US3602892A
Expired / Lapsed
US
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Multitrack high bit density record and reproduce system
Assignee: Leach Corp
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Filing: 1969-04-07
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Granted: 1971-08-31
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Expires: 1989-04-07
Abstract
Abstract A system for recording bit densities of 6,000 to 16,000 bits per linear inch per track and higher, is described wherein parallel track recording is employed. At such high densities, extreme data alignment problems are presented due to static and dynamic skew from one track to another. In the disclosed invention, each track of serial data includes its own synchronizing signal that is recorded coherently with useable data signals. The synchronizing signal has a bit cell duration different from the bit cell duration allotted to useable data. This bit cell duration difference is decoded at the reproduce location and indicates that useable data is immediately following. Each track also has associated therewith at the reproduce location, a multibit buffer which receives data for that track asynchronously with respect to the other tracks. Each track''s input addressing and input bit shifting within each track''s multibit buffer is controlled by a clock signal derived from the recovered data for that track after that track''s own synchronizing signal has been decoded. Each track''s buffer has sufficient capacity to store several multibit data words in one portion of the buffer, while another portion of that buffer is available for output data addressing and output data shifting. Data readout from all of the buffers is provided under control of one arbitrarily selected track at the reproduce station which is designated as a ''''master track.'''' That track''s synchronizing signal, and that track''s derived clock signal, are employed to synchronously output data in parallel from all of the buffers.
Inventors
- 👤 Kermit A Norris
- 👤 William R Goodale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:13
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G11; G11B; G11B20/00; G11B20/10; G11B20/14; G11B20/1403; G11B20/1407; G11B20/1419; G11B20/20; G06F3/0668; G06F3/0671; G06F3/0673; G06F3/0682
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
124 words
A system for formatting signal storage on a magnetic medium having at least one recording track in which binary data is to be stored at a fixed repetitive bit cell duration rate, said system comprising: means recording, prior to data to be stored in said one recording track, a plurality of start of message synchronizing signals having a fixed and repetitive bit cell duration rate which is different from the fixed repetitive rate for the data; means for coherently recording in said track at least one start signal of a selected binary value at said data rate immediately following said synchronizing signal; and means for coherently recording after said start signal random binary data to be written in said track at said data rate.
Claim 2
Independent Claim
124 words
A system for formatting signal storage on a magnetic medium having at least one recording track in which binary data is to be stored at a fixed repetitive bit cell duration rate, said system comprising: means recording, prior to data to be stored in said one recording track, a plurality of start of message synchronizing signals having a fixed and repetitive bit cell duration rate which is different from the fixed repetitive rate for the data; means for coherently recording in said track at least one start signal of a selected binary value at said data rate immediately following said synchronizing signal; and means for coherently recording after said start signal random binary data to be written in said track at said data rate.
Claim 3
Dependent Claim
106 words
A system in accordance with claim 1 wherein said signals recorded on said track are in split-phase mark form, such signals being characterized in that said synchronizing signals comprise: a continuous signal having signal level transitions at the bit cell boundaries and an additional level transition substantially at the middle of a bit cell at said synchronizing signal rate; and said start signal also comprises a continuous signal coherent with the last trailing edge of said synchronizing signal and also having signal level transitions at said bit cell boundaries and an additional level transition substantially at the middle of a bit cell at said data rate.
Claim 4
Dependent Claim
47 words
The system of claim 1 further comprising: means for reproducing the recorded signals; first means for delaying said reproduced signals by one bit cell duration at said data rate; and second means for delaying said reproduced signals by 1 1/2 bit cell durations at said data rate.
Claim 5
Dependent Claim
28 words
The system of claim 3 wherein said synchronizing signals have a repetitive bit cell duration equal to 1 1/2 times the bit cell duration at said data rate.
Claim 6
Dependent Claim
112 words
The system of claim 4 further comprising: decoding means at the reproduce location, said decoding means comprising first and second phase comparison means, said first phase comparison means receiving as inputs the reproduced signals and the same reproduced signals delayed by one data bit cell duration whereby said first phase comparison means has a two discrete level output pattern corresponding respectively to said decoded synchronizing and start signals, said second phase comparison means receiving as inputs the reproduced signAls and the same reproduced signals delayed by 1 1/2 data bit cell durations, said first and second phase comparison means further providing a unique output pattern when decoding said synchronizing and start signals.
Claim 7
Dependent Claim
38 words
The system of claim 5 further comprising: first and second filter means, said first filter means receiving the output of said first phase comparison means, said second filter means receiving the output of said second phase comparison means.
