UPGRADING REPAIRING PCs

Cable key prevents
improperly plugging
it into the drive
IDE connector
Stripe on
interface cable
denotes Pin 1
Figure 4.1 Typical ATA (IDE) hard drive connectors.
Master and Slave Drives
As Figure 4.2 demonstrates, virtually every IDE drive interface is
designed to handle two drives with a single 40-pin interface cable.
Because the cable has no twist, unlike a typical 34-pin floppy interface
cable, jumper blocks must be used on each hard drive to distinguish
between the first (or master) drive on the cable and the
second (or slave) drive on the cable.
Most IDE drives can be configured with four possible settings:
• Master (single-drive), also called Single
• Master (dual-drive)
• Slave (dual-drive)
• Cable Select
4 3 2 1
Pin 1
Master and Slave Drives 95
Power cable
RED(+5V)
BLACK(Gnd)
BLACK(Gnd)
YELLOW(+12V)
For virtually all systems, the Cable Select setting can be ignored
because it must be used with a non-standard IDE cable. Thus, only
three settings are really used, as seen in Table 4.1.