Alterable Patch Circuits for Read Only Storage
Original Publication Date: 1981-Mar-01
Included in the Prior Art Database: 2005-Feb-11
Incorrect data in the read-only storage (ROS) of a microprocessor syste is patched by detecting the addresses of data blocks to be changed, inhibiting the normal ROS, and outputting modified data from another memory. Both this other data memory and the address-detection memory are random-access (read/write) memory (RAM) loadable from an I/O bus of the microprocessor system.