US3997876A — Apparatus and method for avoiding defects in the …

Claim 1

Independent Claim 601 words

Apparatus for avoiding a defect in a data track on the recording media in a storage system, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon, in a recognizable position in each data track of the recording media, a control field defining the distance from a reference point on the recording media within that track to an end point, where the end point has a fixed spatial relationship to the defect affecting that track, the storage system having at least one transducer in operable transducing relationship with the recording media for recording information on or reading information from the recording media, the apparatus comprising: first means for generating, during a read or write operation for a record R(n), a value of the defect distance for the next sequential record R(n+1). the defect distance being defined from a constant fixed point within each record to said defined end point being used in conjunction with defects in the recording media; second means connected to said first means for storing the defect distance for record R(n+1), said second means' output providing as input to said first means; third means connected to said second means for generating an output signal when record R(n+1) is affected by a defect, said signal being generated at the beginning of a normal write operation of the storage system for recording record R(n+1); fourth means connected to said second means for controlling the transfer of the defect distance stored in said second means for recording the defect distance into the control field of record R(n+1) during the writing of the control field for record R(n+1) on the recording media by the storage system; fifth means connected to said second and said third means for controlling the interruption of the normal write operation of record R(n+1) and for the placement of a special gap onto the storage media during the interrupt period, said fifth means interrupting the normal write operation at an avoidance point with respect to record R(n+1) for preventing the defect from affecting the data being recorded with respect to record R(n+1) by placing the special gap about the defect on the recording media, the size of said special gap being greater than the maximum size of an allowable defect to be avoided by this apparatus and less than the distance B; sixth means responsive to the completion of the placement of the special gap for returning control to the storage system for continuation of the normal write operation for the completion of the recording of record R(n+1); seventh means for storing the defect distance recorded in a controlled field of each record when a record is read during a read operation, the output of said seventh means serving as an input to said first means during a read operation; eighth means connected to said seventh means for determining from the stored defect distance within said seventh means whether that record being read contains a special gap placed therein; ninth means connected to said seventh and eighth means for controlling the interruption of the normal read operation of the record being read at a time when said special gap will pass beneath the reading transducer of the storage system; and tenth means responsive to the end of the special gap passing beneath the transducer of the storage system for returning control to the storage system for continuing the normal read operation for completing the reading of said record.

Claim 2

Dependent Claim 601 words

Apparatus for avoiding a defect in a data track on the recording media in a storage system, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon, in a recognizable position in each data track of the recording media, a control field defining the distance from a reference point on the recording media within that track to an end point, where the end point has a fixed spatial relationship to the defect affecting that track, the storage system having at least one transducer in operable transducing relationship with the recording media for recording information on or reading information from the recording media, the apparatus comprising: first means for generating, during a read or write operation for a record R(n), a value of the defect distance for the next sequential record R(n+1). the defect distance being defined from a constant fixed point within each record to said defined end point being used in conjunction with defects in the recording media; second means connected to said first means for storing the defect distance for record R(n+1), said second means' output providing as input to said first means; third means connected to said second means for generating an output signal when record R(n+1) is affected by a defect, said signal being generated at the beginning of a normal write operation of the storage system for recording record R(n+1); fourth means connected to said second means for controlling the transfer of the defect distance stored in said second means for recording the defect distance into the control field of record R(n+1) during the writing of the control field for record R(n+1) on the recording media by the storage system; fifth means connected to said second and said third means for controlling the interruption of the normal write operation of record R(n+1) and for the placement of a special gap onto the storage media during the interrupt period, said fifth means interrupting the normal write operation at an avoidance point with respect to record R(n+1) for preventing the defect from affecting the data being recorded with respect to record R(n+1) by placing the special gap about the defect on the recording media, the size of said special gap being greater than the maximum size of an allowable defect to be avoided by this apparatus and less than the distance B; sixth means responsive to the completion of the placement of the special gap for returning control to the storage system for continuation of the normal write operation for the completion of the recording of record R(n+1); seventh means for storing the defect distance recorded in a controlled field of each record when a record is read during a read operation, the output of said seventh means serving as an input to said first means during a read operation; eighth means connected to said seventh means for determining from the stored defect distance within said seventh means whether that record being read contains a special gap placed therein; ninth means connected to said seventh and eighth means for controlling the interruption of the normal read operation of the record being read at a time when said special gap will pass beneath the reading transducer of the storage system; and tenth means responsive to the end of the special gap passing beneath the transducer of the storage system for returning control to the storage system for continuing the normal read operation for completing the reading of said record.

