A
1. Computer virus
Is a malware program that, when executed,
replicated by inserting copies of itself(possibly modified) into other computer
programs, data files, or the boot sector of the hard drive; when this
replication succeeds, the affected areas are then said to be infected. Virus
perform some harmful activities like stealing hard disc space or CPU time,
corrupting data, displaying political harmonious messages on the user’s screen,
spamming their contacts, logging their keystrokes, or even rendering the
computer useless
2.
Types of computer virus There are various types of computer
viruses, classified in terms of techniques, origin, the type of files affected,
damage, OS or platform attacked, as well as the places they hide. 3It’s
relatively hard to answer how many different types of computer viruses there
are but below cover the main core concepts of the common types.
Macro
viruses
These viruses infected
the file created using some applications or program that contains macros such
as dos, apps, xls, and mdb. They automatically infect the files with macros and
templates and documents that are contained in the files. They hide in documents
shared through e-mail and networks. They include Relax, bablas, Melissa. A,
097M/Y2K.
Memory-Resident Viruses
They usually fix themselves inside the computer memory. They get activated every time the OS runs and end up infecting other opened files. They hide in RAM. These include CMJ, Meve, randex, mrklunky.
They usually fix themselves inside the computer memory. They get activated every time the OS runs and end up infecting other opened files. They hide in RAM. These include CMJ, Meve, randex, mrklunky.
Overwrite
Viruses
These types of viruses
delete any information in a file they infect, leaving them partially or
completely useless once they are infected. Once in the computer, they replace
all the files content but the file size doesn’t change. They includes Trj,
Reboot, way, trivial, 88, D.
Direct
Action Viruses
These viruses mainly
replicate or take action once they are executed. When a certain condition is
met, the viruses will act by infecting the files in the directing or the folder
specified in the AUTOEXEC. BAT. The viruses are generally found in the hard
disks root directory, but they keep on changing location. These includes Vienna
virus.
Directory
Virus
Also known as cluster
virus or file system virus. They infect the computers directory by changing the
path indicating file location. They are usually located in the disk but affect
the entire directory. They includes dir-2 virus.
Web
Scripting Virus
Most web pages include
some complex codes in order to create an interactive and interesting content.
Such a code is often exploited to cause certain undesirable action. They mostly
originate from the infected web pages or browsers. This includes JS,
Fortnight-a virus that spreads via malicious emails.
Multipartite
virus
These types of virus
spread in any different ways. Their actions vary depending on the OS installed
and presence of certain files. They tend to hide in the computer’s memory but
do not infect the hard disk. They include flop invader tequila.
FAT
Viruses
These lardy viruses
attack the file allocation table (FAT) which is the disc part used to store
every information about the available space, location of files, unusable space
etc. These include the link virus.
Companion
Viruses
These types of viruses
infect the files just like the direct action and the resident types. Once
inside the computer, they “accompany” other existing files. These are like
Asimor 1539, stator and terrax. 1069.
Macro
Virus
This virus affects
files created using particular programs or application containing macros. The
mini programs increase their ability to automate some operations, in which case
they would be performed as single actions. The user would therefore be saved
the trouble of executing them singularly.
3.
Spyware.
Is a type of malware
that is installed on a computer without the knowledge of the owner in order to
collect the owner’s private information. Spyware is often hidden from the user
in order to gather information about internet interaction, keystrokes (also
known as key logging), passwords, and other valuable data. Spyware can also
negatively affect a computer’s performance by installing additional software,
redirecting web browser searches, changing computer setting, reducing
connection speed.
4.
Malware.
Is an abbreviated term
meaning “Malicious Software”. This is software that is specifically designed to
gain access or damage a computer without the knowledge of the owner. These are
various types of malware including Spyware, key loggers, true viruses, worm, or
any type of malicious code that infiltrates a computer. Generally, software is
considered malware based on the intent of the creator rather than actual
features.
5.
Trojan horse.
