- If the cable has three connectors, one of these connectors is attached to thedrive, one is a spare, and the third attaches to the primary or secondaryIDE connector on the system board.- If the cable has two connectors, one of these connectors is attached to thehard disk drive, and the other attaches to the primary or secondary IDEconnector on the system board.Note: If you want to add another device, and your computer does notcome with a CD-ROM preinstalled, you will need a second signalcable with three connectors. You will need an 80-conductor ATA 100signal cable if you are replacing the existing signal cable or adding asecond hard disk. ATA 100 signal cables are color-coded. The blueconnector attaches to the system board, the black connector attachesto the master device, and the gray middle connector attaches to thesecondary (or slave) device.If your computer comes with a CD-ROM drive, it will have an ATA100 signal cable. However, if you are installing a hard disk drive,you must change the switch or jumper setting on the CD-ROM driveto secondary and change the connector used for the CD-ROM driveto the gray middle connector.– The narrower signal cable has two connectors for attaching the diskette driveto the diskette-drive connector on the system board.Note: To locate connectors on the system board, see “Identifying parts on thesystem board” on page 22.The following are some important points to remember when connecting power andsignal cables to internal drives:v The drives that are preinstalled in your computer come with power and signalcables attached. If you replace any drives, it is important to remember whichcable is attached to which drive.v When you install a drive, ensure that the drive connector at the end of the signalcable is always connected to a drive; also, ensure that the drive connector at theother end is connected to the system board. This reduces electronic noise fromthe computer.v If two IDE devices are used on a single cable, one must be designated as theprimary or master device and the other as the secondary or slave device;otherwise, some of the IDE devices might not be recognized by the system. Theprimary or secondary designation is determined by switch or jumper settings oneach IDE device.v If two IDE devices are on a single cable, and only one is a hard disk drive, thehard disk drive must be set as the master device.v If you have only one IDE device on a cable, it must be set as master.For help in selecting drives, cables, and other options for your computer, see“Available options” on page 9.Installing internal drivesTo install an internal drive, following these steps.Note: If your computer has a CD-ROM drive, you might need to remove thesignal and power cables from the drive.1. Remove the cover (see “Removing the cover” on page 21).Chapter 3. Installing internal options — desktop model 29