Strata IT Training Chapter 3 Common Input/Output Devices

Basic I/O Devices Keyboard Mouse –USB –Wireless Monitor –CRT –LCD (Flat Screen)

Keyboards Key usage can depend on application –Games –Function keys QWERTY layout (first 6 letters of top row) –Originally designed to slow typing on manual typewriters Connectors –Mini-DIN or PS/2 (purple) –USB –Wireless

Keyboard Properties Open Control Panel Switch to Small icon view Click Keyboard –Change repeat delay and repeat rate –Change Cursor blink rate

Mouse Right-click –Get information Left-click –Select item Use Control Key and Shift key to select multiple –Double-click Advances to that selection Wheel –Scroll down window Middle-click –Wheel is also a button –Application dependent

Mouse Connectors Serial –Really old –9-pin connector PS/2 or Mini-DIN –Green plug USB – Type A Wireless –USB –Bluetooth Apple mice have one button

Changing Mouse Operations Open Control Panel Switch to Small icon view Click Mouse

Monitors CRT (Cathode Ray Tube) –Original monitor – Basically TV Set –Power Hungry –Dangerous high voltage 30,000 volt capacitors –Analog interface LCD (Liquid Crystal Display) –Flat Screen –Digital Interface –Lighter/Less Power –Wide aspect ratio

LCD Display Types Passive Matrix Each pixel must maintain its state passively, without being driven by circuitry. Lower cost Difficult to view at angle Active Matrix Each pixel is attached to a transistor and capacitor which actively maintain the pixel state while other pixels are being address Wider viewing angle More cost

Monitor Connectors Video Card or Motherboard –Video card for high speed gaming VGA –15-pin Analog -- CRTs DVI –Digital – LCD HDMI –TV and Computer video Devices may have multiple port types

DVI Connectors The DVI connector has up to 29 pins and is given one of three names, depending on which signals it implements: –DVI-D (digital only, single link or dual link) –DVI-A (analog only) –DVI-I (integrated, combines digital and analog in the same connector; digital may be single or dual link) –Dual link has 6 more pins for more bandwidth

HDMI Connectors Carry both audio and video signals Connector types: –Type – A –Type – B –Type - C

Monitor Properties Pixels –One point –Multiple color options require storage bits Resolution –Pixels across X pixels down –Higher resolution is clearer, but smaller

Resolutions

Aspect Ratios The ratio between number of pixels in height and width of screen The most common aspect ratios used today in the presentation of films in movie theaters are 1.85:1 and 2.39:1 –640x480 = 4:3 or 1.33 –1900x1080 = 16:9 or 1.77

Changing Monitor Properties Right-click desktop Left-click Personalize Click Display Click Adjust Resolution Set LCDs to max resolution for best (clearest) results Orientation If you have two monitors attached –Select Extend –Determine position

End of Chapter 3 Presentation