Abstract: An instruction set is executed from Read Only Memory (ROM). When a current instruction in the instruction set corresponds to a reserved patch memory block of ROM, a Random Access Memory (RAM) index and a ROM return address are loaded into a memory map, and a program counter is set to a first reserved ROM address. After jumping the program counter to the first reserved ROM address, the program counter is jumped to RAM based on the RAM index to execute a patch code, which includes at least one instruction to set the program counter to a second reserved ROM address. When the program counter equals the second reserved ROM address, the ROM return address is retrieved. Then the instruction set is executed from ROM based on the ROM return address.

Abstract: An instruction set is executed from Read Only Memory (ROM). When a current instruction in the instruction set corresponds to a reserved patch memory block of ROM, a Random Access Memory (RAM) index and a ROM return address are loaded into a memory map, and a program counter is set to a first reserved ROM address. After jumping the program counter to the first reserved ROM address, the program counter is jumped to RAM based on the RAM index to execute a patch code, which includes at least one instruction to set the program counter to a second reserved ROM address. When the program counter equals the second reserved ROM address, the ROM return address is retrieved. Then the instruction set is executed from ROM based on the ROM return address.

Abstract: A method of executing a program using a processor is implemented by executing a first main program segment stored in a ROM device until a first ROM instruction address, corresponding to one of a first sequence of ROM instructions, matches one of a plurality of a patch addresses stored in a patch register set. In response to this matching, a first patch program segment, stored in a RAM device, is executed.

Abstract: There is disclosed an apparatus for machining large diameter, thin-walled steel rings to precise tolerances. A ring of metal stock is placed within the jaws of a group of screw-type clamps located on a flat lathe faceplate. The clamps are evenly spaced around the ring of metal stock and each contains one or more pairs of opposing screws. The clamp screws are slowly advanced until the screws gently touch the inner surface and outer surface of the metal stock ring. The opposing screws are then gradually tightened until the ring of metal stock is locked in place. The equal and opposite forces exerted by the opposing screws hold the metal stock rigidly in place without inducing mechanical stresses in the ring that would otherwise warp the ring while it was mounted on the lathe faceplate.