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:
May. 21, 1985
Filed:
Jan. 05, 1983
Ian M Green, Buckie, GB;
EMI Limited, Hayes, GB;
Abstract
A computer generally includes a program storage device for storage in memory of program or other information. The software or program may be expensive to produce yet can be copied without undue difficulty from the storage device. This invention provides a program storage device which does not output an address, as part of an instruction, if it is an address within the device. The data output from a programmable read only memory (PROM) is output to a data modifier where in response to a controller it is changed to a dummy address for output. Information to reconstitute the address is held in a stack then when the dummy address returns the controller causes an offset adder to return the original address. Steps can be taken to deal appropriately with conditional instructions and relative instructions.