TOPICS FOR PRELIMS

COMPUTER

What is “COMPUTER”?A computer is a device

that store and process data.What is “DATA”?

These are what we call raw facts.What are “RAW FACTS”?

These are the letters, symbols, and numbers

CHARACTERISTICS OF COMPUTER

1. ElectronicAll computers are powered by electricity.2. ProgrammableAll computers are able to follow a set of

instructions called programs, from which a user may derive the specific information he wants.

3. Storage capabilityAll computers are able to store data

intended for later use. This characteristic makes them to electronic filing cabinets.

4. Retrieval capability

All computers are able to regain stored programs and data. Storing is a useless exercise if programs and data cannot be retrieved for later use.

5. Processing capability

All computers are able to process data that is useful information can be gleaned after the computer has performed the necessary operational instruction on the raw data it is fed.

USES OF COMPUTERS

a. On medicine

Example: The computer tonography at Makati Medical Center used to examine the nervous system and the more difficult areas of the human body to detect tumors, strokes, cancer and other lesions.

b. On money and Banking

Examples: Automated Teller Machine (ATM), electronic fund transfer and credit cards.

c. On factories

Examples: Computer-aided design (CAD), computer-aided manufacturing (CAM), and robots and hands in modern factories.

d. On education

Examples: Computer-aided learning (CAL) and computer-aided instruction (CAI).

e. On Information and Communication

Examples: Postal services through electronic mail (e-mail), electronic libraries through the INTERNET and the use of cellular phones.

f. On the Houses/Offices of the Future

Examples: Computer-operated appliances equipment.

COMPUTER CAPABILITIES

1. SPEED

The computer can process and calculate large amounts of data.

2. ACCURACY/ACCURATE

It can process the right data quickly with 100% correctness.

3. AUTOMATIC

It can execute instructions automatically.

4. ENDURANCE

Durable

5. WIDE RANGE OF APPLICATION

Computer are essential tools of everyday living from simple household tasks to the most complicated activities.

6. STORE AND RECALL DATA

Computer can retrieve or get information from memory.

7. SELF CHECKING

It verifies the correctness of it’s work to ensure that all data are correct and accurate.

8. REPETITIVENESS

Computers never complain or get bored like us. They can do tasks many time as a computer operator wants to be done.

COMPUTER LIMITATIONS

1. Computers are prone to viruses.

2. Computers cannot do what they are not instructed to do.

3. Computers are subjected to physical failure.

4. Computers cannot correct wrong instructions.

5. Computers cannot perform creative thinking.

CHARACTERISTICS OF COMPUTER

1. Programmable

2. Storage

3. Reduction of Cause

4. Versatility

5. Arithmetic and Logical Operations

6. Reliability

7. Automation

8. Diligence

9. Consistency

10.Precision

DATA PROCESSING

What is “Data Processing”?

It is the process of transforming data into useful and meaningful information.

What is “DATA”?

These are collection of facts such as numbers, letters or special symbols relating to events that take place.

Where do “Information” refers?

It refers to data that has been organized and processed so that it becomes meaningful.

ORIGIN

DATA PROCESSING CYCLE

OUTPUT

PROCESSING

Feedback

INPUT

Input

The data or source information entering the system to be processed by a computer. Input may also be computer programs that will process the data. Processing

The orderly planned actions by the computer (sorting, classifying, calculating, and other data operations) with the information or data that is entered into the system. Output

The results of processed data or information. The output may be sent to a disk, CD or USB flash drive (soft copy) or to a painter (hard copy).

Input Activities

1. Codingdata has been transformed into more concise.

2. Editingthe elimination of data that are not needed for processing.

3. Verifyingthe checking of accuracy of the coded data.

Processing Activities

1. Recordingdocumentation of data In order to produced an information.

2. SortingArrange data in space order such as: ascending, descending.

3. ClassifyingGroups data into categories.

4. CalculatingRefers to computation perform on data either in the same storage.

5. SummarizingRefers to aggregation of data such as: total, average and standard deviation.

Output activities

1. ReproducingRefers in making copies of data either in the same storage.

2. StoringPlacing similar data into farther references.

3. RetrievingRecovering the data stored.

What is ICT?

INFORMATION AND COMMUNICATION TECHNOLOGY (ICT) encompasses the use of computers, telecommunications, and office systems technologies.

There are types of components to consider in creating an ICT resource:

1. tools to access services, most obviously telephone and personal computers.