Claim 8
Dependent Claim
45 words
The system of claim 6 further comprising: first detection means receiving the outputs from said first and second filter means for detecting the presence of said unique output pattern, said detection means further adapted to thereafter emit a START command upon receiving said START signal.
Claim 9
Dependent Claim
166 words
The system of claim 7 wherein the start and random data signals are in split-phase mark format such that a one bit delayed version of itself compares with like phases for durations substantially equal to a bit cell interval and/or compares with opposite phases for durations substantially equal to a bit cell interval, and further comprising: means including said first delay means and said first phase comparison means for emitting one data level for like phases and another data level for opposite phases in the compared signal; derived clock means for deriving, from selected transitions of the split phase mark signals, a clock signal synchronized with the decoded data levels; shift register means having an input and an output portion; and input address means response to the output of said clock means, the start signal and the decoded output data signal from said data level emitting means, for placing the decoded data into assigned shift register locations in the input portion of said shift register means.
Claim 10
Dependent Claim
127 words
The system of claim 8 further comprising: output address means for gating out the data bits from the output portion of said shift register means; speed comparison means for comparing the speed at which input data bits fill said input portion of the shift register means with the speed at which data bits are outputted from the output portion of said shift register, said speed comparison means providing a voltage output indicative of the relation of said compared speed; and means connected to said output address means and responsive to said speed comparison means for varying the rate at which data is outputted from said shift register means, whereby said output portion of said shift register means may be substantially maintained at a predetermined partially filled level.
Claim 11
Dependent Claim
93 words
The system of claim 9 further comprising: means for coherently recording a plurality of end of message synchronizing signals immediately subsequent to the last data signal, said synchronizing signals having a fixed and repetitive bit cell duration rate which is different from the fixed repetitive bit cell duration of the data rate; and means for coherently recording a STOP signal immediately subsequent to said plurality of end of message synchronizing signals, said STOP signal comprising at least one binary value of a given signal in said split-phase mark format at said data rate.
Claim 12
Dependent Claim
54 words
The system of claim 10 further comprising: comparator means responsive to said end of message synchronizing signal and said STOP signal for preventing the outputting from the output portion of said shift register means when the first bit of nondata signal is shifted into the last output stage of the output shift register means.
Claim 13
Dependent Claim
145 words
In a memory system having at least one record channel, at least one reproduce channel and a magnetic storage medium, data bit cell duration defining means for emitting a repetitive cycle of data intervals at a fixed predetermined data rate; means for recording in split phase format at least a pair of signals of known binary valves continuous with and one each of said pair bracketing in time a synchronizing signal; synchronizing signal emitting meanS associated with said bit cell duration defining means for coherently emitting after the first signal of said pair a plurality of synchronizing signals having a repetitive bit cell duration different from said data bit cell duration; and means for coherently inhibiting said synchronizing signal emitting means when a selected synchronizing signal bit cell boundary coincides with a selected data interval bit cell boundary of the second signal of said pair.
Claim 14
Dependent Claim
145 words
In a memory system having at least one record channel, at least one reproduce channel and a magnetic storage medium, data bit cell duration defining means for emitting a repetitive cycle of data intervals at a fixed predetermined data rate; means for recording in split phase format at least a pair of signals of known binary valves continuous with and one each of said pair bracketing in time a synchronizing signal; synchronizing signal emitting meanS associated with said bit cell duration defining means for coherently emitting after the first signal of said pair a plurality of synchronizing signals having a repetitive bit cell duration different from said data bit cell duration; and means for coherently inhibiting said synchronizing signal emitting means when a selected synchronizing signal bit cell boundary coincides with a selected data interval bit cell boundary of the second signal of said pair.
Claim 15
Dependent Claim
41 words
The system of claim 12 wherein the synchronizing signal is also in a split phase mark format of a known binary value and wherein said synchronizing signal bit cell duration is equal to 1 1/2 times the data bit cell duration.
Claim 16
Dependent Claim
41 words
The system of claim 13 further comprising: decoding means at the reproduce location receiving the data and synchronizing signals for converting the data signals to two-level binary signals, said decoding means producing a unique output pattern upon receiving said synchronizing signals.
Claim 17
Independent Claim
130 words
A method of recording and recovering high bit density in a magnetic memory system including a magnetic medium, and a record and reproduce channel comprising the steps of: recording serial binary data on said medium in a split phase mark format with a fixed data bit cell duration; recording coherently a synchronizing signal prior to recording the serial binary data, with a bit cell duration different from the data bit cell duration; recording coherently a start signal after recording the synchronizing signal but before recording the binary data, with a bit cell duration equal to the data bit cell duration; recovering the recorded signals from the magnetic medium; delaying the recovered signals by one data bit cell duration; and delaying the recorded signal by 1 1/2 data bit cell durations.
