公开(公告)号：CA1274623A

公开(公告)日：1990-09-25

申请号：CA535599

申请日：1987-04-27

Applicant: IBM

Inventor： CHRISTENSEN THOMAS C ,  COKER JONATHAN D ,  CUNNINGHAM EARL A ,  JAWORSKI RICHARD C ,  KERWIN GREGORY J ,  PALMER DEAN C ,  ROEPKE JEFFREY R

IPC: G11B5/09 ,  G11B5/00 ,  G11B5/012 ,  G11B5/035 ,  G11B5/455 ,  G11B20/18 ,  G11B27/36

Abstract: DISK DRIVE OPTIMIZED CHANNEL CIRCUIT A magnetic disk drive channel circuitry is shown and described that generates eight incremental values of write current and eight incremental values of delta-V (the minimum voltage change per unit time which tests signals to discriminate between data and noise). Each of these variable parameter values may be program selected by a three bit bus signal. This variability testing of and adaptation to the optimum parameter value for each head media combination and by grouping tracks in contiguous data bands, the parameters may be optimized for tracks near the inner diameter, the outer diameter and in the middle band. The variable delta-V can also be used as an additional data recovery tool wherein re-reading with a lower value enhances recovery of missing bit errors and re-reading with an increased value can assist recovery from an extra bit error.

公开(公告)号：BR8702794A

公开(公告)日：1988-03-01

申请号：BR8702794

申请日：1987-06-01

Applicant: IBM

Inventor： CHRISTENSEN THOMAS C ,  COKER JONATHAN D ,  CUNNINGHAM EARL A ,  JAWORSKI RICHARD C ,  KERWIN GREGORY J ,  PALMER DEAN C ,  ROEPKE JEFFREY R

IPC: G11B5/09 ,  G11B5/00 ,  G11B5/012 ,  G11B5/035 ,  G11B5/455 ,  G11B20/18 ,  G11B27/36

Abstract: A magnetic disk drive channel circuitry is shown and described that generates eight incremental values of write current and eight incremental values of delta-V (the minimum voltage change per unit time which tests signals to discriminate between data and noise). Each of these variable parameter values may be program selected by a three bit bus signal. This variability testing of and adaptation to the optimum parameter value for each head media combination and by grouping tracks in contiguous data bands, the parameters may be optimized for tracks near the inner diameter, the outer diameter and in the middle band. The variable delta-V can also be used as an additional data recovery tool wherein re-reading with a lower value enhances recovery of missing bit errors and re-reading with an increased value can assist recovery from an extra bit error.