Patent US3765005A successfully refreshed from Google Patents.
US3765005A
Expired / Lapsed
US
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Digital signal record systems
Assignee: International Business Machines Corp
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Filing: 1972-02-18
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Granted: 1973-10-09
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Expires: 1992-02-18
Abstract
Abstract A digital magnetic recorder uses up to twice the Nyquist bandwidth of a data signal, plus a clock signal at a frequency exactly equal to the bit rate for reliably exchanging data signals with a magnetic media. The frequency response of the recording system is greater than twice the Nyquist bandwidth of the data signals to be recorded. Optionally, additional control signals at frequencies above or below the clock frequency but within the available recorder bandwidth may be recorded. Preferably, in a multi-track magnetic recording system, a signal component is added at a frequency near the clock frequency such that the difference between this signal and the clock have a wavelength of the magnetic media greater than the maximum skew of the multi-track system. Such signal component is usable as a resynchronization pattern. Additionally, write errors are detected during recording with special control indicia recorded on the media indicating such errors. Without stopping the media, a write retry is effected in a predetermined relationship with the special indicia. Various forms of the indicia are described including special data patterns, special signal components, and the like. Special circuits established for handling data signals using framing techniques are described.
Inventors
- 👤 M Cannon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:51
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1883; G11B20/12; G11B20/1201; G11B20/1202; G11B20/14; G11B20/1403; G11B20/1407; G11B20/1419; G11B20/1816; G11B20/20; G11B5/00; G11B5/008; G11B5/00813; G11B5/00817; G11B5/02; G11B5/09; G11B2220/00; G11B2220/90; G11B5/48; G11B5/58; G11B5/584
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
105 words
A signal recording system for recording data-indicating signals on a magnetic media including the combination: means for recording data signals in a recorder channel having a predetermined frequency passband; means continuously establishing a control signal in a frequency portion of said recorder channel not occupied by said data signals and simultaneously supplying same to said recording means; means in operative association with said recording means for detecting quality of recording of said control signal; and repeat means responsive to a detection of apparent poor-quality recording of said control signal to automatically effect a rerecording of predetermined portions of said data signals in said data channel.
Claim 2
Dependent Claim
105 words
A signal recording system for recording data-indicating signals on a magnetic media including the combination: means for recording data signals in a recorder channel having a predetermined frequency passband; means continuously establishing a control signal in a frequency portion of said recorder channel not occupied by said data signals and simultaneously supplying same to said recording means; means in operative association with said recording means for detecting quality of recording of said control signal; and repeat means responsive to a detection of apparent poor-quality recording of said control signal to automatically effect a rerecording of predetermined portions of said data signals in said data channel.
Claim 3
Dependent Claim
73 words
The recording system set forth in claim 1 further including special indicia means responsive to a detection of poor-quality recording of said control signal to effect a recording of a special indicia on said magnetic media within said recorder channel in a predetermined relation to detection of said apparent poor-quality recording, and said re-recording having a predetermined geometric relationship on said magnetic media within said recorder channel with respect to said recorded indicia.
Claim 4
Dependent Claim
66 words
The recording system set forth in claim 2 wherein said special indicia means records said recorded indicia in predetermined frequency association with said control signal in the same recorder channel; and said predetermined association establishing a unique signal characteristic with respect to data signals recorded on said media in said same recorder channel which is different from any such characteristic recorded when said recording is satisfactory.
Claim 5
Dependent Claim
95 words
The recording system set forth in claim 1 wherein said data signals are recorded in a pass band of said recording system no greater than twice the Nyquist band of said data signals, and said control signal being recorded at the upper frequency of twice the Nyquist band of said data signals, all of said signals lying within a pass band of said recording system; and said means for generating said control signal establishing a fixed phase relationship between the data signals and said control signal and recording said control signal as a sine wave.
Claim 6
Dependent Claim
49 words
The signal recording system set forth in claim 4 further including signal component means recording signals in said track having predetermined frequency relationships with said control signal and outside said twice Nyquist bandwidth, said predetermined relationships having a preset indicating relationship to a given number of said data signals.
Claim 7
Dependent Claim
39 words
The signal recording system set forth in claim 5 wherein said signal component means includes a portion responsive to said repeat means to record some signal components having a fixed relationship to said re-recorded portions on said magnetic media.
Claim 8
Dependent Claim
53 words
The signal recording system of claim 1 further including data signal supplying means supplying data signals in a pass band substantially equal to twice the Nyquist bandwidth of said data signals and said establishing means supplying said control frequency at an integral multiple of a frequency in the center of said pass band.
