Patent ID: 7302605

Claim:
A method of fixing a faulty line or lines of operating code for delivery to a processor from a ROM contained in a location of said ROM designated by an address, said operating code being requested by said processor, comprising the steps of: providing a RAM having address locations, operating code locations associated with said address locations, and at least two flag bit locations associated with at least one of said address location; identifying said line or lines of said faulty operating code in said ROM; writing and storing correct line or lines of code in said RAM at said address location in RAM for each location of said faulty code in ROM starting at the first line of faulty code sequence and storing the address of said first line of faulty code in said RAM, setting a start flag at one flag bit location at said address of said correct code in said RAM; setting an end flag at said second flag bit location on the last line of correct code in said RAM; snooping said RAM for an address indicated by said start flag and, when found, delivering said correct code to said processor in place of said faulty code from said ROM until a line of code has an end bit flag; and returning to said ROM after said replacement code at said location of said detected end bit has been delivered.