Apparatus and method of averaging disk transfer rate including division

Abstract

A disc control apparatus handles an even number of disc-shaped recording mediums run in rotation at a constant angular velocity and to which addresses are accorded for incrementing from an inner disc rim side or from an outer disc rim side. The disc control apparatus effectuates data accessing with the disc-shaped recording mediums in terms of a pre-set block as a unit. The control apparatus includes an accessing control unit which effectuates data accessing on the block basis by addressing from the outer disc rim side for one of the disc-shaped recording mediums of the set while effecting data accessing on the block basis by addressing from the inner disc rim side for the other disc-shaped recording medium of the set. During data recording/reproduction, one of two contiguous blocks is recorded/reproduced on the disc-shaped recording medium accessed from the outer disc rim side while the other block is recorded/reproduced on the disc-shaped recording medium accessed from the inner disc rim side. That is, one of the disc-shaped recording mediums of a set is recorded/reproduced from the outer disc rim side, while the other disc-shaped recording medium of the set is recorded/reproduced from the inner disc rim side, thereby assuring a uniform accessing speed, that is an averaged data transfer rate.