公开(公告)号：US3869714A

公开(公告)日：1975-03-04

申请号：US44986474

申请日：1974-03-11

Applicant: IBM

Inventor： SCHNEIDER RICHARD C ,  VIELE JR LAWRENCE

IPC: G11B5/09

CPC classification number: G11B5/09

Abstract: Discrete magnetization areas on a magnetizable medium are switched by a magnetic field formed by current pulses through a magnetic head winding having relatively slow leading edge risetimes. The current risetime may be derived from conventional voltage pulses by alternately gating positive and negative timing circuits which control current flow. Passive circuit elements may also control the leading and trailing edge timing.

Abstract translation: 可磁化介质上的离散磁化区域由电流脉冲形成的磁场切换通过具有相对较慢前沿时间的磁头绕组。 通过交替选通控制电流流动的正和负定时电路，可以从常规电压脉冲导出当前上升时间。 无源电路元件还可以控制前沿和后沿时序。

公开(公告)号：CA1042546A

公开(公告)日：1978-11-14

申请号：CA218277

申请日：1975-01-17

Applicant: IBM

Inventor： SCHNEIDER RICHARD C ,  VIELE LAWRENCE JR

IPC: G11B5/09

Abstract: METHOD AND APPARATUS FOR CONTROLLING THE RISETIME OF A DIGITAL MAGNETIC RECORDING WAVEFORM Discrete magnetization areas on a magnetizable medium are switched by a magnetic field formed by current pulses through a magnetic head winding having relatively slow leading edge risetimes. The current risetime may be derived from conventional voltage pulses by alternately gating positive and negative timing circuits which control current flow. Passive circuit elements may also control the leading and trailing edge timing.

公开(公告)号：FR2281009A1

公开(公告)日：1976-02-27

申请号：FR7512560

申请日：1975-04-16

Applicant: IBM

Inventor： SCHNEIDER RICHARD C

IPC: G11B5/035 ,  H03K5/12 ,  H03K5/18

Abstract: The derivative function performed by the magnetic read head is compensated by an integration function. The high frequency roll-off and phase distortion is compensated by a series of circuits having in LaPlace transforms a transfer function of the form (1+AS) (1-BS) where A and B are constants, and S is the frequency variable jw. Phase distortion in the read signal appears in the form of asymmetrical pulses. constant A and B in the above transfer function may be varied by varying circuit components in the equalization network to eliminate the asymmetry in the read signal. In particular, the function (1+AS) may be used to shape the trailing edge of the read signal pulse, while the function (1-BS) may be used to shape the leading edge of the read signal pulse.

公开(公告)号：CA2112452A1

公开(公告)日：1990-10-28

申请号：CA2112452

申请日：1989-10-02

Applicant: IBM

Inventor： KARP JAMES M ,  ROACH STEVEN W ,  SCHNEIDER RICHARD C ,  WEST STEPHEN C

IPC: G06F11/10

公开(公告)号：CA2000013C

公开(公告)日：1994-08-16

申请号：CA2000013

申请日：1989-10-02

Applicant: IBM

Inventor： KARP JAMES M ,  ROACH STEVEN W ,  SCHNEIDER RICHARD C ,  WEST STEPHEN C

IPC: G06F11/08 ,  G06F3/06 ,  G11B20/12 ,  G11B20/18 ,  G06F11/00

Abstract: A record medium, such as a magnetic tape, optical disk, magnetic disk, and the like stores data signals and error redundancy signals. Resynchronization signals are interleaved between the recorded signals such that the error redundancy signals are usable to correct signals recorded between such interposed resynchronization signals wherein no error redundancy signals are recorded. Error pointing redundancy signals are recorded between all of the resynchronization signals for pointing to signals in error for enhancing the error correction. Such error pointing signals can be cyclic redundancy check (CRC) signals. Controls for taking advantage of the above-described arrangement are also described. Reframing and clock synchronization controls are also disclosed.

公开(公告)号：CA1222057A

公开(公告)日：1987-05-19

申请号：CA481999

申请日：1985-05-21

Applicant: IBM

Inventor： ADLER ROY L ,  FRANASZEK PETER A ,  HASSNER MARTIN ,  SCHNEIDER RICHARD C

IPC: H03M7/14 ,  G06T9/00 ,  G11B20/14 ,  H03M5/14 ,  H03M13/23 ,  H04L25/497 ,  H03M7/46

Abstract: Method and apparatus is described for encoding and decoding a stream of randomly distributed binary bits representing digital data, including an encoder for encoding the data stream in to achieve a run length limited, partial response coding of the data stream; a first decoder for decoding an encoded data stream to recover a timing signal stream; a second decoder for decoding the encoded data stream to recover a stream of data signals from the encoded data stream.

公开(公告)号：FR2300387A1

公开(公告)日：1976-09-03

申请号：FR7540378

申请日：1975-12-23

Applicant: IBM

Inventor： DENT ROY F III ,  SCHNEIDER RICHARD C

IPC: H03M7/00 ,  G11B20/10 ,  G11B20/14 ,  H04L25/497 ,  G11B5/09 ,  H03K13/24

Abstract: Data signals are linearly recorded on a record medium as a sequence of discrete amplitude levels, each level occurring in a bit period. For each received data bit signal, a separate sequence of such levels is generated in accordance with a predetermined rule such that each separate sequence of levels extends over a predetermined number of data bit periods. All of the amplitude levels from a plurality of data bit signals occurring in each data bit period are summed together to provide a resultant amplitude to be recorded. Such resultant amplitude in each data bit period is linearly recorded on the record medium. Readback and detection of such recorded signals is accomplished by first recovering data bit signals by supplying the readback signals through a filter matched to the sequence (preferably a tapped delay line) for reconstituting the data bit signals. The reconstituted data bit signals are then detected using known data bit detection techniques. The techniques are also applicable to other types of digital channels.