The term comes from the
Greek mythology about the Trojan War, as told in the Aeneid by Virgil and
mentioned in the odyssey by Homer. According to legend, the Greek presented the
citizen of Troy with a large wooden horse in which they hard secrete hidden
their warrior. During the night, the warrior emerged from the wooden horse and
overrun the city.
Therefore, Trojan horse
is a program in which malicious or harmful code contained inside apparently
harmless programming or data in such a way that it can get control and do its
chosen allocation table on your hard disk. In one celebrated case, a Trojan
horse was a program that was supposed to find and destroy computer viruses. A
Trojan horse may be widely distributed as part of computer viruses.
(B) Characteristics of computer viruses
Parasitic
virus (dependent), Virus program embedded into the host
program, depends on the survival of the host program’s implementation, which is
a parasitic virus. Virus program to invade the host program, the general
procedures of the host to be modified, once the host program execution, and the
virus program is activated, which can self-replicate and reproduce.
Deceptive
computer virus, computer viruses secretive,
unresponsive to their computer, often to the fact that the virus causing the
error as accepted, so it is easy to be successful.
Persistent
virus, even after the virus program has been detected,
data and programs as well as the operating system are very difficult to
restore. Especially in network operating conditions, because the virus program
from a copy of infection spread through the network repeatedly, making the
virus removal process is very complex.
Targeted
virus ,
computer viruses are specific for a particular computer and operating system.
For example, for the 1BM PC and compatible machines, the company targeted Apple
Macintosh, and for the IBM PC, the DOS operating system.
Attack
of the initiative, virus attack the system is active, not
to man’s will transfer. In other words, from a certain extent, the computer
system regardless of how strict conservation measures taken can not completely
rule out the virus attacks the system, while the protection is at best a means
to prevent it.
Viruses
and unauthorized, virus unauthorized execution. The
normal procedure is invoked by the user, then the allocation of the resources
by the system to complete task assigned by the user. The purpose of the user is
visible and transparent.
They
are destructive, All computer virus are a kind of
executable program, and this is bound to run another executable program, so the
system is concerned, all computer viruses are a common hazard exists, that
reduce the efficiency of computer systems, taking up system resources their
invasion of the system depending on the virus program.
Enforceability,
computer virus and other legal procedures, is a executable program, but it is
not a complete program, but the parasite in other executable programs. The
virus is running, and the due process right to fight for control of the system.
Computer viruses only when it can be run in the computer only when such
activity is contagious and destructive. That is control of the computer CPU is
the key issue.
Virus
derivative, this feature provides for some busybody brings a
new virus to create a shortcut. Analysis of the structure of known computer
viruses, the damage spread partly reflected the designer’s design thinking and
design purposes.
The
characteristics of computer worms
·
Replicate itself with ease.
·
The kicker though is that they can do so
without human assistance.
·
They can create hundreds of copies of
themselves in computer networks.
·
Target vulnerable system.
Characteristics
of Trojan horse.
·
Targets the vulnerable system.
·
They let things into the computer.
·
Need to be executed by the user in order
to infect files.
·
Are never touched or even seen by the
user.
·
They allow a cracker to gain access to
remote computer.
·
They record what the user types and send
it out in some way, most likely to the email address or directly to the
computer of the creator.
·
May format the hard drive or make the
computer unusable in some other way.
The
similarities between computer viruses and computer worms.
·
Both are generally malicious software.
·
Both attacks computer system.
·
Both are viruses.
The
difference between computer viruses and computer worms.
·
All worms are viruses, but not all
viruses are worm.
·
Worms targets vulnerable systems, but
virus attaches itself to other software.
·
Worms do not require any interaction,
but virus requires user interaction.
·
Worms propagate quickly, but virus
propagates slowly.
·
Worms can attack any unlatched machine
that is on the network, but virus primary attack workstations, as user must be
as the console machine to initiate the virus infection.
·
Worms are hacker’s best friend, but
viruses are not the primary mechanism of attack of hackers.
·
Worms cannot easily detected by antivirus
software, but virus can be caught via the user of antivirus software.
(C) Ways on how computer viruses are spread.
