Appeal No. 1995-3903 Page 10
Application No. 08/062,737
qualification area includes sector pulse pairs 254 and echo
pulse pairs 258 separated by three erase gaps 252, 256, and
260. Col. 18, ll. 11-14. A reliable sector marker is
achieved with the sector and echo pulse pairs in conjunction
with a timing controller 130. Id. at ll. 46-48.
The timing controller responds to signals read by the
transducer heads in qualification areas. It generates all the
timing signals needed to position the transducer heads.
Col. 10, ll. 64-68. The controller includes two counters, an
up counter and a down counter. Each counter counts-out a 512-
microsecond interval corresponding to the duration of each
sector. The counters are clocked by a 15-MHz system clock.
During system reset, the counters are set by a TRIGGER (TRIG)
pulse after the first of two consecutive sectors has been
read. Col. 14, ll. 12-20.
Upon arrival of the TRIG pulse, the up counter begins
counting. It continues to count until the next TRIG pulse is
received after the second of the two consecutive sectors has
been read. At this point, the count in the up counter is
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