Abstract: The scanning locus of a rotary head type recording and reproducing apparatus is evaluated by reproducing a tape having a number of oblique recording tracks. Respective track addresses are assigned to each track, and each track includes a number of block addresses. The track address and block address reproduced at a given time are supplied to an address map data storage device to generate in the address map data storage device a set of map information indicative of the scanning conditions of the rotary heads. This makes it possible to determine easily whether the reproducing conditions along the scanning locus with respect to the recording track are good or bad.