International Business Machines Corporation

Gary Lee Dix

Francis K King

Charles C Hanson

Robert Frederick Herald

Lloyd S Heim

William P Quinlan

Robin Charles Jahnke

Error information is passed across a limited interface from a disk drive to its using system by making use of the read data line during a fault mode operation. Fault mode operation is detected by a pulse width detector in an adapter between the using system and the disk drive. The pulse width detector detects the presence of a fault signal on the read data line and inhibits the passage of the spindle motor on (MTR ON) signal from the using system to the disk drive. The step signal normally used to index the recording head is passed to the disk drive during fault mode operation. A microcomputer at the disk drive detects the absence of the MTR ON signal and the presence of the step signal and outputs a fault data bit. Thereafter, the fault data word is gated onto the read data line at the rate of one bit per step of the step signal so long as the MTR ON signal is absent.

Method and apparatus for error data feedback in a diskette drive

A mechanism for moving an access arm carrying a magnetic transducer into the most appropriate position between pairs of consecutive flexible disks in a rotatable disk stack to assure that the proper disk is thereby accessed. The mechanism includes mechanism for preliminarily accessing each of the disks with a plurality of steps between consecutive disks in the stack and filling a position register with a unique identification number from each disk and with numbers of the steps corresponding to each of the disk numbers and mechanism for averaging the step numbers corresponding to each of the disks and placing the average step number in an access table to correspond with each of the disk numbers so that the access arm may be stepped to the step number listed for each of the disks in the access table for a reading or writing action using the transducer.

Flexible disk file access mechanism

Growing community of inventors

Rochester, MN, United States of America

Gary Lee Dix