Patent ID: 7019930

Claim:
A read channel for reading magnetic data stored on a variable speed storage drive, comprising: said read channel being connected to a read head that is included in said variable speed storage drive; said read channel including an analog portion and a digital coupled together utilizing an analog-to-digital converter (ADC); said analog portion for receiving from said read head an input variable speed analog electronic data signal as its input and producing as its output an output analog signal, said analog portion not including an analog filter; said ADC receiving said output analog signal as its input and producing an output digital signal as its output; said digital portion including: a digital filter receiving as an input said output digital signal and producing as its output a filtered signal, said digital filter including a single set of filter coefficients that remain unchanged in response to a change in a rate of a variable rate clock; said variable rate clock being input into said digital filter; a digital decoding device being coupled to said digital filter, said decoding device including a pulse shaping filter coupled to a Viterbi detector; said digital decoding device receiving as its input said filtered signal; and said digital filter automatically adjusting to track a rate of said variable rate clock which automatically adjusts to track a rate of said variable speed analog electronic data signal.