Programmable execution control for magnetic disk control

摘要

The hard disk drive has two data disks (10) and four read-write heads (12). A pre-amplifier (14) amplifies the analog read signal from the heads and passes it to a read-write channel circuit (16) for recording on the discs during a write operation. The circuit decodes a data pulse in the signal for the disc data control (18). The disc data control (DDC) is provided with a running control for carrying the sequence of operations required according to a micro-program down-loaded by a micro-controller (22). It controls the read operation, passing data from the disks to the host computer, and a write operation, recording data from host computer on the disks. The DDC acts as an interface, storing data temporarily in the buffer RAM (20).