Dell DCSM manual Inside View of Your Computer

		It is recommended that you use Category 5 wiring and connectors for
		your network. If you must use Category 3 wiring, force the network
		speed to 10 Mbps to ensure reliable operation.
3	network activity	Flashes a yellow light when the computer is transmitting or receiving
	light	network data. A high volume of network traffic may make this light
		appear to be in a steady "on" state.
4	surround	Use the black surround connector to attach multichannel-capable
	connector	speakers.
5	line-in connector	Use the blue line-in connector to attach a record/playback device such
		as a cassette player, CD player, or VCR.
		On computers with a sound card, use the connector on the card.
6	line-out	Use the green line-out connector (available on computers with
	connector	integrated sound) to attach headphones and most speakers with
		integrated amplifiers.
		On computers with a sound card, use the connector on the card.
7	micro-	Use the pink and silver connector to attach a personal computer
	phone/side	microphone for voice or musical input into a sound or telephony
	surround	program.
	connector	On computers with a sound card, the microphone connector is on the
		card.
		The side-surround output provides enhanced surround audio for
		computers with 7.1 speakers.
8	center/subwoofer	Use the yellow connector to attach a speaker to a Low Frequency Effects
	connector	(LFE) audio channel.
9	VGA video	If your monitor has a VGA connector, plug it into the VGA connector on
	connector	the computer.
10	USB 2.0	Use the back USB connectors for devices that typically remain
	connectors (5)	connected, such as printers, keyboards, and mice, or for bootable USB
		devices which may not function properly if attached to the front
		connectors (see "System Setup" for more information on booting to a
		USB device)

It is recommended that you use the front USB connectors for devices that you connect occasionally, such as joysticks or cameras.

Inside View of Your Computer

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.