Claim 9
Dependent Claim
126 words
A multitrack recording system wherein said media is subjected to a predetermined maximum skew; a plurality of recored tracks on said media; a separate single track recording system portion for each track consisting of the claim 7 subject matter; further including: framing means operatively connected to all said single track systems for supplying framing signals thereto having certain characteristics repeated at intervals not less than said predetermined maximum skew; and each said establishing means being individually responsive to said framing signal to introduce signal components into each said signal to be recorded exhibiting a predetermined phase relationship to said control signal said certain characteristics whereby frames of signals are independently indicated in each track in a fixed relationship to frames in each and every other track.
Claim 10
Dependent Claim
47 words
The multitrack recording system set forth in claim 8 wherein each said establishing means is further responsive to said repeat means to generate additional signal components for recording having a duration of about one frame for indicating a re-recording in each track receiving said additional signal components.
Claim 11
Dependent Claim
58 words
The multitrack system of claim 9 wherein said repeat means in any of said single track systems is responsive to any other repeat means effecting a re-recording to also re-record signals in frames identifiable with such re-recording in a track, but not record additional signal components unless an apparent poor-quality recording is detected thereby in the respective track.
Claim 12
Dependent Claim
61 words
An enhanced multichannel magnetic recording system, including the combination: a write circuit having write error detecting means operatively associated with each recording channel; and indicia means in each said write circuit responsive to a detected write error in its recording channel to magnetically record an error indicia in such channel associated with the write error without erasing the recording in error.
Claim 13
Dependent Claim
61 words
An enhanced multichannel magnetic recording system, including the combination: a write circuit having write error detecting means operatively associated with each recording channel; and indicia means in each said write circuit responsive to a detected write error in its recording channel to magnetically record an error indicia in such channel associated with the write error without erasing the recording in error.
Claim 14
Dependent Claim
43 words
The system set forth in claim 11 further including readback means; means for detecting said indicia; means for detecting data errors in signals in said readback means; and means combining said detected indicia and said data error detection to correct said data error.
Claim 15
Dependent Claim
52 words
The system set forth in claim 11 further including retry means in said write circuit responsive to said write error detecting means to simultaneously re-record signals associated with an indicated error and to cause said indicia means to record said error indicia in a frequency multiplexed manner in the channel in error.
Claim 16
Dependent Claim
57 words
ThE system set forth in claim 11 further including retry means responsive to said write error detecting means to re-record all signals in all channels substantially transversely aligned with said indicated write error at another location on said media and causing said indicia means to record in a manner to indicate said area having such re-recorded signals.
Claim 17
Dependent Claim
47 words
The system set forth in claim 14 wherein said write circuit records small numbers of signals in predetermined groups in each channel, and said indicia means establishing said error indicia for a length corresponding with a group length on said media in a group of rerecorded signals.
Claim 18
Dependent Claim
51 words
The system set forth in claim 15 further including group control means supplying group-indicating signals to said write circuit and said write circuit recording said group indicating signals in all channels along with other signals to be recorded but simultaneously recording said group-indicating signals in a like manner in all channels.
Claim 19
Dependent Claim
57 words
The system set forth in Claim 16 wherein said indicia means records said indicia in a frequency multiplexed manner only in those channels having an error indication for the duration of one of said groups and retry means simultaneously re-recording all signals in all channels with recording said error indicia in said channels having an error indication.
Claim 20
Dependent Claim
134 words
A multitrack magnetic recording system having a write circuit for supplying signals to be recorded for each track and means indicating a recording operation, transport means effecting relative motion between media and a transducer; data means supplying data signals to said write circuits; control means responsive to predetermined changes in said recording indication for indicating an undesirable recording operation and simultaneously causing said data means to resupply previously supplied data signals having a selected geometric relationship to said indicated undesirable recording operation, and said control means further operative without altering said relative motion in response to said indication to effect recording of said resupplied data signals a predetermined spacing from said supplied signals associated with said undesirable recording operation and to simultaneously record magnetic indicia in tracks giving rise to said undesirable recording operation.
Claim 21
Dependent Claim
134 words
A multitrack magnetic recording system having a write circuit for supplying signals to be recorded for each track and means indicating a recording operation, transport means effecting relative motion between media and a transducer; data means supplying data signals to said write circuits; control means responsive to predetermined changes in said recording indication for indicating an undesirable recording operation and simultaneously causing said data means to resupply previously supplied data signals having a selected geometric relationship to said indicated undesirable recording operation, and said control means further operative without altering said relative motion in response to said indication to effect recording of said resupplied data signals a predetermined spacing from said supplied signals associated with said undesirable recording operation and to simultaneously record magnetic indicia in tracks giving rise to said undesirable recording operation.
Claim 22
Dependent Claim
141 words
A magnetic recording system for recording digital-like signals on a magnetic media, the improvement including in combination: transducer means; transport means continuously effecting relative motion between said media and said transducer means for enabling transducing operations in one track along said media; write means for supplying signals to be recorded in said one track to said transducer means; and write retry means operatively associated with said write and transducer means for monitoring effective quality of the recording and responsive to certain monitored recording qualities to cause said write means to record error indicia on said media in said one track in preset relation to signals recorded during said certain quality monitoring and then to re-record such signals at another location in said one track on said media having a predetermined relation to said indicia, all without altering said transport means operation.
Claim 23
Dependent Claim
141 words
A magnetic recording system for recording digital-like signals on a magnetic media, the improvement including in combination: transducer means; transport means continuously effecting relative motion between said media and said transducer means for enabling transducing operations in one track along said media; write means for supplying signals to be recorded in said one track to said transducer means; and write retry means operatively associated with said write and transducer means for monitoring effective quality of the recording and responsive to certain monitored recording qualities to cause said write means to record error indicia on said media in said one track in preset relation to signals recorded during said certain quality monitoring and then to re-record such signals at another location in said one track on said media having a predetermined relation to said indicia, all without altering said transport means operation.
Claim 24
Dependent Claim
82 words
An enhanced magnetic recording system including the combination: signal processing means operatively associated with a magnetic media for exchanging data signals therewith along a given track in a given frequency bandwidth; and means monitoring said signal exchange and operative to magnetically record indicia on said media in said given track outside said given frequency bandwidth in response to a given characteristic occurring in said signal exchange and in predetermined geometric association with data-representing signals on said media associated with said given characteristic.
Claim 25
Dependent Claim
82 words
An enhanced magnetic recording system including the combination: signal processing means operatively associated with a magnetic media for exchanging data signals therewith along a given track in a given frequency bandwidth; and means monitoring said signal exchange and operative to magnetically record indicia on said media in said given track outside said given frequency bandwidth in response to a given characteristic occurring in said signal exchange and in predetermined geometric association with data-representing signals on said media associated with said given characteristic.
Claim 26
Dependent Claim
72 words
The magnetic recording system set forth in claim 20 wherein said signal processing means is a write circuit means foR recording signals on said media including means recording a constant energy signal of substantially constant frequency along with recording said data signals; and said monitoring means being frequency selective to monitor only said constant energy signal and responsive to amplitude perturbations in said energy to magnetically record indicia in said given track.
Claim 27
Dependent Claim
57 words
The magnetic recording system set forth in claim 21 including a plurality of independent signal processing means for a plurality of tracks and a like number of monitoring means for said respective tracks, respectively; and each said monitoring means operative to record indicia on the respective tracks for indicating a possible error condition in said respective tracks.
Claim 28
Dependent Claim
44 words
The magnetic recording system set forth in claim 22 further including means in said signal processing means responsive to an indicia recorded in any of said given tracks for re-recording all data signals associated with said given characteristics transversely with respect to said media.
Claim 29
Independent Claim
98 words
The method of operating a magnetic digital signal recording system including the following steps in combination for each record track: exchanging signals with a magnetic media; and monitoring the signal exchange for predetermined signal-exchanging characteristics and performing first functions on said signals being exchanged whenever said characteristics indicate a first signal exchanging status with respect to a given threshold and a second function on said signals being exchanged whenever said characteristic is in a second status with respect to said threshold and recording indicia on said media on said each record track indicating said second function was performed.
Claim 30
Independent Claim
98 words
The method of operating a magnetic digital signal recording system including the following steps in combination for each record track: exchanging signals with a magnetic media; and monitoring the signal exchange for predetermined signal-exchanging characteristics and performing first functions on said signals being exchanged whenever said characteristics indicate a first signal exchanging status with respect to a given threshold and a second function on said signals being exchanged whenever said characteristic is in a second status with respect to said threshold and recording indicia on said media on said each record track indicating said second function was performed.
Claim 31
Dependent Claim
50 words
The method set forth in claim 25 further including the steps of performing said second function including selecting signals having a predetermined relationship to said second status, then re-recording the selected signals within the same record track and in a frequency multiplexed manner with recording said indicia in such track.
Claim 32
Dependent Claim
43 words
The method of operating a multitrack recording system including the method set forth in claim 25 and further including the steps of performing each second function on all data signals in all tracks whenever such indicia is recorded in any of such tracks.
Claim 33
Dependent Claim
49 words
The method set forth in claim 26 further including the following steps: establishing error correction relationships with data signals exchanged with said media and modifying error correction in accordance with said indicia only with respect to data signal exchange with said media on said track associated with said indicia.
Claim 34
Independent Claim
68 words
The method of recording digital signals in transverse alignment across the media, including the following steps in combination: monitoring the quality of recording within sets of data signals transversely aligned across the media; and upon detection of predetermined faulty recording, recording special indicia on said media in said tracks and re-recording all signals on said media in such group in a predetermined geometric relationship to said recorded indicia.