1. Email attachments. The world became familiar with the phenomena of email attachments carrying viruses thanks to Microsoft’s Outlook Express automatically opening every attachment to every email you received a few years back. Now that email clients no longer do this, the infection rate from email attachments is significantly lower, but it can still be a common problem. The golden rule is that if you don’t know what an attachment is, don’t open it. To this day, many email users never open attachments, no matter what. You don’t have to take such drastic steps to protect yourself, however; simply use common sense when opening attachments in your email.
2. Rogue Websites. It is depressing to know that you may become infected with spyware or a virus by doing nothing more than simply visiting a website, but it is true. Many adult websites, gambling websites and other less than trustworthy websites will attempt to automatically access your computer when you visit them. They often install adware bugs that will cause a flurry of pop ups to appear on your screen. This adware will often allow for other programs with even more nefarious purposes to be installed and before you know it, your computer will be swamped. To stop these rogue websites, adjust the settings on your antivirus software and firewall so that no outside connections can be made and no programs can be installed without your express permission.
3. Networks. If your computer is connected to a home network or if your work computer is part of a larger network, you may find yourself with an infection through no fault of your own. Someone else on the network downloaded a bug by accident, and within minutes, the entire network could be infected. There isn’t much you can do to stop these kinds of infections, short of having your network administrator ensure that everyone’s antivirus software is up to date so that the invading bug can be removed as quickly as possible.
4. Infected Boot disks. Now that hard drives are obscenely large, the overwhelming percentage of us don’t bother to use boot disks anymore, but a virus can still be spread if an infected disk is in your hard drive and you attempt to restart. When you start your computer, your machine will always check your drives to see if a disk with boot information is present. If one is, your computer will likely automatically attempt to boot from the disk and not from your drive. If a virus is present, it will often be activated and you will become infected. Always know the origin of any disk you put into your drive.
5. Phishing Schemes. Learning how computer viruses spread is important to keep yourself, and your personal information, safe online. Phishing schemes are one of the chief ways in which people end up with their identity stolen and a computer fill of viruses. A phishing scheme starts when you receive an email from a website claiming to be your bank or Credit Card Company. You are asked to click a link and log in, but the truth is that you’ve just given away all of your personal information. Often times, when you visit these sites, spyware, adware and viruses are automatically installed on your computer (see Rogue Websites, above). Your lender or credit card will often send out a real notice that lets you know that a phishing scheme is going around.
6. Infected Software. One of the great things about the Internet is how many free games and programs there are out there, but these free programs often come at a price. Too many rogue websites intentionally infect their freeware (like Kazaa) with Trojan viruses so that you unknowingly infect your computer every time you download a free game or piece of software. The key here is to only download freeware or shareware from a trusted source like CNet that always ensures your safety.
7. Hackers. The Internet today is a much more law abiding place than it was ten years ago. Not only did most people not have antivirus protection and firewalls that could stop incoming attacks, most people didn’t even know what they were. Today, people understand the value of good online protection, but hackers can still pose a problem if you allow your protection software to lapse. The best way to beat hackers is to ensure that you have a firewall and up to date antivirus software.
8. Instant Messaging. It is difficult to find a computer in this day and age that doesn’t have at least one instant messaging service installed on it. Unfortunately, these programs are often targets of hackers who see an easy way to trick people into clicking links that lead them to rogue websites. Common sense can keep you out of trouble, however. Only chat with people you know and never follow links to sites that you don’t recognize. You should easily be able to keep Internet worms, viruses and other bugs at bay.
9. Fake Anti Virus Software. This is one of the most frustrating ways to become infected with a virus or worm. There are dozens of antivirus and anti spyware programs you can download for free on the Internet and a surprising number of them actually do exactly the opposite of what they claim. The product websites make outrageous claims that their product can protect you from a whole range of threats, when, in reality, their product will only make things a thousand times worse. Only download antivirus programs from trusted sites or from websites that you know are completely legit.