Claim 3

Dependent Claim 271 words

Apparatus for avoiding a defect in a data track on the recording media in a storage system during a read operation of the storage system, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon in a recognizable position in each data track of the recording media the distance from a reference point on the recording media within that track to an end point, where the end point has a fixed spatial relationship to the defect affecting that track, the storage system having at least one transducer in operable transducing relationship with the recording media for recording information on or reading information from the recording media, the apparatus comprising: first means for storing the defect distance recorded in a controlled field of each record when a record is read during a read operation; second means connected to said first means for determining from the stored defect distance within said first means whether that record being read contains a special gap recorded therein; third means connected to said first and second means for controlling the interruption of the normal read operation of the record being read at a time when said special gap will pass beneath the reading transducer of the storage system; and fourth means responsive to the end of the special gap passing beneath the transducer of the storage system for returning control to the storage system for continuing the normal read operation for completing the reading of said record.

Claim 4

Dependent Claim 271 words

Apparatus for avoiding a defect in a data track on the recording media in a storage system during a read operation of the storage system, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon in a recognizable position in each data track of the recording media the distance from a reference point on the recording media within that track to an end point, where the end point has a fixed spatial relationship to the defect affecting that track, the storage system having at least one transducer in operable transducing relationship with the recording media for recording information on or reading information from the recording media, the apparatus comprising: first means for storing the defect distance recorded in a controlled field of each record when a record is read during a read operation; second means connected to said first means for determining from the stored defect distance within said first means whether that record being read contains a special gap recorded therein; third means connected to said first and second means for controlling the interruption of the normal read operation of the record being read at a time when said special gap will pass beneath the reading transducer of the storage system; and fourth means responsive to the end of the special gap passing beneath the transducer of the storage system for returning control to the storage system for continuing the normal read operation for completing the reading of said record.

Claim 5

Dependent Claim 572 words

Apparatus for avoiding a defect in a data track on the recording media in a storage system, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon in a recognizable position in each data track of the recording media the distance from a reference point on the recording media within that track to an end point, where the end point has a fixed spatial relationship to the defect affecting that track, the storage system having a transducer for scanning said data track in operable transducing relationship, each record recorded being composed of two or more fields with gaps separating each field within a record and adjacent records, the first field in each record being a control field which contains a defect or skip displacement section, a flag section indicating which field, if any, is affected by a defect, and the length of each subsequent field in the record, said apparatus comprising: a first storage means for storing the control field of each record R(n) as that record R(n) is read by the storage system; decoding means for decoding the defect displacement section and the flag section of the control field for record R(n) stored in the first storage means so as to determine (1) if record R(n) contains a special gap B for defect avoidance and (2) when that special gap is specifically located in record R(n) if a special gap is written in record R(n); interrupting means connected to the first storage means and the decoding means for interrupting the normal read sequence for record R(n) during that period when the special gap passes beneath said transducer; a first defect distance generating means for generating a value for the defect distance for the next sequential record R(n+1), in anticipation that the operation for record R(n+1) will be a write operation; a second storage means for storing the generated value of the defect distance for record R(n+1); a third storage means for storing a control field for record R(n+1) during a write operation for record R(n+1); formatting means connected to the second and third storage means for determining if record R(n+1) will be affected during a write operation by a defect on the track, the formatting means generating proper values for the defect distance section and flag section of the control field for record R(n+1) such that the defect will not affect data recorded for record R(n+1); transfer means for transferring the generated value for the defect displacement section and flag section of the control field from the formatting means to the proper respective sections of the control field for record R(n+1) in the third storage means; second interrupting means connected to the formatting means for interrupting the write operation for record R(n+1) during the period so as to allow a special gap to be placed about the defect on the recording means so as to prevent information of record R(n+1) from being adversely affected by the defect; second defect distance generating means connected to the second means and the formatting means for generating a value for the defect distance for the next sequential record R(n+2) in anticipation that the operation for record R(n+2) will be a write operation, the generated value of the defect distance being stored in the second storage.

