US3618043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information-handling system especially for magnetic recording and reproducing of digital data
Assignee: General Dynamics Corp
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Filing: 1969-11-14
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Granted: 1971-11-02
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Expires: 1989-11-14
Abstract
Abstract A system for storage on a magnetic record medium (tape or disc) of data with an extremely high packing density is described. Binary input information is encoded into a ternary signal for recording. That ternary signal has spectral properties which facilitate recording with extremely high bit-packing density. The ternary signal also contains timing information. On playback the signal is decoded into binary coded ternary form. Timing information with respect to words of ternary data, as well as the individual terts which make up the words, is also derived. The system includes means for synchronizing the reproduced data in accordance with the timing information derived from the data itself, as well as with an external clock, and decodes the data into the original binary form.
Inventors
- 👤 John S Whiting
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:24
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L13/00; H04L13/02; H04L13/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
140 words
A system for providing output data synchronous with successive words of ternary data, each word being constituted of a certain plurality of terts the average level of which is zero, said system comprising a. means responsive to said terts for providing a first timing signal having a repetition rate equal to the repetition rate of said terts and coherent therewith, b. means responsive to said successive ternary words for providing second timing signals when said certain plurality of terts which constitute said words have said zero average levels, and c. first means for detecting valid ternary words when said second timing signals occur simultaneously with the last of a number of said first timing signals equal to said certain plurality, the detection of said valid words indicating that said output data corresponding to said ternary words is in synchronism therewith.
Claim 2
Independent Claim
140 words
A system for providing output data synchronous with successive words of ternary data, each word being constituted of a certain plurality of terts the average level of which is zero, said system comprising a. means responsive to said terts for providing a first timing signal having a repetition rate equal to the repetition rate of said terts and coherent therewith, b. means responsive to said successive ternary words for providing second timing signals when said certain plurality of terts which constitute said words have said zero average levels, and c. first means for detecting valid ternary words when said second timing signals occur simultaneously with the last of a number of said first timing signals equal to said certain plurality, the detection of said valid words indicating that said output data corresponding to said ternary words is in synchronism therewith.
Claim 3
Dependent Claim
61 words
The invention as set forth in claim 1 further comprising second means for detecting the presence of an invalid ternary word when the occurrence of said second timing signal does not coincide with said last of said first timing signals, the detection of said invalid words indicating that said output data corresponding to said ternary words is out of synchronism therewith.
Claim 4
Dependent Claim
130 words
The invention as set forth in claim 2 wherein said first and second detecting means includes a. a counter for counting said first timing signals and providing a first output when said number of first timing signals equal To said certain plurality is counted, b. gates responsive to the simultaneous occurrence of said first output and said second timing signals for providing third outputs representing the detection of said valid words and said gates also being responsive to the occurrence of said second timing signals in the absence of said first output for providing fourth outputs representing the detection of said invalid words, and c. means for applying said invalid word outputs to said counter for reducing the count stored therein upon occurrence of each of said invalid word outputs.
Claim 5
Dependent Claim
112 words
The invention as set forth in claim 2 wherein said directing means includes a. gates responsive to the simultaneous occurrence of said first and second timing signals and said gates also being responsive to the occurrence of said second timing signals in the absence of said first timing signals for producing outputs representing the detection of said valid words or invalid words, respectively, and means for providing an output indicating synchronism between said ternary data and said output data so long as a first plurality of successive ones of said invalid word outputs does not occur after a plurality of successive ones of said invalid word outputs greater than said first plurality.
Claim 6
Dependent Claim
69 words
The invention as set forth in claim 4 wherein frame words are interspersed between successive groups of said ternary words, and including means responsive to said ternary data for providing frame word outputs upon occurrence of said frame words, and wherein means are provided responsive to said frame word outputs for inhibiting the provision of said synchronism indicating output until after occurrence of one of said frame word outputs.
