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:
Feb. 17, 1987
Filed:
May. 16, 1983
Edward Gershenson, Worcester, MA (US);
Data General Corporation, Westboro, MA (US);
Abstract
Digital encoding and decoding apparatus for encoding data codes to produce disk codes and decoding disk codes to produce data codes. In the encoding and decoding operations performed by the apparatus, the output consists of a code and a state which are produced from a current input code, a next input code, and the state code produced by the last operation. The apparatus consists of a PROM and a state code register for retaining the state code produced by the last encoding or decoding operation. The registers in the prom contain two sets of code-status words. Each code-status word in one set contains a disk code and a state code which are the result of an encoding operation; each code-status word in the other set represents a data code and a state code which are the result of a decoding operation. The state code register receives the bits of the code-status word which contain the state code. In an encoding operation, the address inputs for the PROM consist of the state code retained in the state register, a signal indicating that an encoding operation is taking place, and the current and next data codes to be encoded. The register thus addressed by these inputs contains a code status word representing the result of the encoding operation. The decoding operation works similarly, except that the address inputs are the state code, bits of the current and next disk codes to be decoded, and a signal indicating that a decoding operation is taking place.