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:
Jul. 30, 1991
Filed:
May. 12, 1988
Michael D Leis, Framingham, MA (US);
Bruce Leshay, Marlborough, MA (US);
Michael Muchnik, Framingham, MA (US);
Satish Rege, Groton, MA (US);
Charles M Riggle, Colorado Springs, CO (US);
Lih-Jyh Weng, Lexington, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A disk drive system provides all required synchronization, positioning, validation, and data functions within each disk sector. All of these functions are provided within two zones, a header section and a data section. The header section includes a preamble, a synchronization character and an address field, as well as servo information for track following. The data section of each sector includes a data preamble, a data synchronization character, a bad sector bit map, the data and data redundancy information. The header section of at least one sector in a track includes a short DC-erase field, a transitionless segment which is used in synchronization. To synchronize a read/write head to the disk, the system first detects the DC-erase field. The system next searches for the header premable and synchronization character. If it finds them within predetermined times, it then looks for a valid sector address to complete the synchronization. If the system does not detect the preamble and synchronization character within the predetermined times, it looks for another DC-erase field and continues the synchronization process. After the preamble and synchronization character are found, the desired sector is located by reading the addresses of the succeeding sectors.