A
chip and associated circuitry that is responsible for controlling a
disk drive. There are different
controllers for different
interfaces. For example, an
IDE interface requires an IDE controller and a
SCSI interface requires a SCSI controller. On
Macintosh computer systems, the
disk controller is built into the
motherboard.
A controller for a hard disk is called a hard disk controller (HDC), and a controller for a floppy disk is called a floppy disk controller (FDC).