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, 1991
Filed:
Oct. 23, 1987
David E Culler, Boston, MA (US);
Gregory M Papadopoulos, Arlington, MA (US);
Richard P Schneider, East Walpole, MA (US);
A.I. Architects, Inc., Cambridge, MA (US);
Abstract
An electronic device comprising a state machine is coupled between the ROM and its socket. When armed by an arming sequence, the device responds to an address from a microprocessor during a reset operation to modify the output of the ROM. The modified output causes a jump to a routine in RAM rather than a jump in an initialization routine in the ROM. This enables a user to change the microprocessor's addressing mode from protected to real without a complete initialization of the system. Arming of the device and reset of microprocessor is caused by a protected mode routine, and after reset the mircroprocessor processes a real mode routine.