Transcript Fundamentals of Computer

IT Fundamentals of
Computer
Mark Anthony P. Cezar, MIT
Learning Objectives
 Explain what a computer is and how it processes data to
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produce information
Identify the four operations of the information processing
cycle: input, process, output and storage
Explain how the operations of the information processing
cycle are performed by computer hardware and software
Identify the major categories of computers
Explain the responsibilities of information system
personnel
Explain the use of computers in our world
Describe and discuss the evolution as well as the history
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of Computers
Computer Defined
 An electronic device designated to
manipulate useful information
 An electronic device, operating under the
control of instructions stored in its own
memory unit, that can accept data,
process data arithmetically and logically,
produce output from the processing, and
store the results for future use
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Generations of Computers
First Generation (1952 – 1958)
 Awesome in size
 Controlled by thousands of vacuum tubes or valves
 Consumes great amount of power that often resulted
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in overheating and failure
The operators cannot recognize whether the
breakdown was in the programming or in the
machine
Information were stored on punched cards as well as
on magnetic tapes
The language level used was machine language
which used numbers
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Generations of Computers
Second Generation Computer (1959-1964)
 Development of assembly or symbolic
language
 Development of high level language such
as Fortran (1954) and Cobol (1959)
allowed programmers to give more
attention to solving problems
 Uses transistors (used less power and did
not get so hot quickly)
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Generations of Computers
Third Generation Computers (1965-1970)
 Uses Integrated Circuit, commonly
known as the silicon chip, which
revolutionized electronic
 If later progressed to Large Scale
Integration (LSI), where few chips could
replace several hundred thousands of
transistors
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Generations of Computers
Fourth Generation Computer (1971-present)
 Uses microprocessor, a chip which contains all
the main electronic components of a compound
 If made possible to build computers to enormous
logical capacity and reliability, more cheaply and in
a very small space
 Very Large Space Integration (VLSI) was
achieved
 Microprocessors led to the development of
microcomputers
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History of Computers
 500 BC – the Chinese invented the Abacus,
considered to be the first computer device,
which can perform simple addition and
subtraction operations.
 1617 – John Napier, a Scottish
mathematician, invented the NAPIER’S Bone
– a table of logarithms made of ivory
 1630 – William Oughtred, an English
mathematician, invented the SLIDE RULE, a
device made of wood with movable scales
arrange to slide opposite each other
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History of Computers
 1642 – Blaise Pascal, a French mathematician,
invented the PASCALINE – the first mechanical
calculating machine
 1694 – Gottfried Wilhelm von Leibniz, a German
mathematician. His machine, the LEIBNIZ
MACHINE, considered of a stepped cylinder that
could perform the four fundamental operations and
square root.
 1801 – Joseph Marie Jacquard, a French weaver
and designer, devised the JACQURD LOOM
which used hole-punched cards. This machine
wove variety of patterns
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History of Computers
 1822 – Charles Babbage, an English mathematician
and is known to be the “Father of Modern Computer”,
invented the DIFFERENCE MACHINE. This machine
was capable of computing mathematical tables and
solves polynomial equation
 1833 – Charles Babbage also invented the
ANALYTICAL MACHINE designed to perform complex
mathematical calculations. This was considered to be
the first general purpose computer
 1887 – Herman Hollerith, an American statistician and
founder of Tabulating Machine Company (now called
International Business Machine or IBM) invented the
CENSUS MACHINE
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History of Computers
 1892 – William Seward Burrough, an American
inventor, designed a key-driven machine that
produced a hardcopy. This was called
ADDING/CALCULATING MACHINE.
 1944 – Burrough invented the MARK 1 or ASSC
(Automatic Sequence Controlled Calculator) machine
that contains more than 15,000 vacuum tubes some of
which are 3 feet tall
 1945 – John Presper Eckert, Jr. and William Mauchly
from the University of Pennsylvania invented the
ENIAC (Electronic Numerical Integrator and
Computer) that had the capacity of 5,000
computations per second
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History of Computers
 1948 – The IBM developed a more different
design than the ENIAC – the SSEC
(Selective Sequence Electronic Calculator)
 1950 – Eckert Jr. and Mauchly again
developed a machine The UNIVAC 1
(Universal Automatic Computer)which could
perform 10,000 computations per second.
The IBM again developed a machine that
could perform 100,000 computations per
second and can store data internally. The
machine was the IBM 704
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History of Computers
 1963 – Digital Equipment Corp. introduced the
PDP-8, regarded as the first successful
minicomputer
 1977 – Two young computer enthusiasts, Steven
Jobs and Steve Wozniak, collaborated to create
and build their Apple II computer on a makeshift
production line in Job’s garage
 1981 – IBM introduced its hat into the personal
computer ring with the announcement of the IBM
PC. It sold 35,000 on its first year of release.
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Applications of Computers
 In the scientific and engineering fields, it
provides inexpensive and accurate
computation for better designs of devices or
machines and more discoveries made in less
time
 In the business world, it is used in the
preparation of payrolls, in recording accounts
receivables, in keeping tracks or inventions
 In banks, insurance companies, hospitals,
and government offices, records are
computerized
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Applications of Computers
 Large firms and offices such as PLDT,
Meralco and MWSS prepare invoices with
computers
 Provide instantaneous and accurate data
for airlines, hotels and check-out counters
in the department stores
 Now becoming an everyday tool not only
in the offices but in homes as well
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Characteristics of Computer
 It is a machine – can only do things for it was
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designed
It is electronic – runs on electrical energy through
its electronic components
It is automatic – runs continuously once started
It can manipulate data – following specified
instructions, it can perform arithmetic functions
and can compare data
It has memory – the ability to read instructions and
store these
It has logic functions – can produce results after
instructions were fed into it
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Computer Limitations
 Dependence on prepared instructions
 Inability to derive meanings from objects
 Inability to generate information
 It cannot correct wrong instructions
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Why Computers Sometimes Fail
 GIGO (Garbage In Garbage Out).
Computer error may result from
erroneously entered input.
 Programs contain errors or “bugs” that do
not become evident until a specific set of
circumstances arises.
 “Users” do not understand each other’s
needs or have not communicated
successfully.
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Why Computers Sometimes Fail
 Improper controls can lead to sabotage the
company and invasion of privacy
 Lack of standard results in problems when an
organization obtains new equipment, hires
new computer professionals, and attempts to
provide some consistent set of procedures to
be adopted by its computing staff
 Manufacturer fails to supply needed spare
parts, trained technicians, or that particular
machine model is no longer in production
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Classification of Computers
Classification by purpose
 General-Purpose Computers - A computer
that has the ability to store different
programs of instructions and thus to
perform a variety of operations.
 Special-Purpose Computers - A computer
designed to perform one specific task
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Classification of Computers
Classification by Type of Data Handled
 Digital Computers – a machine that specialize in
counting of items that are distinct from one another,
e.g. Text, integers, morse code
 Analog Computer – machine that deals with quantities
that are continuous variable. This means that no
individual elements can be identified from any other
element, e.g. Light, voice, and video
 Hybrid Computers – machine that combines the
measuring capabilities of the analog computer and the
logical and control capabilities of the digital computer
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Classification of Computers
Classification of Computers Acc. to Capacity
 Microcomputers – it has from 4K to 64K
storage locations and is capable of
handling small, single-business
applications such as sales analysis,
inventory, billing and payroll.
 Minicomputers – usually have from 8K to
256K memory storage locations. They can
do operation like airline reservations
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Classification of Computers
 Medium-size Computers – it usually has memory sizes
ranging from 32K to 512K. They can serve the needs of a
university.
 Large Computers – it has storage capabilities from 512K to
819K. Speed is measured in terms of nanoseconds as
compared to smaller computers where speed is measured in
terms of microseconds. They can be used in government
agencies and in the development of space technology
 Supercomputers – machines that have capabilities far beyond
even the traditional large-scale systems. Their speed is in the
100-million-instruction per second. They are essential for
applications ranging from nuclear weapon development to
accurate weather forecasting.
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