| 摘要 |
A tape drive including a drive motor; a take-up reel driven thereby; and a motor speed control system controlling the angular velocity of the drive motor for maintaining a substantially constant linear velocity of the tape as it is wound on the take-up reel, said control system comprising: a turns-counter counting the turns of tape as each is applied to the take-up reel; a presettable register; presetting means for presetting a predetermined number in said register at the beginning of a tape drive operation when the take-up reel is empty of tape; means for decrementing the register at a rate, with respect to the rate of application of turns onto the take-up reel, which is initially large during the application of a first predetermined number of turns, and which is subsequently reduced during the application of subsequent turns, to cause the contents of the presettable register to decrease in a non-linear manner with respect to the rate of increase in the number of turns applied to the take-up reel to approximate the non-linear relationship between the angular velocity of the drive motor and the diameter of tape on the take-up reel required to produce a substantially constant linear tape velocity; and motor control means controlling the angular velocity of the drive motor in accordance with the contents of the presettable register.
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