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:
Nov. 03, 1981
Filed:
May. 14, 1979
Donald J Rathbun, Andover, MA (US);
David B O'Keefe, Westford, MA (US);
Honeywell Information Systems Inc., Waltham, MA (US);
Abstract
Digital data is recorded on the surface of a magnetic media such as a disk or diskette in the form of magnetic flux transitions identifying clock and data information in a modified frequency modulation (MFM) mode. A read head senses the flux transitions which are in turn converted to digital signals. A counter in the adapter starts to count when the adapter receives a digital signal. The count is transferred to a register and the counter presets when the adapter receives the next digital signal. The count is indicative of the time between the successive digital signals and should be representative of multiples of an integer. The count signals stored in the register address a read only memory whose output signals preset the counter to a value to compensate for the difference between the expected time and the actual time between the successive digital signals thereby reducing the read error rate.