Setting up Your Computer – Plugs
Now that we know what each socket on our computer is for, we'll have a look at the plugs which fit into them.
Here's the chart again:
| Standard Colour | Connection Functions | Connection Type |
|---|---|---|
| 1 | PS/2 mouse connection. | 6 pin mini-DIN |
| 2 | PS/2 keyboard connection. | 6 pin mini-DIN |
| 3 | USB ports. | USB Type A |
| 4 | FireWire or IEEE 1394. | IEEE 1394 |
| 5 | Parallel port for older printers. | 25 pin D |
| 6 | Serial port. Rarely used in modern PCs. | 9 pin D |
| 7 | Analogue VGA. For connecting your standard monitor (screen). | 15 pin VGA |
| 8 | DVI - digital video input. Use this for monitors with a digital connection. | DVI |
| 9 | S-Video for connecting to a TV. | 4 pin mini-DIN |
| 10 | Composite video. | RCA jack |
| 11 | Audio input. Not good quality audio. | 3.5 mm jack |
| 12 | Audio stereo output for main speakers or headphones. | 3.5 mm jack |
| 13 | Microphone audio input. | 3.5 mm jack |
| 14 | Audio output for rear speakers. | 3.5 mm jack |
| 15 | Audio output for right-to-left speaker. | 3.5 mm jack |
| 16 | S/PDIF digital audio output. | 3.5 mm jack |
| 17 | Game port / MIDI for a joystick. | 15 pin D |
| 18 | Ethernet connection. Connects to your network or high speed modem. | RJ-45 |
| 19 | Centre / sub-woofer | 3.5 mm jack |
PS2 mouse and keyboard plugs

- The first image is an older mouse plug which is not the standard green, newer mouse plugs are the same colour as the centre image.
- The centre image is an adaptor which you can use to plug a USB mouse into a PS2 socket. You may wish to do this if you don't have enough USB ports for all your devices.
- The image on the right is a standard mauve PS2 keyboard plug.
USB plugs
Although the standard colour for USB connectors is black, most cables and connectors come in grey, transparent, cream or beige.
- The first image above is a standard USB plug - this one happens to be on a mouse, but all USB plugs for plugging into the socket (usually called a port) on your computer are exactly the same shape.
- The centre image shows the two ends of a USB extension cable.
- The image on the right is a USB camera cable. This has a device plug smaller than the standard type B shown below.
- The images below show two ends of a USB cable for connecting a peripheral device such as a printer or a scanner.
