Abstract: A magnetic recording system utilizing a plurality of surfaces on a magnetic recording disk with recording zone boundaries established on the respective surfaces of the disk based on the performance characteristic of the read/write head associated with the surface. Since the zone boundaries are established uniquely for the performance of each head rather than by defining the boundaries of all zones for all surfaces in advance based on an assumed performance characteristic of the heads, the zone boundaries on one surface of the disk will not necessarily align with the zone boundaries on another surface of the disk. Similarly, when a plurality of disks are utilized, the zone boundaries will not necessarily be aligned. Improved utilization of the available stroke on the disk drive permits further improvement in recording density.

Abstract: Rotary head recording and/or reproducing apparatus in which respective oblique tracks on a record medium are scanned, each track having an information signal area in which information data is recorded and a track following area in which a tracking control pilot signal is recorded. The track following area precedes the information signal area; and in the preferred embodiment, an additional track following area follows the information signal area. The pilot signal is recorded in only a portion of the track following area, the remainder of which has timing sync data recorded therein. In an after-recording mode the timing sync data is reproduced, detected and used as a reference to define an after-record area.

Abstract: In a magnetic recording and reproducing apparatus, a recording current setting circuit sets a recording current to be larger by 1 dB or more than a recording current which maximizes a reproduced signal level in correspondence to the shortest recording wavelength in digital signals to be recorded. Recording is performed with a magnetic head onto a metal powder tape including a magnetic layer of thickness having a 0.2 .mu.m or less. Thus, an overwrite characteristic can be obtained which are generally similar to that of a metal evaporation tape. Further, on reproduction, either an output from a equalizer circuit for a metal evaporation tape or an output from another equalizer circuit for a metal powder tape is selected by a switch circuit according to an output of a tape type detection circuit, and loop control gain of a tracking control circuit is changed according to the detected tape type. Thus, both metal powder tapes and metal evaporation tapes can be used.

Abstract: Write precomposition optimization for a partial response maximum likelihood ("PRME") magnetic recording chapel adapted to a mass production environment. Optimal write precompensation may be determined by writing a tribit data pattern known to produce worst case nonlinear transition shift ("NLTS") onto a magnetic recording medium; reading back the recorded data pattern; and calculating the mean-squared error ("MSE") for one or more of the equalized data sample levels associated with the PRML channel to be optimized. The writing and reading back process is repeated with varying amounts of precompensation applied to the written pattern. The optimal amount of write precompensation is determined eider by minimizing the MSE for a selected sample level or by minimizing MSE between the middle and the upper or lower of the ternary PRML sample levels.

Abstract: Disclosed is a circuit for detecting an unrecorded portion of a recording medium, which has a window counting portion (10) for receiving an input signal, for recognizing if the input signal comes from an unrecorded portion of the recording medium and for counting a predetermined time to generate a window signal. The circuit also has a sync signal generator (20) which is enabled by the window signal, in which, if the number of pulses of the input signal equals or exceeds a predetermined number, the generator recognizes that the current input signal comes from a data region of the recording medium and therefore generates a sync signal. If the number of pulses of the input signal is less than the predetermined number of pulses, the generator recognizes that the current input signal is due to noise from an unrecorded region of the recording medium, and therefore does not generate the sync signal.