| 摘要 |
<p>Apparatus and method for detecting short-term speed variations in a reel-to-reel tape drive for use with digital data, comprising counters (132) for generating time windows representing equal numbers of data bits read from the tape, further counters (135) for counting up during one window and down during the next, comparators (136, 137) for comparing the residual count of the up/down counters with preset limits and an error indicator (138, 134) for indicating the condition when the residual count exceeds the permitted bounds. The invention may be practised over a plurality of data tracks, in which case the apparatus includes means (139, 140) for indicating an overall error when an error has been detected on all tracks.</p> |