10. From Mobile Devices. A recent story in the newspaper should serve as a wakeup call for anyone who is getting ready to plug in a mobile device into their computer for the first time. A family purchased a digital picture frame from a local store and when they attempted to install the software that came with it, they inadvertently infected their computer with a virus. There really is no way to stop such an infection from happening, since we all buy peripherals that work with our computer, but we can ensure that we have the tools ready to go if an infection should happen. Keep your antivirus software up to date at all times and you should be able to wrestle control back from any Internet bug.
11. Friends and Relatives. Often times, we are sent viruses through our email from people that we know and trust. The social networking site Facebook has had to battle this very problem when their serves get a bug and automatically send out emails to everyone on the system that are infected. Often times, these emails are extremely generic sounding and come with suspicious attachments, but people often open them anyway since they have come from a friend or from a site they trust, like Facebook. Remember, if you get an attachment with an .exe extension or a dll, don’t ever open it.
Ways
on how computer viruses are prevented.
·
Keep a regular backup of your important
files (on floppy, zip disk, write able CD, tape, another hard disk etc).
·
Be aware that most current virus arrives
as e-mail attachments. Be very suspicious of any attachment that has any of the
following file extensions. Exe, vbs, scr, vbe, bat, com, shs, cpl, dll, ocox
pif, drv, Ink, bin, sys, eml, nws.
·
Update your virus scan program now if
you haven’t done it for over a month.
·
Update the virus definition files
regularly, typically once a week but no fewer than once a month.
·
To be very cautious about opening email
attachments.
·
Clean your virus.
2(A).
Computer crimes, is the crime that
is committed with a computer over a network. OR refer to the use of information
technology for illegal purposes or for unauthorized access of a computer system
where the intent is to damage, delete or alter the data present in the computer.
Even identity thefts, misusing devices or electronic frauds are considered to
be computer crimes.
Types of computer crimes.
Hacking.
The act of defeating the security capabilities of a computer system in order to
obtain an illegal access to the information stored on the computer system is
called hacking. Another highly dangerous computer crime is the hacking of IP
addresses in order to transact with a false identity, thus remaining anonymous
while carrying out the criminal activities.
Phishing.
Phishing is the act of attempting to acquire sensitive information like
username, password and credit card details by disguising as a trustworthy
source. Phishing is carried out through emails or by luring the user to enter
personal information through fake websites. Criminals often use websites that
have a look and feel of some popular website, which makes the users feel safe
to enter their detail there.
Computer
viruses. There are actually computer programs that are
capable of replicating themselves and harming computer systems present in a
network. These viruses work without the knowledge of the users and spread from
one computer to another through the network. Internet or removable devices like
CDs and USB drives. Writing computer virus is a criminal activity and is
punishable by law.
Identity
theft. This one of the most serious frauds in today’s
world. It involves stealing money and getting benefits by using an identity of
another person. This also includes the use of someone else’s credit card
details to purchase goods and services. It has been seen that blackmail and
terrorism often employ identity theft.
(B)
Hacker. Is the term that first started being used in the
1960’s that described programmer or someone who hacked out computer
code. Later the term evolved to an individual who had an advanced understanding
of computers, networking, programming, or hardware, but did not have any
malicious intent.
Hackers referred
to as a black hat or criminal kicker, which describes any individual who
illegal breaks into computer system to damage or steal information.
Cracker.
A cracker (also known as a black hat hacker) is an individual with extensive
computer knowledge whose purpose is to breach or bypass internet security or
gain access to software without paying royalties. The general view is that,
while hackers build things, cracker break things. Cracker is the name given to
hackers who break into computers for criminal gain; whereas, hackers can also
be internet security experts hired to find vulnerabilities in systems.
Crackers can also refer to those who
reverse engineer software and modify it for their own amusement. The most
common way crackers gain access to networks or system is through social
engineering, whereby the cracker contacts employees at a company and tricks
them into divulging passwords and other information that allow a cracker to
gain access.
(C).
