Video 1.07 – Parts and Connectors

Serial Ports * Transmits data one bit at a time and are usually male * 9 – 25 pins
Parallel Ports * Transmits data 8 bits at a time and are usually female * 25 pins
Game Ports * Are usually female * 15 pins in two rows
Both parallel and game ports have been replaced by USB
Early Mice used a serial connector; Keyboards used 5 pin DIN connector
Modern mice and keyboards are either PS/2, USB, or wireless
NIC (Network Interface Card) * Converts parallel communication to serial * Uses RJ-45 connector
Modem
* Slowest possible way to connect to the internet * Connects to phone line * 56 Kbps * V.92 supports faster speeds * Converts analog to digital * Converts digital to analog * Uses RS-11 converter

Video

VGA * Analog interface * D type, 15 pin/3 rows

DVI * Digital Video Interface
CS-Video
* Round with 4 or 7 pins * Connects to TV
USB
* Univeral Serial Bus * Hot swappable * USB1 * Transmits at 12 Mbps * 3 meters * USB2 * 480 Mbps * 5 Meters * A-Connector * Larger, plugs into PC * B-Connector * Smaller, plugs into device * Narrow SCSI * 50 pin * Type A * Wide SCSI * 68 pin * Type B * IEEE 1394 – Firewire * Serial * Foot * Hot swappable * Used for streaming media * Expected to replace SCSI * Multimedia (color coded) * Earphones * Microphones * Speakers

Video 1.09 - Video

Types of Monitors * CRT – older, bigger model * LCD – newer, slimmer model
CRT
* Cathode Ray Tube * Similar to television screens
LCD
* Liquid Crystal Display * Uses TFT (Thin Film Transistor) * AKA Active Matrix * Backlighting through polarized panels
Monitor Specifications * Screen Size * Diagonal dimension of screen * Contrast Ratio * Ration of purest white to purest black * Bigger is better * 1000:1 > 600:1 > 400:1 * Refresh Rate (CRT) * Times per second CRT writes beam to screen * Higher number is better * Response Time (LCD) * Time needed to create new screen * Lower number is better * Interlacing (CRT) * Beam writes to alternating lines * Compensates for slower refresh rates * Dot Pitch (CRT) * Distance between phosphorescent dots * Pixel Pitch (LCD) * Addressable pixels on screen * Same as resolution * Resolution (both CRT and LCD) * Addressable points on screen

* CRT Resolution * Standard Resolutions * 640 x 480 * 800 x 600 * 1024 x 768 * Higher resolution = sharper picture * LCD Resolution * Fixed resolution * Native resolution * Resolution * Pixel pitch * Native Resolutions * XGA – 1024 x 768 * SXGA – 1280 x 1024 * UXGA – 1600 x 1200 * WUXGA – 1920 x 1200

How to Configure Resolution Settings * Right click the Desktop Select Properties Select Settings in the Display Properties box

How to Configure Second Monitor * Buy second video card * Check CMOS * Install second card * Install second monitor
Connectors
* Analog * 15 pin, 3 row, D-type * VGA connector * Digital * DVI * S-video port * TV
Video Buses * AGP Slot * PCI Express slot * Twice as fast as AGP

* Modern motherboards * Several PCI slots * AGP or PCI Express (noth both) * Second video card uses PCI slot
Video Cards * Buy reputable brand * More expensive * Better performance * Check bus type and speed * Faster is better * Check video RAM on card * More is better
Troubleshooting
* Wavy image or screenflicker * May be EMI * Electromagnetic interference * Common sources * Fluorescent lights * Audio speakers * Never open a CRT monitor case * CRT monitors contain capacitors * Capacitors contain an electrical charge * Discharge can kill

Video 1.11 - Printers Hardware

Types of Printers * Dot Matrix * Inject * Laser
Dot Matrix * An impact printer * Clusters of pins strike at inked ribbon * Used in printing multi-part forms * Tractor feed system * Slow and noisy * Paper jams
Inkjet
* Thermal bubble * Uses heat to force ink through a nozzle * Piezoelectric technology * Uses electrical charge to force ink through a nozzle * Requires a special paper * CYMB
Laser
* Electophotographic * Six steps in the laser printing process * Expensive to replace toner catridges

The Six Steps in Laser Printing * Cleaning – cleans toner from drum, leaves drum with neutral charge * Conditioning – applies -600 volts to drum * Writing – laser writes image to drum – image is -100 volts * Developing – toner is transferred to the image * Transferring – toner is transferred to positively charged paper * Fusing – rollers apply heat and pressure to melt toner onto page

Problems with Laser Printers * Totally white page * Paper is not retaining a strong positive charge * Totally black page * Drum is not retaining a strong negative change * Streaking to the page * Probably low toner * Flakey or brittle print on page * Fuser is not hot enough * Fuser is not applying enough pressure * Garbled text * Incorrect driver

Printer Interfaces * Printers can be connected by * 36 pin Centronics * 25 pin parallel * USB * SCSI * 802.11 * IrDA * Bluetooth
To install a printer – it is best to run the installation CD rather than allow Windows to detect the drivers
Improving Performance * Add more memory * Move or delete graphics * Lower the resolution
Printing without Spooling * Print job is stored in computer until printer is free * Computer cannot be used again until printing is complete
Printing with Spooling * Print job is stored in printer’s queue * Computer is immediately free
Spooling
* Sends the print job to the print queue * Stores the print job in memory * Frees the operating system for other activities
Queue
* A list of print jobs waiting to be printed * To Access, double-click printer icon