Introduction to Introduction to ComputersComputers

Introduction to Introduction to ComputersComputers

Introduction to Computers

We are living in an information age dependent upon digital information. Digital information is electronic information, the result of computer processing. Every type of job relies upon getting information, using it, managing it, and relaying information to others. Computers enable the efficient processing and storage of

information.

Computers around us…Do not think of a computer merely as the machine with the keyboard and the mouse, although that might be true for some types of computers. Embedded computers may be inside your household appliances, the VCR, the automobile, planes, trains, powerplants, water purification plants, calculators, and even inside a few toys. These embedded computers are very small. They affect our lives each day. Why, even modern traffic lights operate with computers. They are all around us. Think of additional ways in which computers affect our lives each day.

What is a Computer?An electronic device that stores, retrieves, and processes data, and can be programmed with instructions. Acomputer is composed of hardware andsoftware, and can exist in a variety ofsizes and configurations.

Uses of ComputerPC at HomeCommon uses for the computer within the home

• Computer games• Working from Home• Banking from Home• Connecting to the Web

Uses of ComputerOffice ApplicationsStock Control

Stock control is ideal for automation and in many companies it is now completely computerized. The stock control system keeps track of the number of items in stock and can automatically order replacement items when required.

Accounts / PayrollIn most large organizations the accounts are maintained by a computerized system. Due to the repetitive nature of accounts a computer system is ideally suited to this task and accuracy is guaranteed.

Uses of ComputerAutomated Production Systems

Many car factories are almost completely automated and the cars are assembled by computer-controlled robots. This automation is becoming increasingly common throughout industry.

Design SystemsMany products are designed using CAD (Computer Aided Design) programs to produce exact specifications and detailed drawings on the computer before producing models of new products.

Uses of ComputerComputers in Daily Life• Accounts• Games• Educational• On-line banking• Smart ID cards• Supermarkets• Working from home (Tele-working)• Internet

Types of Computers• Supercomputers

– A computer that led the world in terms of processing capacity, particularly speed of calculation, at the time of its introduction. The term "Super Computing" was first used by New York World newspaper in 1920 to refer to large custom-built tabulators IBM

made for Columbia University.

Used for highly calculation-intensive tasksSupercomputers are used for highly

calculation-intensive tasks such as problems involving quantum mechanical physics, weather forecasting, climate research (including research into global warming), molecular modeling (computing the structures and properties of chemical compounds, biological macromolecules, polymers, and crystals), physical simulations (such as simulation of airplanes in wind tunnels, simulation of the detonation of nuclear weapons, and research into nuclear fusion), cryptanalysis, and the like. Major universities, military agencies and

scientific research laboratories are heavy users.

Mainframe ComputerMainframes (often colloquially referred to as Big Iron) are computers used mainly by large organizations for critical applications, typically bulk data processing such as census, industry and consumer statistics and financial transaction processing.Nearly all mainframes have the ability to run Nearly all mainframes have the ability to run

(or "host") multiple operating systems and (or "host") multiple operating systems and thereby operate not as a single computer but thereby operate not as a single computer but as a number of virtual machines. In this role, a as a number of virtual machines. In this role, a single mainframe can replace dozens or even single mainframe can replace dozens or even hundreds of smaller servers, reducing hundreds of smaller servers, reducing management and management and administrative administrative costs while providing greatly costs while providing greatly improved improved

scalability and reliability.scalability and reliability.

Mainframe Computer• A very large computer capable of supporting

hundreds, or even thousands, of users simultaneously.

• Mainframes are just below supercomputers. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program

faster than a mainframe.

MinicomputerMinicomputerMinicomputer (colloquially, (colloquially, minimini) )

is a term for a class of multi-user computers which is a term for a class of multi-user computers which make up the middle range of the computing make up the middle range of the computing spectrum, in between the largest multi-user systems spectrum, in between the largest multi-user systems (traditionally, mainframe computers) and the (traditionally, mainframe computers) and the smallest single-user systems (microcomputers or smallest single-user systems (microcomputers or personal computers)personal computers) Minicomputer is a Minicomputer is a multiprocessing system capable multiprocessing system capable of supporting from 4 to about of supporting from 4 to about 200 users simultaneously.200 users simultaneously.