Cyber bullying. Is bullying that
takes place using electronic technology. Electronic technology includes devices
equipment such as cell phones, computers, and tablets as well as communication
tools including social media sites, text messages, chat, and websites. Examples
of syberbullying include mean messages or emails, rumors sent by email or
posted on social networking sites, and embarrassing pictures, videos, websites,
or fake profiles.
Cyber
spoofing. Is an attack or spam when the attacker disguises a
fake information source to appear as legitimate. Spoofing is one of the common
forms of cyber crime. Typically the attacker creates the proof spam with the
intention of illegitimately gathering information from the user.
Denial of
service (DOS).
Is an incident in which a user or organization is deprived of the services of a
resource they would normally expect to have. In a distributed denial of
service, large numbers of the compromised systems (sometimes called a botnet)
attack a single target. .Common forms of denial of service
attacks are:
Buffer Overflow Attacks
The
most common kind of DoS attack is simply to send more traffic to a network
address than the programmers who planned its data buffers anticipated someone
might send. The attacker may be aware that the target system has a weakness
that can be exploited or the attacker may simply try the attack in case it might
work. A few of the better-known attacks based on the buffer characteristics of
a program or system include:
SYN Attack
When
a session is initiated between the Transport Control Program (TCP) client and
server in a network, a very small buffer space exists to handle the usually
rapid "hand-shaking" exchange of messages that sets up the session.
The session-establishing packets include a SYN field that identifies the
sequence in the message exchange. An attacker can send a number of connection
requests very rapidly and then fail to respond to the reply. This leaves the
first packet in the buffer so that other, legitimate connection requests can't
be accommodated. Although the packet in the buffer is dropped after a certain
period of time without a reply, the effect of many of these bogus connection
requests is to make it difficult for legitimate requests for a session to get
established. In general, this problem depends on the operating system providing
correct settings or allowing the network administrator to tune the size of the
buffer and the timeout period.
Teardrop Attack
This
type of denial of service attack exploits the way that the Internet Protocol
(IP) requires a packet that is too large for the next router to handle be
divided into fragments. The fragment packet identifies an offset to the
beginning of the first packet that enables the entire packet to be reassembled
by the receiving system. In the teardrop attack, the attacker's IP puts a
confusing offset value in the second or later fragment. If the receiving
operating system does not have a plan for this situation, it can cause the
system to crash.
Smurf Attack
In
this attack, the perpetrator sends an IP ping (or "echo my message back to
me") request to a receiving site The ping packet specifies that it be
broadcast to a number of hosts within the receiving site's local network. The
packet also indicates that the request is from another site, the target site
that is to receive the denial of service. (Sending a packet with someone else's
return address in it is called spoofing the return address.) The result will be
lots of ping replies flooding back to the innocent, spoofed host. If the flood
is great enough, the spoofed host will no longer be able to receive or
distinguish real traffic.
Viruses
Computer
viruses, which replicate across a network in various ways, can be viewed as
denial-of-service attacks where the victim is not usually specifically targeted
but simply a host unlucky enough to get the virus. Depending on the particular
virus, the denial of service can be hardly noticeable ranging all the way
through disastrous.
Physical Infrastructure Attacks
Here,
someone may simply snip a fiber optic cable. This kind of attack is usually
mitigated by the fact that traffic can sometimes quickly be rerouted.
3(A).
Computer is an electronic device which accepts data, process
data, displaying data and storing data or information. Basic parts or elements
of computer system are like hardware, software, Central Processing Unit (CPU),
speaker, and keyboard. CPU is considered to be as a brain of a computer. Data
is unprocessed information, and information is a processed data.
The
founders of computer.
Charles
Babbage. A mathematician, philosopher, inventor and
mechanical engineer, Babbage is best remembered for originating the concept of
a programmable computer. He was born on December 26, 1791, and he died in 18
October 1871 (aged 79).
Considered by some to
be “father of the computer”, Babbage is created with inventing the first
mechanical computer that eventually led to more complex designs. His varied
work in other fields has led him to be described as “pre-eminent” among the
many polymaths of his century.