Claim 6

Dependent Claim 572 words

Apparatus for avoiding a defect in a data track on the recording media in a storage system, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon in a recognizable position in each data track of the recording media the distance from a reference point on the recording media within that track to an end point, where the end point has a fixed spatial relationship to the defect affecting that track, the storage system having a transducer for scanning said data track in operable transducing relationship, each record recorded being composed of two or more fields with gaps separating each field within a record and adjacent records, the first field in each record being a control field which contains a defect or skip displacement section, a flag section indicating which field, if any, is affected by a defect, and the length of each subsequent field in the record, said apparatus comprising: a first storage means for storing the control field of each record R(n) as that record R(n) is read by the storage system; decoding means for decoding the defect displacement section and the flag section of the control field for record R(n) stored in the first storage means so as to determine (1) if record R(n) contains a special gap B for defect avoidance and (2) when that special gap is specifically located in record R(n) if a special gap is written in record R(n); interrupting means connected to the first storage means and the decoding means for interrupting the normal read sequence for record R(n) during that period when the special gap passes beneath said transducer; a first defect distance generating means for generating a value for the defect distance for the next sequential record R(n+1), in anticipation that the operation for record R(n+1) will be a write operation; a second storage means for storing the generated value of the defect distance for record R(n+1); a third storage means for storing a control field for record R(n+1) during a write operation for record R(n+1); formatting means connected to the second and third storage means for determining if record R(n+1) will be affected during a write operation by a defect on the track, the formatting means generating proper values for the defect distance section and flag section of the control field for record R(n+1) such that the defect will not affect data recorded for record R(n+1); transfer means for transferring the generated value for the defect displacement section and flag section of the control field from the formatting means to the proper respective sections of the control field for record R(n+1) in the third storage means; second interrupting means connected to the formatting means for interrupting the write operation for record R(n+1) during the period so as to allow a special gap to be placed about the defect on the recording means so as to prevent information of record R(n+1) from being adversely affected by the defect; second defect distance generating means connected to the second means and the formatting means for generating a value for the defect distance for the next sequential record R(n+2) in anticipation that the operation for record R(n+2) will be a write operation, the generated value of the defect distance being stored in the second storage.

Claim 7

Dependent Claim 596 words

Apparatus for avoiding a defect in a data track on a recording media in a system which uses the count-key-data format, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon after index in each data track on the recording media, the distance from index on the recording media within that track to an endpoint where the endpoint has a fixed spatial relationship with the defect affecting that track, the storage system have a transducer for scanning said data track in operable transducing relationship with the recording media for recording information on and reading information from the recording media, the count field of each record being comprised of a defect or skip displacement section, a flag section indicating which field, the key or data field of record R(n) or the count field of record R(n+1), if any, is affected by a defect, the length of the key field, and the length of the data field, said apparatus comprising: a first storage means for storing the count field of each record R(n) as that record R(n) is read by the storage system; decoding means for decoding the defect displacement section and the flag section of the count field for record R(n) stored in the first storage means so as to determine (1) if record R(n) contains a special gap B for defect avoidance and (2) where that special gap is specifically located within record R(n) if a special gap is within R(n); interrupting means connected to the first storage means and the decoding means for interrupting the normal read sequence for record R(n) during the reading of the special gap by the transducer of the storage system; a first defect distance generating means for generating a value for the defect distance for the next sequential record R(n+1), in anticipation that the operation for record R(n+1) will be a write operation; a second storage means for storing the generated value of the defect distance for record R(n+1); a third storage means for storing a count field for record R(n+1) as received by the storage system from the record source for a write operation; formatting means connected to the second and third storage means for determining if record R(n+1) will be affected during the write operation by a defect on the track, the formatting means generating proper values for the defect distance section and flag section of the count field for record R(n+1) such that a special gap will be recorded about the defect if the defect affects record R(n+1); transfer means for transferring the generated value of the defect displacement section and flag section of the count field for record R(n+1) from the formatting means to the proper respective sections of the count field for record R(n+1) in the third storage means; second interrupting means connected to the formatting means for interrupting the write operation for record R(n+1) during the period so as to allow a special gap to be written about the defect on the recording means so as to prevent information of record R(n+1) from being adversely affected by the defect; second defect distance generating means connected to the second means in the formatting means for generating a value for the defect distance for the next sequential record R(n+2) in anticipation that the operation for record R(n+2) will be a write operation, the generated value of the defect distance being stored in the second storage means.