Claim 35
Independent Claim
68 words
The method of recording digital signals in transverse alignment across the media, including the following steps in combination: monitoring the quality of recording within sets of data signals transversely aligned across the media; and upon detection of predetermined faulty recording, recording special indicia on said media in said tracks and re-recording all signals on said media in such group in a predetermined geometric relationship to said recorded indicia.
Claim 36
Dependent Claim
53 words
The method set forth in claim 28 further including the steps: recording said indicia only in those tracks giving rise to said predetermined faulty recording, but re-recording all signals in all tracks of such frame sets in such predetermined relationship and upon readback of said signals using the indicia as an error indicator.
Claim 37
Dependent Claim
91 words
The method set forth in claim 28 further limiting the pass band of data signals being exchanged to twice the Nyquist bandwidth of said data signals irrespective of the frequency response characteristic of said recording system; establishing a constant energy control signal at about the upper portion of said pass band for indicating timing relationships of data signals within the pass band in each of said tracks; and establishing further signal components above said twice Nyquist bandwidth indicatiNg intertrack relationships on a basis of data frames each having plural data signals.
Claim 38
Dependent Claim
44 words
The method set forth in claim 30 further including establishing said indicia in predetermined frequency relationship to said control signal but above said pass band for a period of time equal to processing one frame of said data signals in all of said tracks.
Claim 39
Dependent Claim
60 words
The method set forth in claim 31 further including a second constant-energy control signal having a difference frequency from said first control signal equal to the frequency of said data frames and establishing said difference frequency in a like manner in all of said tracks whereby transverse alignment of bytes of data recorded on said media can be readily identified.
Claim 40
Independent Claim
82 words
The method of operating a recording system including the steps of: processing electrical signals by exchanging such signals with a given record track on a record media and including performing electrical functions on such signals; monitoring said signal processing for evaluating selected characteristics exhibitable by said signal processing; and recording sensible indicia on said media in said record track whenever said selected characteristic is detected for indicating detection of such characteristic and continue exchanging such electrical signals while recording said sensible indicia.
Claim 41
Independent Claim
82 words
The method of operating a recording system including the steps of: processing electrical signals by exchanging such signals with a given record track on a record media and including performing electrical functions on such signals; monitoring said signal processing for evaluating selected characteristics exhibitable by said signal processing; and recording sensible indicia on said media in said record track whenever said selected characteristic is detected for indicating detection of such characteristic and continue exchanging such electrical signals while recording said sensible indicia.
Claim 42
Dependent Claim
183 words
A recording system for recording digital data signals, means for effecting relative motion between a transducer means and a single track on a record media, the improvement including in combination: a write circuit for supplying signals to the transducer means for recording on said single track; a read circuit for receiving signals from the transducer means indicative of signals recorded on said single track; a threshold circuit in the read circuit responsive to said received signals to indicate satisfactory or unsatisfactory recording; a digital signal source circuit including signal storage means for supplying digital signals to said write circuit; a control circuit in said source circuit and operative independent of the relative motion means and having retry means responsive to an unsatisfactory recording indication to effect a write retry by storing previously supplied digital signals in said source circuit storage means and resupply same from said storage means to said write circuit together with additional signals to be recorded in said track with said resupplied signals to point to said resupplied signals and said previously recorded signals resulting in said unsatisfactory recording indication.
Claim 43
Dependent Claim
183 words
A recording system for recording digital data signals, means for effecting relative motion between a transducer means and a single track on a record media, the improvement including in combination: a write circuit for supplying signals to the transducer means for recording on said single track; a read circuit for receiving signals from the transducer means indicative of signals recorded on said single track; a threshold circuit in the read circuit responsive to said received signals to indicate satisfactory or unsatisfactory recording; a digital signal source circuit including signal storage means for supplying digital signals to said write circuit; a control circuit in said source circuit and operative independent of the relative motion means and having retry means responsive to an unsatisfactory recording indication to effect a write retry by storing previously supplied digital signals in said source circuit storage means and resupply same from said storage means to said write circuit together with additional signals to be recorded in said track with said resupplied signals to point to said resupplied signals and said previously recorded signals resulting in said unsatisfactory recording indication.
Claim 44
Dependent Claim
73 words
The system set forth in claim 34 wherein said control circuit includes format means having counting means and for controlling said digital signal source circuit to group said digital signals into sets of signals and for indicating said sets, means generating said additional signals, and said retry means in said control circuit jointly responsive to said format means indicating a set of signals and an unsatisfactory recording indication to effect said write retry.
References Cited (Backward Citations)
US2937368A
Cited
US3369082A
Cited
US3559192A
Cited
US3490013A
Cited
US3550103A
Cited
US3686682A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |