lesson 1 introduction

Reference: Reference: COMPLETE COMPUTER CONCEPTSBy: Shelly, Cashman, Waggoner

Airlines:Flight reservation (booking)Customer Information System

Offices :Personal RecordsPayroll SystemsInventory SystemsGrading SystemsE-mail/Group chatConferencingReportsEtc.

Schools:Visual AidsGrading SystemsComputer LiteracyResearchProjectsBasic KeyboardingWord Processing

Banks:Customer InformationBalance InquiryBanking SystemsCredit Applications(savings)

Peers:Social Networking(facebook)EntertainmentMeeting/Schedules

What is Computer? A computer is an electronic device, operating under the control of instruction stored in its own memory unit, that can accept data (input), process data arithmetically and logically, produce output from the processing, and store the results for future use. It is a programmable device that can store, retrieve and process data.

The real answer is that many inventions contributed to the history of computers and that a computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention.

DATA FLOW CYCLE / INFORMATION PROCESS CYCLE

Input unit Output unitProcess unit

Storage unit

Communication unit

The sequence of events in processing information

Input Units – are units that inserts data to the processor.

Process Units – are units that performs computations and operations.

Output Units – are units that displays data called file.

Communication Units – are units that transfers information through cables and telephone lines.

Storage Units – are units that stores file.

Input “You first have to get the data in” Our brain takes in information from our senses Computers need “peripherals” (extra components) to get information

in(keyboard, mice, scanners, etc.) Process Next, we need to “make sense of” the data we have

Our brain makes our body respond by talking, moving, or writing. Computers need “peripherals” to do the task.

Output get the results out from the process, and present them in a useable way

Our brain compares this to what we know and decides whether it is important enough to remember or not.

Computer uses the CPU (the main chip inside) to make decisions, do calculations, and organize data

COMPARISON TO HUMAN ANATOMY

CHARACTERISTICS OF A COMPUTER

Machine

Electronic

Automatic Manipulates data

Has Memory

It has Logical Function

ADVANTAGES OF A COMPUTER

Speed

Accuracy

Repetitiveness

Storage

Programmable

It can only do what is designed or programmed to do.

It cannot correct input data It cannot think and derive meanings from

objects. It can only process jobs expressed in a

finite number of steps leading to a precise defined goal.

It cannot completely avoid making errors due to power fluctuations, system malfunctions and human disorders.

LIMITATIONS OF A COMPUTER

FOUR BASIC FUNCTION OF A COMPUTER

Input – using the input devices to tell the computer what to do.

Output – the displaying of data that was processed by the processor

Process – following the instruction of the user’s input and putting it to action.

Storage- the storing of information that have been processed.

COMPONENTS OF A COMPUTER

Data is processed by specific equipment that is often called computer hardware.

COMPONENTS OF A COMPUTER

INPUT DEVICES

Input devices are used to enter data into a computer. A common input device is the keyboard. As the data is entered, or keyed, it is stored in the computer and displayed on a screen.

COMPONENTS OF A COMPUTER

PROCESSOR UNIT

It contains the electronic circuits that actually cause the processing of data to occur. The processor unit is divided into two parts, the central processing unit and main memory.

COMPONENTS OF A COMPUTER

Central Processing Unit

The central processing unit (CPU) contains a control unit that executes the program instructions and an arithmetic/logic unit (ALU) that performs math and logic operations.

+

-

*

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Arithmetic operations

>

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=

Logical operation

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COMPONENTS OF A COMPUTER

Main Memory

Main memory is also called primary storage, is a part of processor unit. Main memory electronically stores data and program instruction when they are being processed.

COMPONENTS OF A COMPUTEROUTPUT DEVICE

A component that gives out to the user the results of the processed data. The information is transmitted from the CPU to this output device.

e.g. printer, monitor, and speakers.

COMPONENTS OF A COMPUTER

AUXILIARY STORAGE UNIT

Auxiliary storage, store instructions and data when they are not being used by the processor unit.e.g. disk drive, magnetic disk, magnetic tape.

CATEGORIES OF COMPUTER

Computers are generally classified according to their size, speed, processing capabilities and price. They are, Microcomputers, Minicomputers, Main Frame, And Super Computer.

CATEGORIES OF COMPUTER

MICROCOMPUTERS

Also called personal computers or micros, are the small desktop-sized systems that have become so widely used in recent year. These machines are generally priced under P20,000. This category also includes hand-held, notebook, laptop, portable, and super microcomputers.

CATEGORIES OF COMPUTER

MINICOMPUTERS

Are more powerful than microcomputers and can support a number of users performing different tasks. Originally developed to perform specific task such as engineering calculations, their use grew rapidly as performance and capabilities increased. These can cost approximately P40,000..

CATEGORIES OF COMPUTER

MAINFRAME

Are large systems that can handle hundreds of users, store large amounts of data, and process transactions at a very high rate. The price range for mainframes is from several hundred thousand dollars to several million dollars.

CATEGORIES OF COMPUTER

SUPERCOMPUTERS

Are the most powerful category of computers and, accordingly, the most expensive. The capability of these systems to process hundreds of millions of instructions per second is used for such applications as weather forecasting, engineering design and testing, space exploration, and other jobs requiring long and complex jobs.

COMPUTER SOFTWARE

A computer is directed by a series of instructions called a computer program, which specifies the sequence of operations the computer will perform. To do this, the program must be stored in the main memory of the computer. Computer programs are commonly referred to as computer software.

COMPUTER SOFTWARE

CATEGORIES OF SOFTWARE

System Software

Application Software

COMPUTER SOFTWARE

SYSTEM SOFTWARE

System software consists of programs that are related to controlling the actual operations of the computer equipment. An important part if the system software is as set of programs called operating system.

COMPUTER SOFTWARE

Operating System

The instructions in the operating system tell the computer how to perform functions such as how to load, store, and execute an application program and how to transfer data between the input/output devices and main memory.

DOS

LINUX

MACINTOSH

WINDOWS

UNIX

COMPUTER SOFTWARE

APPLICATION SOFTWARE

Application software consists of programs that tell a computer how to produce information. When you think of the different ways that people use computers in their careers or in their personal lives, you are thinking of examples of application software.

COMPUTER SOFTWARE

Application Software Packages

Personal computer users, often use applications software packages. Some of the most commonly used packages are: word processing software, electronic spreadsheet software, computer graphics software, and database software.

COMPUTER SOFTWARE

Word Processing Software

Word processing software is used to create and print documents that would otherwise be prepared on a typewriter. A key advantage of word processing software is its capability to make changes easily in documents, such as correcting spelling, changing margins, adding, deleting, or relocating entire paragraphs.

COMPUTER SOFTWARE

Electronic Spreadsheet Software

Electronic spreadsheet software allows the user to add, subtract, and perform user-defined calculations on rows and columns of numbers. These numbers can be changed and spreadsheet quickly recalculates the new results. It eliminates the tedious recalculations required with manual methods

COMPUTER SOFTWARE

Graphic Software

Graphics software converts numbers and text into graphic output that visually conveys the relationships of the data. Some graphic software allows the use of color to further enhance the visual presentation. Line, bar, and pie charts are the most frequent forms of graphic output.

COMPUTER SOFTWARE

Database Software

Database software allows the user to enter, retrieve, and update data in an organized and efficient manner. It has flexible inquiry and reporting capabilities that allow users to access the data in different ways and create customs reports.