IBM A20i 2255 User Manual Download

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Power and signal cables for internal drives

Your computer uses cables to connect integrated drive electronics (IDE) drives to the power
supply and to the system board. The following cables are provided:

•

Four-wire

power cables

connect most drives to the power supply. At the end of these

cables are plastic

connectors that attach to different drives; these connectors vary in size.

Also, certain power cables attach to the system board.

•

Flat

signal cables

, also called

ribbon cables

, connect IDE and diskette drives to the system

board.

There are two sizes of ribbon signal cables that come with your computer:

—

The wider signal cable has two or three connectors.

–

If the cable has three connectors, one of these connectors is attached to the drive,
one is a

spare, and the third is attached to the primary or secondary IDE

connector on the system board.

–

If the cable has two connectors, one of these connectors is attached to the hard
disk drive,

and the other is attached to the primary or secondary IDE connector on

the system board.

ote:

If you want to add another device, and your computer does not come with
a

standard CD-ROM, you will need a second signal cable with three

connectors. You will need an 80-conductor ATA 100 signal cable if you are
replacing the existing signal cable or adding a second hard disk drive.
ATA 100 signal cables are color-coded. The blue connector is attached to
the system board, the black connector is attached to the master device,
and the gray middle connector is attached to the secondary (or slave)
device.

If your computer comes with a CD-ROM drive, it has an ATA 100 signal
cable. However, if you are installing a hard disk drive, you must change
the switch or jumper setting on the CD-ROM drive to secondary and
change the connector that is used for the CD-ROM drive to the gray
middle connector.

—

The

narrower signal cable has two connectors for attaching the diskette drive to the

diskette-drive

connector on the system board.

Note:

To locate connectors on the system board, see

”Identifying parts on the system board”

on page 16

The following are some important points to remember when connecting power and signal
cables to internal drives:

•

The drives that are standard in your computer come with power and signal cables attached.
If you

replace any drives, it is important to remember which cable is attached to which

drive.

•

When you install a drive, ensure that the drive connector at the

end

of the signal cable is

always

connected to a drive; also, ensure that the drive connector at the other end is

connected to the system board. This reduces electronic noise from the computer.

•

two IDE devices are used on a single cable, one must be designated as the primary, or

master,

device and the other as the secondary, or slave, device; otherwise, some of the

IDE devices might not be recognized by the computer. The primary or secondary
designation is determined by switch or jumper settings on each IDE device.

•

If two IDE devices are on a single cable and only one is a hard disk drive, the hard disk
drive must be

set as the master device.

•

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 7