Abstract: A magnetic disc storage system includes a rotating magnetic disc and a read/write transducer positioned proximate a recording surface of the magnetic disc for reading and writing information on the recording surface. Data stored on the recording surface is altered based upon the address of the data. During readback, a pseudorandom number generator receives a desired address as a seed input and provides a pseudorandom number output. An XOR gate provides an XOR output in response to the pseudorandom number output and the readback signal from the read/write transducer. An error detection circuit provides a decoded data output and an error flag output in response to the XOR output. An error during readback indicated by the error flag output is indicative of an incorrect address of the readback signal in comparison to the desired address. During a write operation, data is provided to an error detector encoder circuit which provides an encoded data output to an XOR gate.