Download UNIVERSITY OF NAIROBI DEPARTMENT OF REAL ESTATE

UNIVERSITY OF NAIROBI
DEPARTMENT OF REAL ESTATE & CONSTRUCTION MANAGEMENT
COMPUTING 1-BQS 214
ASSIGNMENT BY
MBATI DELORES WEKOYE
STUDENT NO :B66/31061/2011
LECTURER: MR. EMMANUEL BEAUTTAH MUTAI
FEBRUARY 2013
1. Why is computer known as data processor?
A computer is known as data processor because it converts data fed into it into readable material which
is produced as a finished product upon being fed into the computer by typing. It is displayed and
printed out by its output components. It processes data into information.
A computer is therefore an electronic device which manipulates or transforms data. It accepts data,
stores data, processes data according to a set of instructions, and also retrieves the data when required.
Hence it is known as a data processor.
2. Explain in brief the various generations in computer technology?
Answer
There are five generations of computers; first generation, second generation, third generation, fourth
generation and fifth generation.
i. FIRST GENERATION
These were the first computers to be assembled in 1940 and were in operation until 1956.
They used vacuum tubes for circuitry and magnetic drums for memory, and were very large, taking up
entire rooms. They were very expensive to operate and in addition to using a great deal of electricity,
generated a lot of heat, which was often the cause of malfunctions. . They had a small memory capacity
and therefore were very slow.
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.
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.
ii. SECOND GENERATION
The second generation computers were in operation from 1956 to 1963.
They used transistors instead of vacuum tubes. Transistors were 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. Secondgeneration computers still relied on punched cards for input and printouts for output.
The first computers of this generation were developed for the atomic energy industry.
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iii. THIRD GENERATION
Integrated circuits were introduced into the computer giving rise to third generation computers in 1964.
It was small in size and consumed less power. This was achieved by producing smaller transistors which
were placed on silicon chips, called semiconductors. They drastically increased the speed and efficiency
of computers and had a larger memory capacity.
Instead of punched cards and printouts, users interacted with 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 therefore
became smaller and cheaper.
iv. FOURTH GENERATION
These were developed in 1971 and are in operation. Thousands of integrated circuits were mounted
onto a single silicon chip. Where as the first generation computers filled a room, some fourth
generation computers could fit on the palm of the hand. All the components of the computer from the
central processing unit and memory to input and output controls were located on a single chip.
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.
v. FIFTH GENERATION
Fifth generation computing devices are based on artificial intelligence such as voice recognition. They
are still being developed and more advanced technology is being invented. The use of parallel and
super-conductors is helping to make artificial intelligence a reality. The aim of fifth generation
computers is to develop devices that respond to natural language input and are capable of learning and
self-organization.
3. Write a short note on the fifth generation of computer. What makes the difference from the fourth
generation computer?
The fifth generation computing devices are based on artificial intelligence such as voice recognition.
They are still being developed and more advanced technology is being invented. They use parallel and
super-conductors in order to achieve artificial intelligence .
These computers use Ultra-Large Scale Integration chips with millions of transistors placed in
a single integrated circuit.
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The fifth generation computers are different from the fourth generation computers because of the
technology used.Their devices are based on artificial intelligence while the fourth generation computers
depend on normal data input which they process.
4. Why did the size of computer get reduced in third generation computer?
The third generation computers reduced in size since they made use of integrated circuits which were
very small as compared to vacuum tubes and big transistors used before . The transistors on the
intergrated circuits were much smaller than the ones used in second generation computers.
5. Give short notes on the following
a) Versatility
A computer's versatility is the ability of computers to handle multiple processes and programs
simultaneously. For a computer to be versatile, it must have a current operating system,
contemporary hardware and a suitable amount of peripherals. Computers are capable of
performing any task, provided the task can be reduced to a series of logical steps.
The combination of better microprocessors, better graphic and sound cards with software capable
of handling many tasks gives the computer its versatility.
b) Storage
Computer data storage is a technology consisting of computer components and recording media
used to retain digital data. This is determined by its memory capacity.
Computer storage is divided into two:1.
Primary Storage
This type of storage is also referred to as main storage. It can also be termed temporary storage
because when you switch the computer off, all information that was stored in memory is lost.
This holds data in memory. A computer has two types of memories;
RAM (Random access memory) and ROM(Read only memory)
RAM is used in the normal running of the computer and it determines the speed of the computer.
