Abstract: A helical-scan tape storage device is operative to write computer data to tape according to a predetermined format in which the data is store in tracks arranged in groups. These groups are optionally separated by one or more amble track To enable auxiliary data, such as audio data to be stored within the format, the storage device is arranged to store a succession of N ambles into which the auxiliary data is written. Using the amble tracks to store auxiliary data permits storage devices that have been designed only with regard to computer data storage to read tapes containing both computer and auxiliary data, since the auxiliary-data-containing amble tracks are ignored by such a device. A storage device designed to extract auxiliary data from ambles can readily recover the auxiliary data.