A plurality of recording media combined integrally having a plurality of
recording surfaces; and a plurality sets of reading heads and writing
heads, combined integrally, provided for the respective ones of the
plurality of recording surfaces, are provided. Upon writing data on each
recording medium with the writing head provided therefor, a writing
position is controlled as a result of positioning information previously
provided on the recording media including the recording medium other than
the each recording medium being read with the reading heads provided
therefor.