Systems and methods are disclosed for full utilization of a data path's dynamic range. In certain embodiments, an apparatus may comprise a circuit including a first filter to digitally filter and output a first signal, a second filter to digitally filter and output a second signal, a summing node, and a first adaptation circuit. The summing node combine the first signal and the second signal to generate a combined signal at a summing node output. The first adaptation circuit may be configured to receive the combined signal, and filter the first signal and the second signal to set a dynamic amplitude range of the combined signal at the summing node output by modifying a first coefficient of the first filter and a second coefficient of the second filter based on the combined signal.

An apparatus may include a circuit configured to generate, by an analog to digital converter (ADC), one or more ADC samples based on an input signal. The circuit may be further configured to generate a first estimated signal using a first channel pulse response estimation with a gain constraint based on the one or more ADC samples and generate a second estimated signal using a second channel pulse response estimation with a phase constraint based on the one or more ADC samples.

A sequence of symbols is generated to describe a set of write data, the symbols having a length of nT, where T is a channel clock rate and n is an integer over a predetermined range. Bi-directional write currents are applied to a write pole to record the sequence of symbols to a magnetic storage medium. The write pole has an effective footprint with a downtrack length of mT, where m is an integer. The write currents are switched between a first rail current and a second rail current for alternating symbols, the write currents further transitioning to an intermediate current value for at least one channel clock period for symbols longer than 1T. Write currents are applied to the write pole when recording symbols having a length longer than mT using the effective footprint of the write pole as an interval.

An apparatus may include a circuit configured to process at least one input signal using a set of channel parameters. The circuit may adapt, using a regularized adaptation algorithm, a first set of channel parameters for use by the circuit as the set of channel parameters in processing the at least one input signal, the regularized adaptation algorithm penalizing deviations by the first set of channel parameters from a corresponding predetermined second set of channel parameters. The circuit may then perform the processing of the at least one input signal using the first set of channel parameters as the set of channel parameters.

A sequence of symbols is generated to describe a set of write data, the symbols having a length of nT, where T is a channel clock rate and n is an integer over a predetermined range. Bi-directional write currents are applied to a write pole to record the sequence of symbols to a magnetic storage medium. The write pole has an effective footprint with a downtrack length of mT, where m is an integer. The write currents are switched between a first rail current and a second rail current for alternating symbols, the write currents further transitioning to an intermediate current value for at least one channel clock period for symbols longer than 1T. Write currents are applied to the write pole when recording symbols having a length longer than mT using the effective footprint of the write pole as an interval.

An apparatus according to one embodiment includes a hardware based controller that is configured to perform operations. The operations include performing anti-aliasing filtering on each of a plurality of signals, each signal having a frequency that is a different fraction of a frequency of a data read clock. An amplitude is measured of each of the signals after the anti-aliasing filtering. Moreover, the operations include determining whether the measured amplitudes of the signals are within a predefined range. Anti-aliasing settings used during the anti-aliasing filtering are stored in response to a determination that the amplitudes of the signals are within the predefined range. The anti-aliasing settings are changed in response to a determination that the amplitudes of the signals are outside the predefined range.

Systems and methods are disclosed for applying multi-stage multiple input single output (MISO) circuits for fast adaptation. An apparatus may comprise a first reader and a second reader configured to simultaneously read from a single track of a data storage medium, a MISO circuit. The MISO circuit may include a first stage filter having a first number of taps and configured to filter signal samples received from the first reader and the second reader and produce first filtered samples. The MISO circuit may also include a second stage filter having a second number of taps greater than the first number, and be configured to receive the first filtered samples corresponding to the first reader and the second reader from the first filter stage, filter the first filtered samples to produce second filtered samples, and combine the second filtered samples to produce a combined sample output.

A method of digitizing an audio track carried on an elongate recording medium, such as a movie film, includes transporting the recording medium containing the audio track past a reader to enable sequential reading of the audio track. The reading of the audio track generates an analog output signal. The method also includes sensing a rate of transportation of the recording medium, and sampling the analog output signal at a sampling rate determined on the basis of the sensed rate of transportation to digitize the analog output signal. A system for digitizing audio is also disclosed.

A method involves determining bit aspect ratios for interlaced tracks written to a magnetic recording medium. The interlaced tracks include top tracks that are written partially overlapping with bottom tracks. Isolated test tracks are written at first different bit aspect ratios to determine a top bit aspect ratio that achieves a first target areal density for the isolated test tracks. Test tracks are written at second different bit aspect ratios to determine a bottom bit aspect ratio that achieves a second target areal density for the test tracks. Top test tracks of the test tracks are written at the top bit aspect ratio. The top and bottom bit aspect ratios are selected to subsequently write partially-overlapping tracks on the magnetic recording medium.

An apparatus according to one embodiment includes a hardware based controller that is configured to perform operations. The operations include performing anti-aliasing filtering on each of a plurality of signals, each signal having a frequency that is a different fraction of a frequency of a data read clock. An amplitude is measured of each of the signals after the anti-aliasing filtering. Moreover, the operations include determining whether the measured amplitudes of the signals are within a predefined range. Anti-aliasing settings used during the anti-aliasing filtering are stored in response to a determination that the amplitudes of the signals are within the predefined range. The anti-aliasing settings are changed in response to a determination that the amplitudes of the signals are outside the predefined range.