Claim 7
Dependent Claim
183 words
The invention as set forth in claim 4 wherein said means for providing said synchronism indicating output includes a. a first counter for counting said valid word outputs and providing a first output pulse when said greater plurality of valid word outputs is counted, b. a second counter for counting said invalid word outputs for providing a second output pulse when said first plurality of invalid word outputs is counted, c. a flip-flop adapted to be conditioned into its first state by said first pulse and into its second state by said second pulse, said flip-flop providing said synchronism indicating output when in its first state, d. means for inhibiting the application of said valid word outputs to said first counter when said flip-flop is in its first state, e. means for inhibiting the application of said invalid word outputs to said second counter when said flip-flop is in its second state, f. means responsive to each of said invalid word outputs for clearing said first counter, and g. means responsive to each of said valid word outputs for clearing said second counter.
Claim 8
Independent Claim
220 words
A system for detecting errors in a serial stream of ternary data derived from a transmission medium, such as a magnetic record, said data being constituted of successive ternary words each made up of a certain plurality of successive terts having positive, negative and zero levels, the average value of the levels of the terts in each word being zero, said system comprising a. means for examining successive tert groups of said data, each containing said certain plurality of said successive terts, each succeeding group including the terts from the preceding group less the first tert in said preceding group, for providing first outputs when the average value of the levels of the terts making up each of said groups is zero, b. means responsive to the fundamental frequency component of said ternary data for providing second outputs at the repetition rate of the terts of said data and coherent therewith, c. means responsive to said second outputs for producing a timing signal upon occurrence of successive numbers of said second outputs equal to said certain plurality, and d. means responsive to the absence of simultaneous occurrence of sAid timing signals and said first outputs for indicating that the words of said ternary data, occurring when said first outputs do not occur simultaneously with said timing signals, are in error.
Claim 9
Independent Claim
220 words
A system for detecting errors in a serial stream of ternary data derived from a transmission medium, such as a magnetic record, said data being constituted of successive ternary words each made up of a certain plurality of successive terts having positive, negative and zero levels, the average value of the levels of the terts in each word being zero, said system comprising a. means for examining successive tert groups of said data, each containing said certain plurality of said successive terts, each succeeding group including the terts from the preceding group less the first tert in said preceding group, for providing first outputs when the average value of the levels of the terts making up each of said groups is zero, b. means responsive to the fundamental frequency component of said ternary data for providing second outputs at the repetition rate of the terts of said data and coherent therewith, c. means responsive to said second outputs for producing a timing signal upon occurrence of successive numbers of said second outputs equal to said certain plurality, and d. means responsive to the absence of simultaneous occurrence of sAid timing signals and said first outputs for indicating that the words of said ternary data, occurring when said first outputs do not occur simultaneously with said timing signals, are in error.
Claim 10
Dependent Claim
84 words
The invention as set forth in claim 7, wherein said examining means comprises a. means providing storage for at least said certain plurality of terts of said data, b. means for applying said ternary data to said storage means so that each of said successive groups of terts are simultaneously stored therein, and e. means coupled to said storage means and responsive to the sum of the levels of each of the terts in each of said successive groups for providing said first outputs.
Claim 11
Dependent Claim
119 words
The invention as set forth in claim 8 wherein a. said storage means includes a multistage shift register, b. said applying means includes means for applying data corresponding to said terts to the input of the first stage of said register and being responsive to said second outputs for shifting said tert data into and advancing said data between successive stages of said register upon occurrence of each of said second outputs, and c. said sum-responsive means includes means for converting the data stored in said register stages from digital to analog signals summing said analog signals and providing said first outputs when the sum of said analog signals is different from zero by less than a given threshold.
Claim 12
Dependent Claim
71 words
The invention as set forth in claim 9 wherein said means for indicating errors in said ternary words comprises gating means responsive to said timing signals and said first outputs for producing first pulses indicating good ternary words when said first outputs and said timing signals are coincident with each other and second pulses indicating erroneous bad word when said first outputs do not occur in coincidence with said timing signals.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |