| 摘要 |
A magnetic tape recording and reproducing arrangement comprising a rotary drum, helical scan digital video tape recorder including first and second head assemblies mounted diametrically on a rotary drum, the first head assembly including first and second heads having gaps of opposite azimuth angle, and third and fourth heads having gaps of opposite azimuth angle to the first and second heads respectively, the second head assembly including fifth and sixth heads having gaps of opposite azimuth angle, and seventh and eighth heads having gaps of opposite azimuth angle to the fifth and sixth heads respectively, tape guides to wrap a tape more than 180 DEG around the drum, in a recording operation the first head assembly through the first and second heads and the second head assembly through the fifth and sixth heads alternately recording pairs of skew tracks on the tape such that the tracks alternate in azimuth angle, and each of the first, second, fifth and sixth heads recording video data in a track for substantially but not exceeding 180 DEG of each complete rotation of the drum and vertical parity data in the track for some further part of each complete rotation of the drum, the further part lying wholly beyond 180 DEG , replay amplifiers to derive respective reproduced signals from all the heads, multiplexers to distribute the reproduced signals to four output channels, and a control arrangement including a programmable read-only memory to control the multiplexers in dependence on whether the selected reproduction mode is the normal mode, a slow shuttle mode or a fast shuttle mode.
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