The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 20, 1996
Filed:
Jun. 21, 1994
Ellis Easley, Jr, Ft. Worth, TX (US);
Patricia Gray, Hurst, TX (US);
Johannes Suwandhaputra, Ft. Worth, TX (US);
Julie Wolf, Crowley, TX (US);
Tandy Corporation, Ft. Worth, TX (US);
Abstract
A method and apparatus for detecting diskette change is provided. A step pulse signal generated using the CPU is sent to the step pulse line of the disk drive, in addition to the normal step pulse signal which can be issued from the floppy disk controller. Thus, a step pulse can be issued directly by the CPU without using the FDC. By positioning the head in the outmost cylinder and issuing a step pulse, at a time when the direction signal indicates outward direction, the door-open status signal can be updated, without causing movement of the head. By preventing head movement in response to a step pulse, door-open status information is updated without undesirable effects of excessive head movement, drive spinning, head movement noise, constant illumination of the drive light or unnecessarily occupying the CPU or other components.