PROCESS FOR REPLACING NON-VOLATILE MEMORY IN ELECTRONIC PRINTING SYSTEMS
 Inventors: Mark A. Smith, Rochester; Kitty Sathi, Pittsford; Jack T. Latone, Rochester, all of N.Y.
 Assignee: Xerox Corporation, Stamford, Conn.
 Appl. No.: 678,922
 Filed: Apr. 1,1991
 Int. CI.' G06F 11/00
 U.S. CI 395/575; 364/DIG. 2;
364/943.9; 364/944; 364/944.2; 364/944.5;
364/944.9; 371/8.1; 371/21.2
 Field of Search 395/575; 364/DIG. 2;
 References Cited
U.S. PATENT DOCUMENTS
4,499,581 2/1985 Miazga et al 371/20
Primary Examiner—Gareth D. Shaw
Assistant Examiner—A. Katbab
Attorney, Agent, or Firm—Frederick E. McMullen;
Gary B. Cohen
A method is provided for preserving the integrity of a memory in an electronic printer in the event that a printed wiring board with non-volatile memory is replaced. The memory includes plural disks providing permanent data storage and the non-volatile memory communicating with the disks. In the method, a processor identifier is provided with the printed wiring board. A time stamp indicating the date of installation of the printed wiring board is generated, and the processor identifier of the printed wiring board is combined with the time stamp to provide an identifier seal. Copies of the identifier seal are stored to each of the disks. The processor identifier of the printed wiring board is compared with the processor identifiers of the respective identifier seals of the disks in response to booting the processor. When the processor identifier on the printed wiring board is substantially different from one of the processor identifiers of the disks, the printed wiring board is replaced and the transfer of data between the non-volatile memory and the disks is inhibited until the processor identifier of the replaced wiring board and the processor identifiers of the disks correspond substantially.
10 Claims, 18 Drawing Sheets