1. CHAPTER 1 Installing and Supporting I/O Devices Suraya Alias

2. Basic Principles I/O Device ◦Internal – h/disk, cd drives, dvd drives ◦External – keyboard, monitor, scanner Can be connected using ports (USB), motherboard (serial) or ports from expansion card When supporting I/O devices, fundamental principles to remember; 1. Every I/O device is controlled by software 2. Refer to documentation when installing 3. Some devices need application software in order to function 4. Problems with device sometimes can be solved using driver’s update 5. Learning hardware I/O is like a moving target

3. Working with keyboard Ergonomic keyboard ◦Designed for safe and comfortable interactions between human beings and machine 4 methods to connect a keyboard 1) DIN connector 2) PS/2 connector (mini din) 3) USB4) Wireless connection

4. Mouse and pointing devices 1) Mouse ◦Wireless ◦With keypad Mouse technologies Wheel mouse Optical mouse 2) Trackball 3) Touchpad Methods of connecting a mouse 1)PS/2 mouse port 2)Mouse bus card 3)Serial port 4)USB port 5)Y connection 6)cordless

5. Special Input devices 1) Barcode reader 2) Fingerprint reader 3) Iris recognition reader Biometric device – input device that inputs biological data about a person. Which can be used to identify a person’s Fingerprint, eyes, voice, face and handwriting.

6. Terms & definition Resolution = the number of individual dots of color, known as pixels, contained on a display. ◦Images are formed by series of dots and pixels ◦Resolution is expressed by identifying the number of pixels on the horizontal axis (rows) and the number on the vertical axis (columns), such as 800x600. ◦Resolution is affected by a number of factors, including the size of the screen. Dot pitch = diagonal distance between two closest dots of the same color Refresh rate = how often an image is updated or redrawn on the monitor ◦Low refresh rate will cause the image to flicker and lead to eye strain Screen size / viewable size = diagonal length of a monitor’s viewing area (the smaller the better quality) Interlaced = refresh the monitor by painting alternate rows (odd and even) on the screen Contrast ratio = the contrast between true black and true white color on the screen (the higher the better)

7. Choosing Monitors CharacteristicsCRTLCD Screen sizeYY Refresh rateY InterlacedY Response TimeY Dot pitchY ResolutionYY Pixel PitchY Color QualityYY MultiscanY ConnectorsYY CharacteristicsCRTLCD Contrast ratioY Viewing AngleY Display typeYY BacklightingY 1) CRT 2) LCD

8. How Monitor Works CRT LCD CRT (Cathode Ray tube) is a large sealed glass tube inside the monitor. Tiny dots of phosphor material in Red, Green and Blue (RGB) combines to make up each pixel (dots of color). Inside the CRT, an electron beam moves back and forth across the back of the screen. This causes the dots to glow, producing an image Also known as Flat panel displays (FPDs). Liquid crystal display technology works by blocking light. Specifically, an LCD is made of two pieces of polarized glass (also called substrate) that contain a liquid crystal material between them. A backlight creates light that passes through the first substrate. At the same time, electrical currents cause the liquid crystal molecules to align to allow varying levels of light to pass through to the second substrate and create the colors and images that you see.

9. Video cards A video card is rated by the bus it uses and the amount of video RAM on the card. Both features affects the overall speed and performance of the card Buses used by video cards 1)VESA bus – (Video Electronics Standard Association), internal bus that was developed for faster connection between the devices and processor 2)PCI bus – (Peripheral Component Interconnect) is a local bus that was developed by Intel for better integration between of data such audio and video 3)AGP bus – (Accelerated Graphic Port) is a bus that directly access the RAM that will improve the graphic display 4)New PCI Express bus – newer bus and faster bus to replace the old AGP and PCI, used in faster CPU

10. Video Memory Types of video memory 1) VRAM (Video RAM) 2) SGRAM (Synchronous Graphic RAM) 3) WRAM (Window RAM) 4) 3-D RAM (3D) 5) MDRAM (Multibank DRAM) 6) G-DDR (Graphic Double data rate ) 7) DRDRAM (Direct Rambus DRAM)

11. Using Ports, Expansion Slots Most computers provide one or more USB ports, one parallel port, IEEE 1394 (Firewire) port or serial port to be used for a variety of devices

12. Using Ports, Expansion Slots Three types of parallel ports are ; 1.Standard Parallel Port (SPP) – old printer port (data flow in one direction 2.EPP – Enhanced Parallel Port, data flow in two direction 3.ECP – Extended Capabilities Port (uses DMA – direct memory access channel) USB ports (Universal serial ports) is the easiest port to configure Serial ports are sometimes configures as COM1, COM2,COM3 or COM4 Parallel ports are configures as LPT1, LPT2 or LPT3 The IEEE 1394 bus provides, 4, 6 or 9 pin connectors