Magnetic recording and reproducing apparatus with means for increasing amount of information to be stored in a magnetic memory disk

摘要

A boosted-capacity magnetic recording and reproducing apparatus compatible with a host device to which is connectable a standard-capacity magnetic recording and reproducing apparatus wherein first annular recording tracks on a first magnetic disk are identified with respective serial track numbers designated by the host device, the boosted-capacity apparatus comprising: a second magnetic disk having second annular recording tracks each of which is equally divided into a plurality of sectoral tracks identified with respective sectoral track numbers which are equal to the serial track numbers; a disc drive for rotating the first disk at a speed equal to a rotating speed of the first disk divided by the number of division of each second annular track; a magnetic head; a detector generating an indexing signal when each of boundaries between the sectoral tracks passes a predetermined position during rotation of the second disk; a positioning device for positioning the magnetic head on one of the second annular tracks which includes the selected sectoral track identified with the sectoral track number equal to the serial track number designated by the host device; and a controller for recording or reproducing information on or from the selected sectoral track, based on the indexing signal.