History of the Computer Computer Generation Classification of Computer Elements of the Computer Computer Networks Internet Exam
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.