PC Hardware in a Nutshell, Second Edition

Step 9: Connect Cables to the Motherboard

All systems require connecting various cables to the motherboard. These include:

• Cables that connect floppy, hard, and optical drives to embedded motherboard interfaces.

• Cables for miscellaneous functions, such as connecting audio out on the rear panel of a CD-ROM drive to the audio header on the motherboard, or connecting a CPU fan to a power header on the motherboard.

• Cables that connect front-panel switches (power, reset, keylock, etc.) and indicators (drive activity, power on, speaker, etc.).

• Supplementary case fans, which may connect to the motherboard or to power supply connectors.

It’s usually easier to connect these cables before you start installing expansion cards. Proceed as follows:

1. Connect the drive data cables from the back of each drive to the appropriate connector on the motherboard, making sure to align pin 1 properly on both the drive and controller. Typical systems have at least two such cables: a 34-wire ribbon cable connecting the floppy disk drive to the FDD controller interface on the motherboard, and an IDE cable connecting the hard drive and CD- or DVD-ROM drive to the primary IDE interface connector on the motherboard. If the system has more than two IDE devices, or if you put the hard drive and optical drive on separate channels, you will also need to connect a second IDE cable from the additional device(s) to the secondary IDE interface connector on the motherboard. If the system has SCSI devices installed and ...