Computer Devices

CRT Display

Keyboard

Mouse

“The Box”CD-ROM Drive

FloppyDiskDrive

History of Computers - Long, Long Ago

• beads on rods to count and calculate• still widely used in Asia!

History of Computers - Way Back When

• Slide Rule 1630• based on Napier’s rules for

logarithms• used until 1970s

In the Beginning

IBM PC - 1981

• IBM-Intel-Microsoft joint venture• First wide-selling personal

computer used in business• 8088 Microchip - 29,000 transistors– 4.77 Mhz processing speed

• 256 K RAM (Random Access Memory) standard

• One or two floppy disk drives

Apple Computers

• Founded 1977• Apple II released 1977– widely used in schools

• Macintosh (left)– released in 1984, Motorola 68000

Microchip processor– first commercial computer with

graphical user interface (GUI) and pointing device (mouse)

Mobile Computing

A computer………..

• Can only do 4 things – Accept input– Process input– Output data– Store data

Operating System

• Software – Instructions for Computer• Operating system is set of instructions loaded

each time a computer is started• Program is instructions loaded when needed

Input Devices

• “How to tell it what to do”• Allows the user to enter information into a

system, such as a computer

Output Devices

• How it shows you what it is doing”• Machines or devices capable of representing

Storage Devices

• “How it saves data and programs”• Devices that receive data and retain it for

subsequent retrieval.

Printer

• can print out information that is in the computer onto paper. By printing you create what is known as a 'hard copy'.

• There are different kinds of printers which vary in their speed and print quality.

Keyboard

• The Keyboard is the standard data input and operator control device for a computer.

• It consists of the standard QWERTY layout with a numeric keypad and additional function keys for control purposes.

Mouse

• As it moves across the desk, its movement is shown on the screen by a marker known as a 'cursor'.

• You will need to click the buttons at the top of the mouse to select an option.

Monitor

• Visual Display Units (VDU) or monitors are used to visually interface with the computer and are similar in appearance to a television.

• Visual Display Units display images and text which are made up of small blocks of colored light called pixels. The resolution of the screen improves as the number of pixels is increased. Most monitors have a 4:3 width to height ratio

Compact Disk (CD)

• A CD is an optical disk impressed with a series of spiral pits in a flat surface which can be read optically by laser.

• DVD stands for Digital Video Disk. DVDs have a much larger capacity for storage than CDs.

• CD-ROM stands for Compact Disk - Read Only Memory. CD-ROM disks cannot be burned or have anything saved on them.

• CD-RW and DVD-RW are disks that you can save or burn information onto as long as you have a drive that is burn capable. RW stands for Re-Writable.

• CDs and DVDs are a popular and cheap method for storage.

Speaker

• Computer speakers are external speakers. Computer speakers are usually a simplified stereo system without a radio or other media sources built in.

Joystick

• The joystick is a rotary lever. Similar to an aircraft's control stick, it enables you to move within the screen's environment, and is widely used in the computer games industry.

Touch Screen

• A Touch Sensitive Screen is a pointing device that enables the user to interact with the computer by touching the screen.

LCD Projector

• An LCD projector is a device for giving presentations generated on a computer. They are the modern equivalent to the slide projector and overhead projector used in the past.

• Imagery is provided by an attached computer or other video source such as a VCR, DVD, or a cable box.

Hard Drive

• The hard disk is a direct-access storage medium with a rigid magnetic disk.

• The data is stored as magnetized spots arranged in concentric circles (tracks) on the disk.

• Each track is divided into sectors.• The number of tracks and sectors on a disk is

known as its 'format'.

Light Pen

• A Light Pen is a pointing device shaped like a pen used to control a video display unit.

• The tip of the light pen contains a light-sensitive element which, when placed against the screen, detects the light from the screen enabling the computer to identify the location of the pen on the screen.

• Light pens have the advantage of 'drawing' directly onto the screen.

Floppy Disk

• A floppy disk is a thin magnetic-coated disk contained in a flexible or semi-rigid protective jacket.

• Data is stored in tracks and sectors. • Once data is stored on a floppy disk it can be

'write protected' by clicking a tab on the disk. This prevents any new data from being stored or any old data being erased.

Digital Camera

• Digital Cameras capture an image which is stored in memory within the camera. When the memory is full it can be erased and further images captured.

• The digital images can then be downloaded from the camera to a computer where they can be displayed, manipulated or printed

Barcode Scanners

• Bar codes are sets of parallel bars of varying thickness and separation that are read optically by transverse scanning.

• A barcode scanner reads bar codes and converts them into digital character code.

Earphones

• Earphones (also known as headphones, stereophones, or headsets) receive an electrical signal from a media player or receiver and use speakers placed in close proximity to the ears (hence the name earphone).

Webcam

• A real time camera whose images can be accessed using the Word Wide Web, Instant Messaging, or a PC video calling application.

Scanner

• Scanners allow information such as a photo or text to be input into a computer. Scanners can be flatbed or hand-held to scan a much smaller area.

• If text is to be scanned, you would use an Optical Character Recognition (OCR) program to recognize the printed text and then convert it to a digital text file that can be accessed using a computer.

Microphone

• This system accepts the spoken word as input data or commands.

• Human speech is very complex, involving emphasis and facial expressions. However, technology is coming closer to complete speech recognition every day and speech recognition software is being integrated into operating systems and other programs we use on a daily basis.

• Simple commands from one user can be used to control machines.

• In this way a paralyzed person can operate a wheelchair or control heating and lighting.

SMART Board

• Interactive whiteboard that is connected to a computer and a data projector. Once the computer image is projected on the board, the SMARTboard can be used as a computer. By just using your finger you can control the computer. This device can be considered both an input and output device.

USB Flash Drive

• USB flash drives are compact and easy-to-use flash memory data storage devices that plugs into the USB port.

• The term "USB flash drive" is a generic term used to describe these products without specifying a particular manufacturer.

Robot

• Robots are able to perform a variety of tasks as a result of executing instructions contained within a program.

• Robots in a business sense mean automated machines designed to perform mundane operations which require accuracy, such as assembling cars.

SD Cards

• An SD Card (Secure Digital Card) is an ultra small flash memory card designed to provide high-capacity memory in a small size.

• SD cards are used in many small portable devices such as digital video camcorders, digital cameras, handheld computers, audio players and mobile phones.

H: Drive

“Other” Computing