Patent ID: 8196019

Claim:
A method for providing error correction coding to codeword headers in a data tape format, the data tape format defining a codeword quad having first and second codeword headers interleaved with first and second codeword pairs, each codeword header comprising N m-bit bytes c k =c 0 , c 1 , . . . , c N−2 , c N−1 wherein K bytes c 0 -c K−1 of the first and second headers in a codeword quad differ such that if one is known the other can be inferred, the method comprising: redefining each header byte c k as comprising two interleaved nibbles, e k , o k ; for each header, generating nibbles e K -e N−1 as a function of nibbles e 0 -e K−1 ; for each header, generating nibbles o K -o N−1 as a function of nibbles o 0 -o K−1 ; assembling a codeword quad with the redefined headers; and recording the codeword quad on a tape medium.