Sampling Algorithms for Evolving Datasets

A chassis is slidably provided with a circular-arc control slide bulging toward a rotary cylinder and having projections spaced apart from each other. Reel supports and a reel drive mechanism are arranged on the curving-in side of the slide. Disposed on the path of movement of the slide is a drive cam gear formed with cam grooves each extending from an outer peripheral opening toward its center. The slide is formed thereon with a toothed projection which meshes with the cam gear during a period after one of the projections is fitted in the corresponding cam groove and until the other projection is fitted in the corresponding cam groove. The slide is further formed with a cam groove having engaged therein a soft brake lever for giving a light load to the reel support in REV mode, a brake lever for lightly braking a capstan motor in SLOW mode, a tension regulator lever for lightly braking the reel support in FF/REW mode, and a withdrawing lever for withdrawing a magnetic tape from a cassette for loading to operate these levers.