Disk Controller

• A disk controller is the interface between the computer system and the disk drive hardware.
• When a device wants to read from or write to a sector, it gives that command to the controller.
• The controller does the job, then attaches checksums to ensure that the data isn't corrupted.
• If data is corrupted, then the checksum is nearly guaranteed to fail. This ensures that the data is stored reliably.
• It also performs remapping of bad sectors.