2. telecommunication links that course the tools to those services.

3. transaction processing hardware and software, and

4. Information stores.

CLASSIFICATIONS OF COMPUTERI. According to sizeSupercomputers

Supercomputers are widely used in specific applications such as aerodynamic design stimulation, processing of geological data. Supercomputers are most powerful computers. Because of their size and expense, supercomputers are relatively

rare. Supercomputers are used by universities, government agencies,

and large businesses.

Mainframe ComputersMainframe Computers are usually

slower, less powerful and less expensive than supercomputers.

Minicomputers

Are smaller than mainframe, general purpose computers, and give computing power without adding the prohibit expenses associated with larger systems.

Workstations• Powerful single-user computers.• Used for tasks that require a great deal of number-crunching power, such as product design and computer animation.•Often used as network and Internet servers.

MicrocomputersMicrocomputer or Personal Computer is the smallest, least expensive of all computers.Personal Computers (PC)

Laptop DesktopPalm Top Tablet

II. According to Technology Analog Computers

These computers recognize data as continuous measurement of a physical property (voltage, pressure, speed and temperature).

Example: Automobile speedometer Digital Computers

These are high speed programmable electronic devices that perform mathematical calculations, compare values and store results. Hybrid Computers

A computer that processes both analog and digital data.

III. According to purpose General Purpose Computers

A machine that is capable of carrying out some general data processing under program control. Special Computers

A computer that is designed to operate on an restricted class of problems.

ACCORDING TO CAPACITY

1.Microcomputers2.Minicomputers3.Super computers4.Mainframe computers

HISTORY OF COMPUTERCharles Babbagefather of modern computer

William “Bill” Gates monopolize computer1993 ( most powerful people)

he establish the microsoft company

rated 53rd among the youngest at age of 37 among the chief executive.

1997 ( ranked 2nd)

Lady Augusta Ada ByronWorld’s first programmer.

Wrote a demonstration program for Babbage’s Analytical Engine.

Charles Babbage

William “Bill” Gates

Lady Augusta Ada Byron

THREE TYPES OF DEVICES

I. Manual Mechanical DevicesThese are devices powered by

hand in hand physical effort from the user.Abacus is the first manual data

processing device developed in China in the 12th century.

Napier’s Bone is a set of rods, made of bone or ivory, each divided into nine spaces, and containing the numbers of a column of the multiplication table. This was invented by John Napier in 1617 for facilitating the operations of multiplication and division.

Gunter and Oughtred’s Slide Rule is a ruler upon which are marked several graduated scales that may be moved relative to one another so that certain calculations may be carried out. This was invented by Englishmen Edmund Gunter and William Oughtred.

Pascal’sPascaline is the gear-driven machine that can be used to add and subtract by means of rotating toothed wheels. This was invented by Blaise Pascal in 1642.

Leibniz’s Calculator utilizes the same techniques for addition and subtraction as Pascal’s device but could also perform multiplication and division as well as extract square roots. This was invented by Baron Gottfried Wilhelm Von Leibniz in 1674.

Babbage’s Analytical Engine was designed to use two types of cards one called operation cards to indicate the specific functions to be performed and other called variable cards to specify the actual data. This was invented by Charles Babbage in 1882. Babbage is known as the “Father of Computing”. Lady Augusta Ada Byron is known as the world’s first programmer and wrote a demonstration program for Babbage’s Analytical Engine.

II. Electromechanical Devices

These are devices powered by electric motor and uses relays and switches.

Hollerith’s Punched-Card Machine is a machine invented by Herman Hollerith in 1880 to tabulate census data more efficiently than by traditional hand methods.

Jacquard’s Loom is a weaving machine or a mechanical loom that used punched cards to weave fabric in a variety of patterns. This was invented by Joseph Marie Jacquard in 1804.

Harvard Mark I or Automatic Sequence Controlled Calculator was an early form of the digital computer controlled by electromechanical relays or switching devices. The electrical engineer and physicist Howard H. Aiken of Hardvard University together with the assistance of IBM and its engineers built in 1943.

III.Electronic Devices

These are devices h=which use only electrical switches and circuitry instead of mechanical relays and consist of circuit board, transistors or silicon chips.

Atanasoff-Berry Computer was the first digital computer that used binary logic circuitry and had regenerative memory. This was invented by John Atanasoff and Clifford Berry in 1942.