Microcomputer• The term microcomputer is generally

synonymous with personal computer (PC), or a computer that depends on a microprocessor.

• A microcomputer (sometimes shortened to micro) is a computer with a microprocessor as its CPU.

• Another general characteristic of these computers is that they occupy physically small amounts of space.

Microcomputer• The microcomputer came after the

minicomputer, most notably replacing the many distinct components that made up the minicomputer's CPU with a single integrated microprocessor chip.

• Cheap and easy to use. Often used as stand-alone computers or in a network.

• May be connected to large mainframe computers within big companies.

Microcomputer Model

Floor Model

BriefcaseBriefcase

Microcomputer Model

Desktop NotebookLaptop

SubnotebookSubnotebook PalmtopPalmtop

COMPUTER SYSTEM

KEYBOARD

PROCESSOR

MONITOR

PRINTER

Storage devices

Computer SystemA computer system consists of three primary

units:

Input units – accept data

Processor unit – processes data by performing comparisons and calculations

Output units – present the results

Input DevicesData are facts, numbers and characters that are

entered into the computer via keyboard.

Other types of input devices are mouse, joystick, light pens, scanners, camera, etc.

Processor UnitTwo main parts:CPU – where the actual processing

takes place; andMain memory – where data are

stored. The contents of main memory can

be transferred to auxiliary storage devices such as hard disks, floppy diskettes, zip disks, compact disks, or USB flash disk.

Output Unit

After the data has been processed, the results are output in the form of useful information.

Output units such as monitors and printers make the result accessible for use by people.

Hardware ,Software & Peopleware

The term hardware refers to the physicalcomponents of your computer such as thesystem unit, mouse, keyboard, monitor etc.

The software is the instructions that makesthe computer work. Software is held eitheron your computers hard disk, CD-ROM,DVD or on a diskette (floppy disk) and isloaded (i.e. copied) from the disk into thecomputers RAM (Random Access Memory),as and when required.

Peopleware means the programmers, students, teachers and other users and/or operators of the computers.

Four Operations of a Computer System

1. Input - Home computers are microcomputers. Input is supplied to the microcomputer with the use of a keyboard, a mouse, or another input device. These input devices may be called peripheral devices.

2. Processing - Processing is done inside the computer in an area called the central processing unit (CPU). Processing is the conversion of input to output.

3. Storage refers to holding information somewhere. RAM, Random Access Memory, is short-term memory. It is volatile memory because the memory is automatically "erased" when the power is turned off or interrupted. The RAM

memory is located inside the computer case on the motherboard. A motherboard is not the keyboard.

Four Operations of a Computer

System The keyboard is what you type with. A motherboard holds RAM memory, electronic circuits and other computer parts including the central processing unit. ROM, Read-Only-Memory, is not volatile meaning the memory is still there when power is interrupted or turned off. When the computer is turned back on again, ROM memory is still in storage on the internal hard disk.

4. Output is the result of a computer process. Output may be viewed on a monitor screen, heard through speakers, printed on printers, and so forth. Output devices may be considered hardware and are also considered to be peripheral devices.

A Basic Computer "System"

• A computer system refers to the computer AND all of its equipment. Equipment like speakers, printer, keyboard, scanner, etc. is called peripheral equipment, sometimes shortened to "peripherals". The central processing unit (CPU) is considered to be "the computer". Without peripheral equipment (such as monitor, printer, speakers, etc.) for input and output the microcomputer (home computer) will not be able to do anything you find useful. Your computer system cannot help you type a letter unless you have some type of software (program) to do this. Most typing is handled by a "word processing" program. A software program for your computer can be purchased at stores such as Windows 7 or for free like UBUNTU or Linux.