Apparatus for detecting any single bit error, detecting any two bit error, and detecting any three or four bit error in a group of four bits for a 25- or 64-bit data word

Granted: Feb 13, 1996 Filed: Jul 22, 1992

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.