Peripherals Input Devices o Input Devices include Keyboard

Peripherals

Input Devices o - Input Devices include: Keyboard Standard Mouse Microphone Touchpad Digital Camera Scanner Webcam

Keyboard o o Often referred to as QWERTY. The keyboard is continually ‘scanned’ to see if a key has been pressed. Each character has a ‘Scan’ Code. The Operating System translates this ‘Scan’ Code into ASCII code.

Mouse o o Movement across the desk moves the ball or light beam. This moves the cursor on the screen. The movements are sent via the interface to the Operating System. o Speed of operations can be set by user. o Possibility of Errors etc

Microphone o o o The purpose is to allow sound data to be input in to the computer. Natural sound is analogue and this must be changed into digital for the computer to make sense of it. The purposes of using a microphone and a computer together are increasing by the day.

Digital Camera o o o Like a conventional camera. Film has been replaced by an array of image sensors and a storage device. Data must be converted from Analogue into Digital data for the computer to make sense of this.

Scanner o An input device that allows graphical data to be captured on to a computer. o OCR – Optical Character Recognition - This Software comes with most scanners. - It enables the conversion of graphical representation of text into a word processing file, database, spreadsheet, or other text format.

Touchpad o Small touch sensitive pad used as a pointing device on some portable computers such as a Laptop.

Webcam o o o A digital camera attached to a computer. The webcam software turns the image into a normal graphic and uploads to to the web server. The image can be placed on any webpage.

Resolution o o o Related to images Refers to quality of images (Digital Cameras, Webcams, Scanners, and Monitors) Ex: A camera with a resolution of 2 Mega. Pixels will take a less accurate picture than a camera with a resolution of 5 Mega. Pixels

Speed of Data Transfer o Basically, how fast the transfer of data is between 2 or more peripherals. o Can be measured in Mbps(Megabits p/second) or MBps (Megabytes p/Second) o - Depends on many aspects: Type of connections (USB, Fire. Wire, etc) Image/File Size Computer Specifications RAM

Capacity o o o Backing storage such as Hard Drives Cache size Flash Cards, Disks, etc

Output Devices o CRT Monitor o LCD Monitor o Inkjet Printer o Laser Printer o Loudspeakers

Monitors o o o CRT monitors comprise a sealed glass tube An electron gun fires a tiny stream of electrons at the screen. The image is made by illuminating particles on the screen. LCD or TFT work by allowing different amounts of white light through an active filter Much more expensive than current CRT monitors

Printers o o Laser Printers – Faster than Inkjet Printers, More Expensive to buy but running costs are lower. Inkjet printers – Cheap to buy, more expensive to run (5 ppp compared to 1 ppp), Good for small jobs, creative uses, etc

Loudspeakers o o à à à More common nowadays due to advances in Music Technology. Inbuilt speakers Vs External Speakers Inbuilt = poor quality External = amplifiers, subwoofers, etc External = More expensive

Task o TASK: Use your copy of these slides to assist you with the following: - Pick an Input peripheral and an Output peripheral from the list given and investigate each device. These slides should give you a good starting point. - Put all the information into an MS Publisher document in the form of an advertising poster. Remember: The whole class will be getting a copy of these notes so make them informative!