Claim 8

Dependent Claim 596 words

Apparatus for avoiding a defect in a data track on a recording media in a system which uses the count-key-data format, the recording media having an actual recording length L and a permissible data recording length of L-B, wherein B is a dedicated special gap, the recording media having been initialized prior to use with this apparatus to have recorded thereon after index in each data track on the recording media, the distance from index on the recording media within that track to an endpoint where the endpoint has a fixed spatial relationship with the defect affecting that track, the storage system have a transducer for scanning said data track in operable transducing relationship with the recording media for recording information on and reading information from the recording media, the count field of each record being comprised of a defect or skip displacement section, a flag section indicating which field, the key or data field of record R(n) or the count field of record R(n+1), if any, is affected by a defect, the length of the key field, and the length of the data field, said apparatus comprising: a first storage means for storing the count field of each record R(n) as that record R(n) is read by the storage system; decoding means for decoding the defect displacement section and the flag section of the count field for record R(n) stored in the first storage means so as to determine (1) if record R(n) contains a special gap B for defect avoidance and (2) where that special gap is specifically located within record R(n) if a special gap is within R(n); interrupting means connected to the first storage means and the decoding means for interrupting the normal read sequence for record R(n) during the reading of the special gap by the transducer of the storage system; a first defect distance generating means for generating a value for the defect distance for the next sequential record R(n+1), in anticipation that the operation for record R(n+1) will be a write operation; a second storage means for storing the generated value of the defect distance for record R(n+1); a third storage means for storing a count field for record R(n+1) as received by the storage system from the record source for a write operation; formatting means connected to the second and third storage means for determining if record R(n+1) will be affected during the write operation by a defect on the track, the formatting means generating proper values for the defect distance section and flag section of the count field for record R(n+1) such that a special gap will be recorded about the defect if the defect affects record R(n+1); transfer means for transferring the generated value of the defect displacement section and flag section of the count field for record R(n+1) from the formatting means to the proper respective sections of the count field for record R(n+1) in the third storage means; second interrupting means connected to the formatting means for interrupting the write operation for record R(n+1) during the period so as to allow a special gap to be written about the defect on the recording means so as to prevent information of record R(n+1) from being adversely affected by the defect; second defect distance generating means connected to the second means in the formatting means for generating a value for the defect distance for the next sequential record R(n+2) in anticipation that the operation for record R(n+2) will be a write operation, the generated value of the defect distance being stored in the second storage means.

Claim 9

Dependent Claim 426 words

The apparatus as set forth in claim 4 wherein the second interrupting means further comprises; decision means for determining whether a defect which would normally occur in either the key field or data field of record R(n + 1) will be most efficiently avoided by (1) the moving of the entire key or data field or (2) the dividing of the key or data field into two parts about the defect and recording between the divided parts the special gap, the decision means further determining if the count field for record R(r + 2) would be affected by the defect; the formatting means generating a value of the defect distance to be equal to zero and the flag bits associated with the key field, the data field of record R(n + 1) and the count field of record R(n + 2) respectively to be set to zero, where the defect has occurred prior to the writing of record R(n + 1); the formatting means generating a value of the defect displacement to be equal to zero and a value of 1 to be associated with the flag bit within the flag section to indicate which of the fields have been moved so as to avoid the defect; The formatting means setting the value of the defect displacement field to the value stored in the second storage means and setting all flag bits for the fields in the flag section to zero when the defect can affect subsequent records to record R(n + 1) but does not affect record R(n + 1) or the count field of record R(n + 2); the formatting means generating a value for the defect displacement section equal to the length of information to be recorded from the start of the key or data field to the start of the writing of the special gap and setting the flag bit associated with the key field or data field if the decision means has indicated the key or data field will be divided into two parts; the formatting means further comprising a remainder means for determining the value of the remaining portion of the key field or data field of record R(n + 1) to be written after the special gap has been written about the defect when the key or data field has been divided into two parts, the value generated by the remainder means being the data length remaining to be written by the storage system for record R(n + 1) upon the completion of the writing of the special gap.

