through subway

tunnels.

are built to provide communication solutions for organizations or people who

need to exchange digital information between two

distant places (in one country or in two different

countries)

the computers are within a limited geographic

area, such as a campus or military base

a network contained within a user's home that

connects a person's digital devices

Networks Topology

All devices are connected to a central cable, called the bus or backbone. Bus networks are relatively

inexpensive and easy to install for small networks.

Ethernet systems use a bus topology

All devices are connected to one another in the shape of a closed

loop, so that each device is connected directly to two other devices, one on either side of it.

Ring topologies are relatively expensive and difficult to install,

but they offer high bandwidth and can span large distances

All devices are connected to a central hub. Star

networks are relatively easy to install and

manage, but bottlenecks can occur because all data must pass through the hub

A tree topology combines characteristics of linear

bus and star topologies. It consists of groups of star-configured workstations

connected to a linear bus backbone cable

Types of Cables Used in Networks

 Unshielded Twisted Pair (UTP) Cable

 Shielded Twisted Pair (STP) Cable

Microwave  Coaxial Cable  Fiber Optic Cable

Unshielded twisted pair (UTP) is the most popular and is generally the best option for school networks. The quality of UTP may vary from telephone-grade wire to extremely high-speed cable. The cable has four pairs of wires inside the jacket.

Each pair is twisted with a different number of twists per inch to help

eliminate interference from adjacent pairs and other electrical devices. The

tighter the twisting, the higher the supported transmission rate and the

greater the cost per foot.

A disadvantage of UTP is that it may be susceptible to radio and electrical

frequency interference. Shielded twisted pair (STP) is suitable for

environments with electrical interference; however, the extra shielding can using Token Ring topology. make the cables quite

bulky. Shielded twisted pair is often used on networks

are very high-frequency radio signals

that are transmitted through open space.

Coaxial cabling has a single copper conductor at its center. A plastic layer provides insulation between the center

conductor and a braided metal shield. The metal shield helps to block any outside

interference from fluorescent lights, motors, and other computers. Although coaxial cabling is difficult to install, it is highly

resistant to signal interference. In addition, it can support greater cable lengths between

network devices than twisted pair cable.

Fiber optic cable has the ability to transmit signals over much longer distances than coaxial and twisted pair. It also has the capability to carry information at vastly greater speeds. This capacity broadens communication possibilities to include

services such as video conferencing and interactive services. The cost of fiber optic cabling is comparable to copper cabling; however, it is more difficult to install and

modify.

provide a special form of microwave transmission. It requires earth stations, or “dishes,” that transmit

and receive signals to and from the orbited

satellite

A wide collection of computer networks

The software program you use to access the World Wide Web

Uses the text in a web site to index so that search engine users can find

it by typing it by selecting the appropriate category.

Uses human editors to place the site into a hierarchy or outline of topics so that users can find it by selecting

the appropriate category.

A method of naming documents or places on the internet

it refers to all of the publicly accessible web sites in the world

in an electronic message sent from one computer to another.