Introduction to Computers

QUME 185

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Some objectives

define the term, computer, and discuss four basic computer operations

understand the terms hardware and software identify principal hardware components and

explain and their uses describe the use and handling of hard disks,

other disk types (e.g. CD-ROM) and other storage media (e.g. USB devices)

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More objectives

understand the difference between system software and application software

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Definition

A computer is an electronic device (or collection of devices), operating under the control of instructions stored in its own memory

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Capabilities

can accept data (input) manipulate the data according to

specified rules (process) produce information (output) from

the processing, and store the results for future use

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Four basic operations:The Information Processing Cycle

Input

Process

Output

Storage

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Hardware

Hardware refers to the physical components (devices) that make up a computer

This includes peripheral devices as well as internal components

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Modern computers

Speed Reliability: (low failure rate) Accuracy Storage capacity Communication: (a connected

device)

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Hardware components

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Parts of a system

Each device is associated with a phase of the information processing cycle

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Random access memory (RAM)

RAM (Random Access Memory) is the place in a computer where the operating system, application programs, and data in current use are kept so that they can be quickly reached by the computer's processor.

Much faster to access than data stored on hard drive

Data only stays in RAM only while the computer is turned on

1GB is now common

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Auxiliary storage

Hard disk (Usually internal but can be external)

CD/DVD disk (portable, removable and widely supported)

USB micro drives and similar devices

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CD-ROMs & DVDs

Metal storage medium that can hold large amounts of data.

CD ~ 650 MB DVD ~ 17 GB Removable, portable

& universal CD – ROM ~ read only CD-R ~ recordable CD-RW ~ re-writable

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Software

Software refers to the programs that give instructions to the computer carries out tasks for users Programs can be written in a variety of programming

languages such as Basic, C++, Java etc.

Two main types of software system software application software

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System software

Programs that control the operation of the computer

This includes the Operating System Many operating systems: Windows,

Macintosh, Linux, Unix See web page for key operating

system functions

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System software

Consists of programs to control the operations of computer equipment – especially the operating system (OS).

Instructions in the OS tell the computer how to perform the functions of loading, storing and executing applications software.

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Application software

Programs that perform specific tasks

There are thousands of different types of application software – for business, pleasure, scientific, educational and many other purposes

Word processing –creating all kinds of documents

Spreadsheet –performing calculations and financial projections

Presentation graphics –slides (like this)

Database –managing and retrieving data

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More application software

These are the main programs we work with in QUME 185

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File extensions

Each Windows application hasa native file format. Textbook, p 23

Format is indicated by a file extension. Examples: Word: .docx extension (older: .doc) Excel: .xlsx extension (older: .xls)

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File extensions can be made hidden or visible using the View tab of the Folder Options dialogue, available under the folder’s Tools menu

Extensions

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Help menu / About …

Help / About … in any software will display information about version number and ownership

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The Help Menu

If you need a quick answer, the Help menu usually provides the information

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Some ideas to think about

Future of desktop PCs and notebooks (other devices?)

A Few Trends:•VOIP•Music / movie downloads•News on demand ~ mobile devices ~ iPods •Podcasting•Blogging•Social networking ~ FaceBook ~ Wikis ~ Second Life•Google Maps / Google Earth• Cloud computing•Can you think of others?

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We can end here

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From data to information

Data: raw facts, figures, and symbols such as numbers, words, images, video and sounds

Information: data that are organized, meaningful and useful

Note: data is strictly speaking the plural of the word, datum

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Yellow Highlighting indicates some of the key differences

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Bad predictions – hard disk spacen 640K ought to be enough for anybody.

- Bill Gates, 1981

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Bad predictions – big iron

n Computers in the future may weigh no more than 1.5 tons.

-Popular Mechanics, forecasting the relentless march of science, 1949

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Bad predictions – market size

n "I think there is a world market for maybe five computers."

Thomas Watson, chairman of IBM, 1943

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Bad predictions – home computingn There is no reason anyone would want

a computer in their home.

Ken Olson, president, chairman and founder of Digital Equipment Corp., 1977

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Bad predictions – the microchip

n But what ... is it good for?

-engineer at the Advanced Computing Systems Division of IBM, 1968, commenting on the microchip

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Technology as a business drivern Hype

n Reality