Abstract: A method and apparatus for recovering analog signal information from a multiple-track information storage medium such as a magnetic tape is based upon time base error correction of a frequency modulated carrier signal. In one embodiment, the phase difference of a pair of pilot signals recorded on tracks adjacent a data track is compared by a sampling and pulse counting technique to eventually produce a trigger signal for a phase-locked oscillator. The output of the phase-locked oscillator is employed to sample and measure the period of the input data signal. The period values are written as digital values into a digital first-in first-out buffer memory. A stable clock is used to read out the contents of the buffer memory which are thereafter converted to a pulse rate modulated pulse train. The pulse train is converted to a useable analog signal by a pulse rate to frequency converter.

Abstract: Methods and apparatus for driving an information carrier tape use spaced distinct first and second capstans for arranging the tape in a U-shaped tape path having a pair of leg portions spaced from each other by the first capstan and extending to the second capstan and having a bight portion formed by the second capstan and interconnecting the leg portions. In one type of embodiments, the tape is driven with the first capstan and the tape is also driven with the second capstan independently of the first capstan. In another line of embodiments, one of the first and second capstans is electrically slaved to the other capstan.