Electronic Numerical Integrator and Computer (ENIAC) was the first large-scale vacuum-tube computer. This was invented by John Presper Eckert and John W. Mauchly in 1943 to 1946.

Electronic Discrete Variable Automatic Computer (EDVAC) was a modern version of ENIAC, which used the stored-program concept and the binary arithmetic concept or the von Neumann’s concept. Dr. John von Neumann a Hungarian-born mathematician, proposed the idea that programs could be coded as numbers and stored with data in a computer’s memory.

Electronic Delayed Storage Automatic Computer (EDSAC) was the first full-scale computer with electronic stored programs Maurice V. Wilkes and his team at the University of Cambridge constructed the EDSAC.

Universal Automatic Computer (UNIVAC) was the first generation computer sold by Remington Rand Companies in 1951. Developed by Eckert and Mauchly.

IV.Computer Generations

First Generation-1940-1955: Vacuum Tubes

The first computers used vacuum lubes for circuitry and magnetic drums for memory.

Second Generation-1956-1963: Transistors

Transistors replaced vacuum tubes and ushered in the second generation of computers.

Third Generation-1964-1970: Integrated Circuits

The development of the integrated circuit was the hallmark of the third generation of computers.

Fourth Generation-1971-Present: Microprocessors

The microprocessor brought the fourth generation of computer, as thousands of integrated circuits were built onto a single silicon chip.

Fifth Generation-Present and Beyond: Artificial Intelligence (AI)

Fifth generation computing devices,

based on artificial intelligence, are still in development though there are some applications such as voice recognition that are being used today.

COMPUTER SYSTEM

What is Computer System?

COMPUTER SYSTEM consists of devices, programs, operating aids and procedures required to prepare and to process date, and the personnel who keep these elements efficiently functioning.

II. HARDWARE

Hardware-physical component of the computer system involved in data processing.

a. Input Devices

Keyboard-is the most commonly used input device to enter information or commands into the computer.

Mouse-is a hand-sized input devices with control buttons used to move the pointer on screen.

trackpad-is a small, touch-sensitive pad, usually a couple of inches square, which acts as an alternative to a mouse on laptop or notebook computers.

Light pen-is an input device that utilizes a light-sensitive detector to select objects on a display screen.

Optical mark reader-was designed initially to read penciled and graphic information on exam answer sheets.

Scanner-is a device that can read text or illustrations printed on paper and translate the information into a form the computer can use.

Digital camera-is a device that records images in digital form.

Microphone-is a device for converting sound waves into electrical energy.

Web camera-is a camera that is in some way connected to the world wide web or internet.

Joystick-is used in most video games to enter the player’s choices when playing computer games.

Touch screen-is a type of display screen that has a touch-sensitive transparent panel covering the screen.

Digitalizing tablet-is an output device that enables you to enter drawings and sketches into a computer.

Stylus-is a pointing and drawing device shaped like a pen.

Bar code reader-is an output device used to scan a pattern of lines using optical sensing techniques.

Sensor-is a device which responds to an output quantity by generating a functionally related output usually in the form of an electrical or optical signal.

Optical character recognition-permits users to input printed or typewritten documents with a scanner.

Voice recognition-is used either to control a computer’s operations and to issue commands to special application programs or to allow users to dictate into a computer using a microphone.

B. Ouput devices

Monitor-consists of a device that takes signals from a computer and displays them on a crt or lct screen.

Printer-is a peripheral that uses ribbon, ink or toner to output documents, images, and plain text files onto paper.

Plotter-is a device for reducing bar charts, maps, architectural drawings, and even three-dimensional illustrations.

Speaker-is a device used to produce sound.

Modern-modulates the computer output to an acceptable signal for transmission and then demodulates the signal back for computer input.

C.MEMORY-storage devices

memory-storage devices are used for storing data and operating programs through the input devices for the use of the cpu.

One BIT (BInary digiT) = 1 or 0One Byte = 8 bitsOne Kilobyte (KB) = bytes = 1,024 bytesOne Megabyte (MB) = bytes = 1,048,576 bytes = 1000 KBOne gigabyte (GB) = bytes = 1,073,741,824 bytes = 1000 MBOne terabyte (TB) = bytes = 1,099,511,776 bytes = 1000 GB

Main Memory

• Random-access memory (RAM) chips. As a computer processes data and instructions, it temporarily stores information internally or in its ram chips.

