摘要 |
A method and apparatus for increasing the throughput of memory disk drive quality control testing. The apparatus consists of a delay line for delaying the input signal from the read circuitry by one period of said input signal. A difference amplifier subtracts the delayed input signal from the undelayed input signal and couples the difference to one input of a comparator. The comparator compares the difference signal to a threshold used to indicate the presence of an "additional pulse". This test is performed simultaneously with a "missing pulse" test. The method involves delaying the input signal by one period and subtracting the delayed signal from the undelayed signal. A comparison of the difference to a predetermined threshold is then performed and where the threshold is exceeded, the corresponding location on the track under test is recorded as a probable defect. This method is performed simultaneously with a conventional method of performing a "missing pulse" test.
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