US3774154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Error control circuits and methods
Assignee: International Business Machines Corp
•
Filing: 1972-08-21
•
Granted: 1973-11-20
•
Expires: 1992-08-21
Abstract
Abstract A digital magnetic recording system or a signal transmission system employs an error detection and correction code capable of correcting k+n error conditions (k and n are positive integers) whenever quality signals point to an error-prone condition. Such error correction code can detect and correct k errors without pointers in a given set of data signals. At the transmitter, or during a recording operation, the recording of signal transfer is monitored. In addition, signals are recovered and processed through error detection and correction circuits for pointing to said k error conditions. Such k error conditions are then compared with the error-prone condition signals. An okay signal is provided if there are no errors or if there are k error conditions wherein the error locations within a set of data signals are pointed to both by the error-prone condition signals and the error correction code. An error condition exists if there are k+n (k 1 or more) or more errors or if the comparison for k error conditions is not met.
Inventors
- 👤 E Devore
- 👤 P Hall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:42
CPC Classifications
G; G11; G11B; G11B20/00; G11B20/10; G11B20/18; G11B20/1833; G06; G06K; G06K5/00
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
176 words
An error-control circuit for a digital recorder for verifying a magnetic recording operation, first means for recording digital signals on a magnetic record member identifiable in signal sets including error detection and correction code and data-representing signals; second means for recovering signals in a read-after-write operation just recorded on said record member by said first means; detection means for converting said read-after-write recovered signals to detected digital information-representing Signals; the improvement including in combination: error detection means capable of correcting k+n errors and receiving said detected signals for detecting errors therein, and either indicating no errors, k errors and locations thereof, or k+1 or more errors in each said set, wherein k and n are nonzero integers; quality signal means for detecting and indicating error-prone signal conditions in each said respective set; and comparison means jointly responsive to said error detection means and said quality signal means to indicate a recording error for k+1 or more detected errors or a non-comparision of said k error locations and said error-prone signal conditions and otherwise indicating acceptable recording.
Claim 2
Dependent Claim
176 words
An error-control circuit for a digital recorder for verifying a magnetic recording operation, first means for recording digital signals on a magnetic record member identifiable in signal sets including error detection and correction code and data-representing signals; second means for recovering signals in a read-after-write operation just recorded on said record member by said first means; detection means for converting said read-after-write recovered signals to detected digital information-representing Signals; the improvement including in combination: error detection means capable of correcting k+n errors and receiving said detected signals for detecting errors therein, and either indicating no errors, k errors and locations thereof, or k+1 or more errors in each said set, wherein k and n are nonzero integers; quality signal means for detecting and indicating error-prone signal conditions in each said respective set; and comparison means jointly responsive to said error detection means and said quality signal means to indicate a recording error for k+1 or more detected errors or a non-comparision of said k error locations and said error-prone signal conditions and otherwise indicating acceptable recording.
Claim 3
Dependent Claim
120 words
The error-control circuit set forth in claim 1 wherein said digital recorder is a multitrack digital magnetic recorder system having each said signal set recorded in all tracks, each record track receiving a signal subset from each respective said signal set; said quality signal means operating with each of said record tracks for indicating error-prone signal conditions in the respective record tracks (subset), one error-prone signal indication for each subset; said error detection means supplying an ECC error pointer, one pointer corresponding to each said tracks; and said comparison means comparing the track pointers from said error detection means and said quality signal means to indicate acceptable or unacceptable recording with said unacceptable recording including error correctable recorded signal conditions.
Claim 4
Dependent Claim
46 words
The error-control circuit of claim 2 wherein said quality signal means further includes means monitoring said recovered signals and means monitoring data combinations of said recovered signals, and further including means combining said indications to indicate an error-prone signal condition from either of said monitoring means.
Claim 5
Dependent Claim
48 words
The error-control circuit of claim 2 wherein said comparison means compares said ECC error pointer and said error-prone signal indicator on a concurrent time basis for permitting such error-prone signal indications to become active at times other than said ECC error pointer without causing an unacceptable recording indication.