Alan
Mathison Turing. Was a British pioneering computer
scientist, mathematician, logician, cryptanalyst and theoretical biologist. He
was born on 23 June 1912, and died on 7 June 1954 (aged 41). He was highly
influential in the development of computer science, providing a formalization
of the concepts of algorithm and computation with the Turing machine, which can
be considered as a model of a general purpose computer. Turing is widely
considered to be the father of theoretical computer science and artificial
intelligence.
John
Vincent Atanasoff. Was born in October 4, 1903 and he died
in June 15, 1995. Were an American physicist and inventor, best known for
inventing the first electronic digital computer.
Atanasoff invented the
first electronic digital computer in the 1930s at lowa state
college. Challenges to his claim were resolved in 1973 when the Honeywell v.
Sperry Rand lawsuit ruled that Atanasoff was the inventor of the computer. His
special purpose machine has come to be called the Atanasoff-Berry Computer.
John
von Neumann. Was a brilliant mathematician, synthesizer,
and promoter of the stored program concept, whose logical design of the IAS
became the prototype of most of its successors – the von Neumann Architecture.
He was born Neumann Janos on December 28, 1903, in Budapest, the capital of
Hungary. He was the first born son of Neumann Miksa and Kann Margit. Max
Neumann purchased a title early in his son’s life, and so became von Neumann.
Von Neumann’s interest in computers differed from that of his peers by his
quickly perceiving the application of computers to applied mathematics for
specific problems, rather than their mere application to the development of
tables.
A
short history of computer.
One
of the earliest machines designed to assist people in calculations was the abacus
which is still being used some 5000 years after its invention.
In
1642 Blaise Pascal (a famous French mathematician) invented an adding machine
based on mechanical gears in which numbers were represented by the cogs on the
wheels.
Englishman,
Charles Babbage, invented in the 1830's a "Difference Engine" made
out of brass and pewter rods and gears, and also designed a further device
which he called an "Analytical Engine". His design contained the five
key characteristics of modern computers:-
o
An input device
o
Storage for numbers waiting to be
processed
o
A processor or number calculator
o
A unit to control the task and the
sequence of its calculations
o
An output device
Augusta
Ada Byron (later Countess of Lovelace) was an associate of Babbage who has
become known as the first computer programmer.
An
American, Herman Hollerith, developed (around 1890) the first electrically
driven device. It utilized punched cards and metal rods which passed through
the holes to close an electrical circuit and thus cause a counter to advance.
This machine was able to complete the calculation of the 1890 U.S. census in 6
weeks compared with 7 1/2 years for the 1880 census which was manually counted.
In
1936 Howard Aiken of Harvard University convinced Thomas Watson of IBM to
invest $1 million in the development of an electromechanical version of
Babbage's analytical engine. The Harvard Mark 1 was completed in 1944 and was 8
feet high and 55 feet long.
At
about the same time (the late 1930's) John Atanasoff of Iowa State University
and his assistant Clifford Berry built the first digital computer that worked
electronically, the ABC (Atanasoff-Berry Computer). This machine was basically
a small calculator.
In
1943, as part of the British war effort, a series of vacuum tube based
computers (named Colossus) were developed to crack German secret codes. The
Colossus Mark 2 series (pictured) consisted of 2400 vacuum tubes.
John Mauchly and
J. Presper Eckert of the University of Pennsylvania developed these ideas
further by proposing a huge machine consisting of 18,000 vacuum tubes. ENIAC
(Electronic Numerical Integrator and Computer) was born in 1946. It was a huge
machine with a huge power requirement and two major disadvantages. Maintenance
was extremely difficult as the tubes broke down regularly and had to be
replaced, and also there was a big problem with overheating. The most important
limitation, however, was that every time a new task needed to be performed the
machine need to be rewired. In other words programming was carried out with a
soldering iron.
In
the late 1940's John von Neumann (at the time a special consultant to the ENIAC
team) developed the EDVAC (Electronic
Discrete Variable Automatic Computer) which pioneered the
"stored program concept". This allowed programs to be read into the
computer and so gave birth to the age of general-purpose computers.
