Introduction to Computers

What is a Computer?

Computer Is a programmable electronic device that can store, retrieve and process data.

What is a System?

System Is a combination of components working together.

What is a Computer System?

Computer System Is a group of elements performing together to process data.

Three Components of a Computer Hardware – Refers to the physical components of the computer system Software- is a computer program Peopleware- Is the one who uses computer

Classification of Computers Mainframes Minicomputers Microcomputers

Mainframes Is large, expensive, very powerful computer that can handle hundreds or thousands of connected users simultaneously. These are characterized by large internal memory storage and a comprehensive range of software and peripheral equipment that may be connected.

Mainframes

Minicomputers Is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user system (mainframe computers) and the smallest single-user systems (microcomputers or personal computers). Can support up to 4,000 connected users at the same time.

Minicomputers

Microcomputers Is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers.

Microcomputers

Classification of Hardware Peripheral Devices Central Processing Unit Mass Storage System

Peripheral Devices Is any external device attached to the central portion of the computer. Examples: Keyboards, Monitors, printers, modem

Central Processing Unit Is that part of a computer that performs calculations and controls the other parts of the computer. The “brain” of the computer

Mass Storage System Is where you put the data you need immediately at hand Designed to hold megabytes and retrieve them

Types of Peripheral Devices Input Devices- are used to put data into your program such as keyboard, mouse, penlight, scanner and joystick Output Devices- are used to display and generate information such as monitor, printer, and speaker Input and Output Devices- are used both for entering data into and extracting data from a computer such as touch screen.

Parts of the Central Processing Unit Motherboard- is the printed circuit board in the computer system that holds the microprocessor, additional processor chips, the BIOS ROM, expansion slots, and the wires that composes the bus.

Motherboard

Parts of the Central Processing Unit Memory- is the internal storage area in the computer

Parts of the Central Processing Unit CD ROM DRIVE

Parts of the Central Processing Unit DVD ROM Drive

Parts of the Central Processing Unit Hard Drive

Parts of the Central Processing Unit Floppy Drive

Parts of the Central Processing Unit Power Supply- is a supply electrical power

Parts of the Central Processing Unit CPU- or the processor is the portion of a computer system that carries out the instructions of a computer program, and is the primary element carrying out the computer’s functions.

Parts of the Central Processing Unit Computer fan- is any fan inside a computer case used for cooling purposes, and may refer to fans that draw cooler air into the case from the outside, expel warm air from inside, or move air across a heat sink to cool a particular component.

Parts of the Central Processing Unit Heat Sink- is a colloquial term for a component or assembly that transfers heat generated within a solid material to a fluid medium, such as air or liquid.

Parts of the Central Processing Unit Video Card- is an expansion card whose function is to generate and output images to a display.

Parts of the Central Processing Unit Modem- is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information.

Parts of the Central Processing Unit Sound Card- is a computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs.

Parts of the Central Processing Unit Ribbon Cable- is a cable with many conducting wires running parallel to each other on the same flat pane.

Types of Memory RAM (Random Access Memory) – is also known as the main memory. You can both write data into and read data from RAM. - It is volatile, which means that it requires a steady flow of electricity to maintain its contents. -When the power is turned off, whatever data was in RAM is lost.

Types of Memory ROM (Read-only Memory) – cannot be written to. Computers almost always contain some read-only memory that holds instructions for starting up the computer.

Classification of Software System Software- is the software that controls application processing and hardware resources such as memory, disk space, and peripheral devices. Application Software- is a program that is created to assist users with a specific task. Programs to perform word processing, manipulate spreadsheets, manage database, and communicate with other computers are some of the popular applications.

Classification of Software's Programming Language- is an artificial language designed to express computations that can be performed by a machine, particularly a computer.

Types of System Software Operating System- is the software on a computer that manages the way different programs use its hardware, and regulates the ways that a user controls the computer.

Types of System Software Utilities- is designed to help analyze, configure, optimize and maintain the computer. A single piece of utility software is usually called a utility or tool. - focuses on how the computer infrastructure (including the computer hardware, OS, application software and data storage) operates.

Types of Application Software Wordprocessor Spreadsheet Database Management System Graphics Desktop Publisher Games Educational Accounting Package

Wordprocessor

Spreadsheet

Database Management System

Graphics

Desktop Publisher

Educational

Accounting Package

Types of Programming Languages according to generation: First Generation Language-Machine Language Second Generation Language- Assembly Language Third Generation Language- Basic, Pascal, C, COBOL, Fortan Fourth Generation Language- SQL, PowerBuilder Fifth Generation Language- Visual C++, Delphi, VB, Visual FoxPro

Types of Programming Languages according to Level: Lowest Level- Machine Language Low Level- Assembly Language Middle Level- C, C++ High Level- Basic, Pascal, COBOL, FoxPro Highest Level- Human Language or Natural Language

PC Start-Up Sequence POST- Power On Self Test- is the first program executed when a PC is turned on or reset. When the post completes, the computer emits a beep or several beeps. MS-DOS Windows 95

Boot and Reboot Procedure Warm Reboot Cold Reboot

What is a Network?

Network Is a collection of computers and devices connected by communications channels that facilitates communications among users and allows users to share resources with other users.

Advantages of Networking Peripheral Sharing File Sharing Security

Types of Network Local Area Network (LAN) Metropolitan Area Network (MAN) Wide Area Network (WAN)

Local Area Network (LAN) Is a network that connects computers and devices in a limited geographical area such as home, school, computer laboratory, office building, or closely positioned group of buildings.

LAN is made up of the ff: File Server Clients or Workstations Network Interface Cards Cable Protocol Software Network Software Operating System Software

Local Area Network

Metropolitan Area Network (MAN) Is a large computer network that usually spans a city or a large campus. - interconnects a number of LAN using a high- capacity backbone technology, such as fiber- optical links, provides up-link services to WAN and the Internet.

Metropolitan Area Network (MAN)

Wide Area Network Is a computer network that covers a large geographical area such as a city, country, or spans even intercontinental distances, using transmission facilities provided by a common carriers, such as telephone companies.

Wide Area Network

What is ?

Is a method of exchanging digital messages.

Address – is the location where messages can be sent to a user. -Consists of :  User Name  Internet Address separated by sign Ex.

What is Internet?

Internet Is called the network of networks because it is the largest collection of interconnected networks in the world.