Claim 6
Dependent Claim
107 words
A signal condition indicator comprising: means for receiving signals and segregating said signals into sets and subsets; means for detecting information signals from said received signals; error detection means responsive to said detected signals to indicate error conditions in said sets and, when a limited number of error conditions is detected, indicating errors occurring in particular ones of said subsets; means for monitoring said received signals and for indicating error-prone signal conditions in the respective subsets and supplying indications thereof; and comparison means jointly responsive to said error detection means and said monitoring means indicating different subsets in error to indicate an improper reception of received signals.
Claim 7
Dependent Claim
107 words
A signal condition indicator comprising: means for receiving signals and segregating said signals into sets and subsets; means for detecting information signals from said received signals; error detection means responsive to said detected signals to indicate error conditions in said sets and, when a limited number of error conditions is detected, indicating errors occurring in particular ones of said subsets; means for monitoring said received signals and for indicating error-prone signal conditions in the respective subsets and supplying indications thereof; and comparison means jointly responsive to said error detection means and said monitoring means indicating different subsets in error to indicate an improper reception of received signals.
Claim 8
Dependent Claim
72 words
The indicator set forth in claim 5 further including AND means receiving said comparison means indicator signal of received signals; said error detection means indicating whether or not fewer than k signal subsets are in error, where k is an integer greater than one; and said AND means being jointly responsive to said received signal error indicator signal indicating different subsets in error or k or greater errors to indicate an error.
Claim 9
Independent Claim
122 words
The method of recording signals on a magnetic media; dividing said signals into sets and subsets with each set of signals having error detection and correction code bits; recording signals on a record member; verifying the quality of the signals being recorded as exceeding a certain threshold by indicating a possible signal error condition for each of the respective subsets not reaching said threshold; comparing the data signals with the error detection and correction code bits as recorded; and comparing said signal error pointers with said error detection for indicating unsatisfactory recording has occurred requiring a rerecording whenever there is a predetermined lack of comparison and satisfactory recording not requiring a rerecording when such comparison matches even though there are error conditions.
Claim 10
Independent Claim
122 words
The method of recording signals on a magnetic media; dividing said signals into sets and subsets with each set of signals having error detection and correction code bits; recording signals on a record member; verifying the quality of the signals being recorded as exceeding a certain threshold by indicating a possible signal error condition for each of the respective subsets not reaching said threshold; comparing the data signals with the error detection and correction code bits as recorded; and comparing said signal error pointers with said error detection for indicating unsatisfactory recording has occurred requiring a rerecording whenever there is a predetermined lack of comparison and satisfactory recording not requiring a rerecording when such comparison matches even though there are error conditions.
Claim 11
Dependent Claim
63 words
The method set forth in claim 7 further dividing said sets along a plurality of parallel tracks on a magnetic recording media; and causing said subsets to lie among the tracks such that at least one signal in each subset is from each track, and causing said quality signal to be associated with each said track and the respective subset across said media.
Claim 12
Dependent Claim
88 words
The method set forth in claim 8 wherein said error detection and correction code bits are capable of correcting a plurality of tracks in error in association with said quality signals; and said predetermined lack of comparison indicating an unsatisfactory recording whenever either (1) said plurality of tracks is in error irrespective of said comparison or (2) one less than said plurality of tracks is in error with any mismatch between any error detection pointed to track in error and said any of said quality signal error pointers.
Claim 13
Independent Claim
95 words
The method of recording digital signals on a record media; including the steps of: recording digital data signals and associated digital check bit signals on said record media; determining the quality of recording of said digital signals and the error status thereof; and comparing the quality and error status and indicating a rerecording is necessary when comparison indicates said quality and status indicate different error locations, and an acceptable recording whenever there are no errors indicated by said status or there is a match of indicated error locations up to a predetermined number of errors.
Claim 14
Independent Claim
95 words
The method of recording digital signals on a record media; including the steps of: recording digital data signals and associated digital check bit signals on said record media; determining the quality of recording of said digital signals and the error status thereof; and comparing the quality and error status and indicating a rerecording is necessary when comparison indicates said quality and status indicate different error locations, and an acceptable recording whenever there are no errors indicated by said status or there is a match of indicated error locations up to a predetermined number of errors.
References Cited (Backward Citations)
US3639900A
Cited
US3675200A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |