Intro to Computer

Data Processing

Fri, 03 Aug 2007 07:09:39 +0200

" class="middle" border="0">All through the different stages of civilization, man has always tried to look for ways to simplify work and to solve problem more' 'efficiently., Many problem involved numbers 'and quantities, so man started, looking for easier ways to count, and to add, to subtract, to multiply, and divide. As society has grown in both size and complexity, so has the data that is generated within it.

Data
is defined as any collection of unprocessed facts.
>> sales reports
>> inventory figures
>> test scores
>> Customer ‘s names and addresses
>> weather reports
>> photographs, drawings, and maps are considered data.

Data Processing
is the manipulation of data into a meaningful and useful form.

Information
is a collection of data or processed facts.

CATEGORIES OF DATA PROCESSING
Manual Data Processing
Mechanical Data Processing
Electronic Data Processing

Manual Data Processing
These system, employs tools and materials 'such as pencils, pens, multiple-copy forms, carbon paper and filing cabinets.

Mechanical Data Processing
Systems use a combination of manual procedures and, mechanical equipment. The system uses various devices such as typewriters, sorters, calculators, collators, tabulator, duplicators, and verifiers. Most of these system operate, on punched cards.

Electronic Data Processing
Different types of input, output, and storage devices may be interconnected to an electronic computer to process data.

" class="middle" border="0">DATA PROCESSING CYCLE

INPUT
In this step the initial data, or input data, are prepared in some convenient form for processing. The form will depend on the processing machine. For example, when electro mechanical devices are used, the input data- are punched on cards; but if electronic computers are used, the input data could be recorded on any of several types of input medium, such as cards, tapes, disks, and so on.

PROCESSING
In this step the input data are changed, and usually combined with other information, to produce data in a -more useful form. Thus, paychecks -may be calculated from the time cards, or a summary of sales for the month may be calculated, from the sales orders. The processing step usually involves A sequence of certain basic processing operations.

OUTPUT
Here the results of the preceding processing steps are, collected. The particular form of the output data depends on the use of the data. For example, output data may be paychecks for employees, a printed summary of monthly sales for management, or simply data to be stored for further processing at a later date.

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Why Computer Sometimes Fail?

Fri, 03 Aug 2007 04:41:27 +0200

>> 1. Input Errors
– garbage in – garbage out (GIGO)
>> 2. Errors in Instructing a Computer
- a program contains error
>> 3. The Communication Gap
>> 4. Improper Controls
>> 5. Lack of Standard
>> 6. Lack of manufacturer Support

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Computer Limitations

Fri, 03 Aug 2007 04:39:25 +0200

>> 1. Dependence on Prepared Instruction
- Performs only what it is programmed to do.
>> 2. Inability to Derive Meaning from Objects
- unable to recognize & respond to living objects.
>> 3. Inability to Generate Information
- Cannot generate information on its own because it is not capable to think & feel.
>> 4. It Cannot Correct Wrong Instruction
- It will do exactly what you instruct.

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Capabilities of Computer

Thu, 02 Aug 2007 10:14:33 +0200

solve more problems, more rapidly and more accurate by performing many arithmetic, logic, branching and i/o instructions.

>> 1. Ability to Perform Certain Logic
Manipulate in logical ways letters, symbols, numbers, words, etc.
>> 2. Ability to Provide New time Dimension
Work one step @ a time; it adds & subtract; it divide & multiply numbers in a tremendous time.
>> 3. Ability to Store & Retrieve Information
>> 4. Ability to Control Errors
>> 5. Ability 2 Check Itself
- computer have the capability to check its own work.

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History of Computer

Thu, 02 Aug 2007 04:19:58 +0200

" class="middle" border="0">Abacus
>> a Latin word that has its origins in the Greek words abax or abakon (meaning "table" or "tablet")
>> the first computing device
>> developed and originated form China @ 12 century A.D
>> The abacus is often wrongly attributed to China. In fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians.

" class="middle" border="0">Napier's rods or bones
>> invented by John Napier in the year 1617 a Scottish Mathematician.
>> The bones are an aid for multiplication and division. Even squares roots and powers could be done.
>> made of bones or ivory

" class="middle" border="0">Oughtred’s Slide Rule
>> invented by William Oughtred an English Mathematician.
>> consist of two movable parts/rulers place side by side by sliding the rulers 1 can quickly multiply & divide.
>> appeared in various forms in Europe during 17 century.

" class="middle" border="0">Leibniz Calculator
>> invented by Gottfried Leibniz a 17 century scientist.
>> completed his calculator in 1694.
>> additional operation was multiplication & division, as well as extract root.

" class="middle" border="0">Difference Engine
>> By 1822 the English mathematician Charles Babbage
was proposing a steam driven calculating machine
>> the size of a room,
>> Difference Engine
>> This machine would be able to compute tables of numbers, such as logarithm tables

" class="middle" border="0">Analytic Engine
>> Babbage was not deterred, and by then was on to his next brainstorm, which he called the Analytic Engine. This device, large as a house and powered by 6 steam engines, would be more general purpose in nature because it would be programmable
>> the fathers of the modern computer

" class="middle" border="0">Holerith’s Punch Card
>> invented by Herman Holerith a statistician of the Bureau of Census
to help process the result of the 1890 census
>> 3”x5” punched card to record the data
>> The data to be processed were coded as a hole & past between metal pins.

" class="middle" border="0">MARK 1
>> Howard Aiken
>> Automatic Sequence Controlled Calculator
>> 50 ft. long / 8 ft. High
>> 700,000 moving parts

" class="middle" border="0">ENIAC(Electronic Numerical Integrator and Calculator)
>> 1945
>> Built by Presper Eckert Jr. and John V. Mauchly
>> Calculations for Hydrogen Bomb
>> 18,000 vacuum tubes
>> 5,000 addition/sec

" class="middle" border="0">EDVAC(Electronic Discrete Variable Auto- Computer )
>> Jon Von Neumann
>> Stored Program
>> Permanent set of instruction

" class="middle" border="0">EDSAC(Electronic Delay Storage Automatic Computer )
>> more accurate than EDVAC

" class="middle" border="0">UNIVAC(Universal Automatic Computer )
>> 1952
>> the first digital computer handling both numeric and alphabet
>> the first commercially successful computer by Eckert and Mauchly

Computer Generations
" class="middle" border="0">The First Generation, 1951-1958
" class="middle" border="0">The Second Generation, 1959-1964
" class="middle" border="0">The Third Generation, 1965-1870
" class="middle" border="0">The Fourth Generation, 1970-Present
" class="middle" border="0">The Fifth Generation, Future

" class="middle" border="0">Characteristics of 1st Generation
>> Thousands of vacuum tubes
>> used a lot of electricity
>> great deal of heat generated
>> required extensive air conditioning
>> subject to frequent burnout
>> bulky; occupied a lot of floor space
>> slow

" class="middle" border="0">Characteristics of 2nd Generation
>> uses transistors (much smaller than vacuum tube)
>> consumed less energy
>> faster and more reliable
>> less bulky; less expensive

" class="middle" border="0">Characteristics of 3rd Generation
>> Used integrated circuits (ICs)
>> thousands or millions of electronic circuits etched on chips of silicon
>> sometimes called chips
>> improvement over first and second generations

" class="middle" border="0">Characteristic of 4th Generation
>> Used microprocessor
>> birth of a microprocessor in 1971
>> Apple computer:1977; IBM micro: 1981

" class="middle" border="0">Characteristic of 5th Generation
>> powerful “intelligent” computers
>> trademark: AI
>> able to reason and draw inferences
>> able to learn from mistakes

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