Computer Architecture

Ports

Ports

There are lots of external devices that you can connect to your computer. All external devices connect to the computer’s system unit via cables and ports

A port is the slot into which you plug a cable that connects a peripheral to the computer.

Several external devices are attached to your computer already, including a mouse, keyboard, monitor, microphone, and speakers

Computer system and attached external devices

Examples of ports

Whatever external devices you have, they're all connected to the system unit via cables.

Each cable plugs into a specific port on the system unit.

The ports are usually on the back of the system unit. But they can be on front or side as well.

Examples of ports

More about ports

There are two traditional ports in use in all new PCs namely the COM port and the LPT port

COM Ports

Serial port most frequently used to connect a mouse or an external modem to your computer

Serial port used is usually RS 232C port

LPT Ports

A parallel port which is most frequently used to connect the PC to a printer

PS/2 Port

Most computers are equipped with a PS/2 port for connecting a mouse

The reason for the introduction of this port was that it freed up the serial port for other devices.

Universal Serial Bus (USB) Port

Serial port allowing up to 127 devices to be daisy chained to one port

Preferred method of connecting peripherals Speed of 12 MBps USB devices: screens, keyboards, mouse,

modems, printers, hard drives, flash drives, CD Writers, scanners, digital cameras, GPS, web cams

Built into most motherboards

USB 2.0

Improves USB speed and reliability further

Transfers data at 480 MBps Backward compatible with USB1 Compete with Firewire devices Improves speed of CD writers, hard

drives, digital still and video cameras

Plug and Play

Detects and configures a new device automatically without requiring a manual installation.

The computer must be rebooted before the operating system will detect the device.

Hot swappable/Hot plugging

An extension of plug and play Devices can be plugged in and out

while the computer is running and without having to reboot the computer

Devices can be added and removed while a computer is running

http://www.howstuffworks.com/usb.htm

http://computer.howstuffworks.com/firewire.htm

USB Hubs

A hub typically has four new ports, but may have many more. You plug the hub into your computer, and then plug your devices (or other hubs) into the hub. By chaining hubs together, you can build up dozens of available USB ports on a single computer.

USB and Firewire ports/logos

Firewire Serial communications standard Can connect up to 63 devices via a hub IEEE 1394 specification Allows transfer of data at high speeds up to

400 MBps. Latest version 800 MBps Becoming a standard on new PCs Features on most digital video cameras for

transfer of digital video for editing Other devices: external hard drives, CD writers

Wireless connection

Most common is called BLUETOOTH Wireless networking connection based on

very high frequency radio signals with a short range (10 – 15 meters)

Allows various electronic devices to talk to each other without physical connection

Without user intervention Through walls

Firewire

Edit & create custom video projects using fast hard drives, a digital camcorder and a computer.

Download video automatically with perfect digital clarity.

Content digital from start to finish – no loss of quality

AGP ( Advanced Graphic Port)

Faster video performance Single slot on a Pentium II, III and IV

motherboard for use with AGP graphic cards only AGP graphics cards can transfer data +_8 times

faster than a graphics card plugged into a PCI slot