Claim 10

Dependent Claim 119 words

In a system for writing variable-length records onto the tracks of a storage medium, each track being susceptible to a defect, the system comprising: means for writing a record Y onto a track; first means for determining the distance m available for record writing between a defect on the track to a reference point within a record X already written on the track; second means for ascertaining the length n of track necessary for writing record Y thereon; and third means responsive to signals from the first and second means for causing the writing means to suspend writing record Y along a portion of the track extent inclusive of the defect, if said signals indicate that m < n.

Claim 11

Dependent Claim 119 words

In a system for writing variable-length records onto the tracks of a storage medium, each track being susceptible to a defect, the system comprising: means for writing a record Y onto a track; first means for determining the distance m available for record writing between a defect on the track to a reference point within a record X already written on the track; second means for ascertaining the length n of track necessary for writing record Y thereon; and third means responsive to signals from the first and second means for causing the writing means to suspend writing record Y along a portion of the track extent inclusive of the defect, if said signals indicate that m < n.

Claim 12

Dependent Claim 126 words

In a system for writing variable-length records on a medium having recording tracks, each track of which is susceptible to having a defect disposed at a predetermined variable distance m available for record writing from a reference point on the track, the system comprising: means for writing a record Y on the track; first means for determining the predetermined distance m; second means for ascertaining the length n of the track necessary for writing record Y thereon; and third means for controlling the writing means responsive to signals from the first and second means for causing record Y to be written before the defect if m > n, after the defect if m = n and on either side of the defect if m < n.

Claim 13

Dependent Claim 126 words

In a system for writing variable-length records on a medium having recording tracks, each track of which is susceptible to having a defect disposed at a predetermined variable distance m available for record writing from a reference point on the track, the system comprising: means for writing a record Y on the track; first means for determining the predetermined distance m; second means for ascertaining the length n of the track necessary for writing record Y thereon; and third means for controlling the writing means responsive to signals from the first and second means for causing record Y to be written before the defect if m > n, after the defect if m = n and on either side of the defect if m < n.

Claim 14

Dependent Claim 33 words

In a system according to claim 7 wherein: the third means further includes means for causing the writing means to suspend writing along a portion of the track extent inclusive of the defect.

Claim 15

Independent Claim 112 words

A method for recording data records on a storage medium having at least one defective area disposed along a continuous data track comprising the steps of: recording data records along said data track; recording control information at the beginning of a data record in a special gap, said control information defining the distance from a reference point on said data track to a defective area existing along the track on which said record is to be recorded; and monitoring said control information during recording for recording at least one portion of said data record in a divided pattern, so that no part of said data record is registered over the defective area.

Claim 16

Independent Claim 112 words

A method for recording data records on a storage medium having at least one defective area disposed along a continuous data track comprising the steps of: recording data records along said data track; recording control information at the beginning of a data record in a special gap, said control information defining the distance from a reference point on said data track to a defective area existing along the track on which said record is to be recorded; and monitoring said control information during recording for recording at least one portion of said data record in a divided pattern, so that no part of said data record is registered over the defective area.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-12-14	1980-06-14	1980-12-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-12-14	1984-06-14	1984-12-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-12-14	1988-06-14	1988-12-14	$7700.00	Window Closed / Lapsed

Apparatus and method for avoiding defects in the recording medium within a peripheral storage system

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