These memories are found in the computer hard drive usually built inside the computers. They
range from 1 GB to 4 TB in capacity. The types of hard drives are PATA, SATA and SCSI.
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2.
Secondary Storage
This is a type of computer storage that holds data on hard disks, tapes and other devices
requiring input/output operations. Secondary storage is also referred to as auxiliary storage and
comprise floppy disks, compact disks, USB disks such as flash disks, Cds and Dvds. It can also
be called permanent storage because data that is stored on these devices remain there until
physically changed or deleted. The data is not lost when the power is turned off.
These storage devices are also used as back up devices for safely storing data in case the
computer gets damaged by viruses or is physically destroyed by fire or is stolen. The External
hard disks have a very big storage capacity and can store a lot of data. It is advisable to keep
these devices far from the computer to help retrieve data in case of the mentioned occurrences.
The External hard drives come in USB, Firewire, SATA and SCSI.
c) Slide rule
This is a mechanical analog computer which is used for multiplication, division, and for
functions such as roots, logarithms and trigonometry. It is however not normally used for
addition or subtraction.
Slide rules come in a diverse range of styles and generally appear in a linear or circular form
with a standardized set of markings (scales) essential to performing mathematical computations.
Slide rules manufactured for specialized fields such as aviation or finance typically feature
additional scales that aid in calculations common to that field.
It was developed in the 17th century by William Oughtred and others based on the emerging
work on logarithms by John Napier. He discovered the logarithm which made it possible to
perform multiplications and divisions by addition and subtraction. This was a great time saver
but there was still quite a lot of work required. The mathematician had to look up two logs, add
them together and then look for the number whose log was the sum. Edmund Gunter soon
reduced the effort by drawing a number line in which the positions of numbers were proportional
to their logs.
Before the advent of the pocket calculator, it was the most commonly used calculation tool in
science and engineering. The use of slide rules continued to grow through the 1950s and 1960s
even as digital computing devices were being gradually introduced until around 1974 when the
electronic scientific calculator made it largely obsolete and most suppliers left the business.
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d) Babbage’s analytical Engine
In 1791 Charles Babbage designed the Analytical Engine which was a special-purpose machine designed
to tabulate logarithms and trigonometric functions by evaluating finite differences to create approximating
polynomials. It had many essential features found in the modern digital computer. It was programmable
using punched cards, an idea borrowed from the Jacquard loom used for weaving complex patterns in
textiles.
The Engine had a 'Store' where numbers and intermediate results could be held, and a separate 'Mill'
where the arithmetic processing was performed. It had an internal repertoire of the four arithmetical
functions and could perform direct multiplication and division. It was also capable of functions for which
we have modern names: conditional branching, looping (iteration), microprogramming, parallel
processing, iteration, latching, polling, and pulse-shaping, amongst others, though Babbage nowhere used
these terms. It had a variety of outputs including hardcopy printout, punched cards, graph plotting and the
automatic production of stereotypes - trays of soft material into which results were impressed that could
be used as molds for making printing plates.
Babbage did not write down an explicit set of instructions for the engine in the manner of a modern
processor manual. Instead he showed his programs as lists of states during their execution, showing what
operator was run at each step with little indication of how the control flow would be guided.
Babbage's first attempt at a mechanical computing device, the Difference Engine, was a special-purpose
machine designed to tabulate logarithms and trigonometric functions by evaluating finite differences to
create approximating polynomials. Construction of this machine was never completed because Babbage
had conflicts with his chief engineer the British government withdrew its funding for the project. It was
not until the 1940s that the first general-purpose computers were actually built.
6. Distinguish between micro-computers and mainframe computers
Microcomputers are computers with a microprocessors as their Central Processing Units. They occupy
physically small amounts of space. Many microcomputers are also personal computers. They are used
by small businesses, colleges and schools since they are relatively cheaper as compared to mainframe
computers.
Mainframes are computers used mainly by large organizations for critical applications, typically bulk
data processing such as census, industry/consumer statistics, insurance matters and financial
transaction processing. They have a very large processing speed . Due to this high speed, main-frame
computers are used for complex scientific calculations, large data processing application and for complex
graphics applications.
Main-frame as opposed to micro-computers can support multi-users and multi-programming.
The micro-computers support a single processing unit while the main-frame is implemented using two or
more central processing units (CPU) enabling it to have a larger data storage capacity.
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