• Read-only memory (rom) chips. The switches of rom chips are set when they are manufactured and are unchangeable.

Secondary or auxiliary memory units supplement the main memory by holding parts of programs that are too large to fit into the random-access memory at one time.

• Floppy disk drive is computer hardware that holds and spins a magnetic or optical disk and reads and writes information on it.

• Hard disk drive is a rigid magnetic disk mounted in a drive unit

• Optical Disk is a direct-access disk.

• Usb (universal serial bus) flash drive is a form of a DIGITAL STORAGE DRIVE.

D. CENTRAL PROCESSING UNIT (CPU)

CPU IS THE BRAIN OF THE COMPUTER. SOMETIMES REFFERED TO SIMPLY AS THE PROCESSOR OR CENTRAL PROCESSOR, THE CPU IS WHERE MOST CALCULATIONS TAKE PLACE.

ARITHMETIC /LOGIC UNIT. IS THE PART OF A COMPUTER THAT PERFORMS ALL ARITHMETICAL COMPUTATIONS.

CONTROL UNIT SUPERVISES OR MONITORS THE FUNCTIONS PERFORMED BY ENTIRE COMPUTER SYSTEM ACCORDING TO CONDITIONS SET FORTH BY STORED PROGRAM.

MEMORY UNIT IS SOMEWHAT LIKE AN ELECTRONIC FILING CABINET CAPABLE OF HOLDING DATA OR INSTRUCTIONS.

III. SOFTWARE

SOFTWARE REFERS TO A GROUP OF COMPUTER PROGRAMS.

SYSTEM SOFTWARE CONSISTS OF PROGRAMS DESIGNED TO FACILITATE THE USE OF THE CONPUTER BY THE USER.

oOPERATING SYSTEM IS A SET OF PROGRAMS DESIGNED TO EFFICIENTLY MANAGE THE RESOURCES OF THE COMPUTER SYSTEM.

oLANGUAGE TRANSLATOR IS A SYSTEM PROGRAM THAT CONVERTS THE ENGLISH-LIKE INSTRUCTIONS USED BY THE COMPUTER PROGRAMMERS INTO THE MACHINE-READABLE CODE USED BY THE HARDWARE.

oUTILITY PROGRAM PERFORMS SUCH STANDARD TASKS AS ORGANIZING AND MAINTAINING DATA FILES.

APPLICATION SOFTWARE IS A TYPE OF PROGRAM THAT SOLVES SPECIFIC USER-ORIENTED PROCESSING PROBLEMS.

oWORD PROCESSOR IS A PROGRAM THAT ACCEPTS WORDS TYPES INTO A COMPUTER AND PROCESSES THEM TO PRODUCE EDITED TEXT.

oDESKTOP PUBLISHING SYSTEM IS A SYSTEM THAT ALLOWS YOU TO USE DIFFERENT TYPEFACES, SPECIFIES VARIOUS MARGINS AND JUSTIFICATIONS AND EMBEDS ILLUSTRATTIONS AND GRAPHD DIRECTLY INTO THE TEXT.

oSPREADSHEET IS A COMPUTER PROGRAM THAT LETS PEOPLE ELECTRONICALLY CREATE AND MANIPULATE SPREADSHEETS.

oDATABASE MANAGEMENT IS A SET OF PROGRAMS NECESSARY TO FACILITATE ADDING NEW DATA AS WELL AS MODIFYING AND RETRIEVING OF EXISTING DATA WITHIN A DATABSE.

oELECTRONIC GAME IS AN INTERACTIVE HARDWARE OR SOFTWARE PLAYED FOR ENTERTAINMENT CHALLENGE, OR EDUCATIONAL PURPOSES.

oGRAPHIC PACKAGES ARE COMPUTER PROGRAMS THAT ENABLE USERS TO CREATE HIGHLY STYLIZED IMAGES FOR SLIDE PRESENTATIONS AND REPORTS.

ROGUE SOFTWARE IS ANY PROGRAM THAT RUNS ON THE COMPUTER WITHOUT THE USER’S KNOWLEDGE AND CONSENT.

oBACK DOOR OR TRAP DOOR IS A SPECIAL PASSWORD OR STARTUP CODE THAT IS PROGRAMMED TO BYPASS NORMAL SECURITY PRCEDURES.

oLOGIC BoMBS are planted in another program by a mischievous programmer.

oWorms are self-contained programs that replicate by creating copies of them.

oVirus attaches itself to a program.