Computer
generation, Generation in computer terminology is a change in technology a
computer is/was being used. Initially, the generation term was used to
distinguish between varying hardware technologies. But nowadays, generation
includes both hardware and software, which together make up an entire computer
system.
There are totally five computer generations known
till date. Each generation has been discussed in detail along with their time
period and characteristics. Here approximate dates against each generations
have been mentioned which are normally accepted.
First
Generation (1940-1956) Vacuum Tubes
The first computers used vacuum tubes for
circuitry and magnetic drums for memory, and were often enormous, taking up
entire rooms. They were very expensive to operate and in addition to using a
great deal of electricity, the first computers generated a lot of heat, which
was often the cause of malfunctions. First generation computers relied on
machine language, the lowest-level programming language understood by
computers, to perform operations, and they could only solve one problem at a
time, and it could take days or weeks to set-up a new problem. Input was based
on punched cards and paper tape, and output was displayed on printouts. The
UNIVAC and ENIAC computers are examples of first-generation computing devices.
The UNIVAC was the first commercial computer delivered to a business client,
the U.S. Census Bureau in 1951.
Second
Generation (1956-1963) Transistors
Transistor replaces vacuum tubes and ushered in
the second generation of computers. The transistor was invented in 1947 but did
not see widespread use in computers until the late 1950s. The transistor was
far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper,
more energy-efficient and more reliable than their first-generation
predecessors. Though the transistor still generated a great deal of heat that
subjected the computer to damage, it was a vast improvement over the vacuum
tube. Second-generation computers still relied on punched cards for input and
printouts for output. Second-generation computers moved from cryptic binary machine
language to symbolic, assembly, languages, which allowed programmers to specify
instructions in words. High-level
programming languages were also being developed at this time, such
as early versions of COBOL and FORTRAN. These were also the first computers
that stored their instructions in their memory, which moved from a magnetic
drum to magnetic core technology. The first computers of this generation were
developed for the atomic energy industry.
Third
Generation (1964-1971) Integrated Circuits
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. Instead of punched cards and printouts,
users interacted with third generation computers through keyboards and monitors
and interfaced with an operating system, which allowed the device to run many
different applications at one time with a central program that monitored the
memory. Computers for the first time became accessible to a mass audience
because they were smaller and cheaper than their predecessors.
Fourth
Generation (1971-Present) Microprocessors
The microprocessor brought the fourth generation
of computers, as thousands of integrated circuits were built onto a single
silicon chip. What in the first generation filled an entire room could now fit
in the palm of the hand. The 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, and 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. As
these small computers became more powerful, they could be linked together to
form networks, which eventually led to the development of the Internet. Fourth
generation computers also saw the development of GUIs, the mouse and handheld devices.
Fifth
Generation (Present and Beyond) Artificial Intelligence
Fifth generation computing devices, based artificial
intelligence, are still in development, though there are some applications,
such as voice recognition, that are being used today. The use of parallel
processing and superconductors is helping to make artificial intelligence a
reality. Quantum computation and molecular and nanotechnology will radically
change the face of computers in years to come. The goal of fifth-generation
computing is to develop devices that respond to natural language input and are
capable of learning and self-organization.
Differences
between the fifth and forth generation
Fourth generation programming languages
are designed for a specific application domain, while fifth generation
programming languages are designed to allow computers to solve problems by
themselves. Fourth generation of computer programmers need to specify the
algorithm in order to solve a problem, whereas Fifth generation of computer
programmers only needs to define the problem and constraints that need to be
satisfied. Fourth generation of computer are mainly used in data processing and
database handling applications, while Fifth generation of computer are mostly
used for problem solving in AI field.
REFERENCES
D.M. Kienzle & M.C. Elder 2003, Recent Worms: ACM workshop on Rapid
Malcoda, pp1-10, 2003.
Louw, Erick and Neil Duffy. Managing Computer Virus. Oxford
University Press. 1992.
Shelly Cashman Vermaat. Discovering Computer Fourth Edition 2008.
Thomson Course Technology (publisher).
Comments
Post a Comment