Claim 18
Independent Claim
130 words
A method of recording and recovering high bit density in a magnetic memory system including a magnetic medium, and a record and reproduce channel comprising the steps of: recording serial binary data on said medium in a split phase mark format with a fixed data bit cell duration; recording coherently a synchronizing signal prior to recording the serial binary data, with a bit cell duration different from the data bit cell duration; recording coherently a start signal after recording the synchronizing signal but before recording the binary data, with a bit cell duration equal to the data bit cell duration; recovering the recorded signals from the magnetic medium; delaying the recovered signals by one data bit cell duration; and delaying the recorded signal by 1 1/2 data bit cell durations.
Claim 19
Dependent Claim
43 words
The method of claim 15 further comprising the additional steps of: comparing the recovered signals with the recovered signals delayed by one data bit cell duration; and comparing the recovered signals with the recovered signals delayed by 1 1/2 data bit cell durations.
Claim 20
Independent Claim
142 words
A system for formatting signal storage on a magnetic medium having at least one recording track in which binary data is to be stored in split phase mark form having a fixed repetitive bit cell duration rate, said system comprising: means recording, prior to data to be stored in said one recording track, a plurality of start of message synchronizing signals of known binary values in split-phase mark form having a fixed and repetitive bit cell duration rate which is different from the fixed repetitive rate for the data; means for coherently recording in said track at least one start signal of a selected binary value in split-phase mark form at said data rate immediately following said synchronizing signal; and means for coherently recording after said start signal random binary data to be written in said split-phase form at said data rate.
Claim 21
Independent Claim
142 words
A system for formatting signal storage on a magnetic medium having at least one recording track in which binary data is to be stored in split phase mark form having a fixed repetitive bit cell duration rate, said system comprising: means recording, prior to data to be stored in said one recording track, a plurality of start of message synchronizing signals of known binary values in split-phase mark form having a fixed and repetitive bit cell duration rate which is different from the fixed repetitive rate for the data; means for coherently recording in said track at least one start signal of a selected binary value in split-phase mark form at said data rate immediately following said synchronizing signal; and means for coherently recording after said start signal random binary data to be written in said split-phase form at said data rate.
Claim 22
Dependent Claim
30 words
A system in accordance with claim 17 wherein: said fixed repetitive bit cell rate of said synchronizing signals is a definite ratio as compared with said data bit cell rate.
Claim 23
Dependent Claim
21 words
A system in accordance with claim 18 wherein said definite ratio for said synchronizing rate is two-thirds of the data rate.
Claim 24
Dependent Claim
57 words
A system in accordance with claim 19 and further comprising: means for reproducing signals recorded on said track of said magnetic medium; and means responsive to said ratio and the coherency between said synchronizing signals and said start signal for emitting a data recovery command concurrently with recovery of said random binary data by said reproducing means.
Claim 25
Dependent Claim
91 words
A system in accordance with claim 20 wherein said data recovery command emitting means comprises: first means for decoding said synchronizing signals as one fixed signal level for a given time duration and said start signal as a second different signal level following said given time duration; second means fOr decoding said synchronizing signals as said second different signal level greater than the given time duration and the time required for the start signal; and means responsive to coincidence of both of said second levels for emitting said data recovery command.
Claim 26
Dependent Claim
62 words
A system in accordance with claim 21 wherein said first decoding means comprises: a delay equal to the duration of a bit cell as said data rate; and further comprising first comparator means connected to receive said reproduced signal and said signal from said first delay means for emitting said first and second signal levels for said synchronizing and start signal respectively.
Claim 27
Dependent Claim
71 words
A system in accordance with claim 22 wherein said second decoding means comprises: a delay equal to the duration of a bit cell at said synchronizing rate; and further comprising second comparator means connected to receive said reproduced signal and said signal from said second delay means and responsive to the received signals for emitting said second signal level throughout the time duration of the synchronizing signal and said start signal.
Claim 28
Dependent Claim
34 words
A system in accordance with claim 23 wherein said second delay means has a time delay that is equal to 1 1/2 times the time duration of a bit cell at said data rate.
Claim 29
Dependent Claim
18 words
A system in accordance with claim 23 where said first and second comparison means comprises exclusive NOR circuits.
Claim 30
Dependent Claim
105 words
A system for recovering signals formatted in accordance with claim 17 comprising: first decoding means for decoding said start of message synchronizing signals as one fixed level; second decoding means for decoding said start of message synchronizing signals as a second fixed level; a synchronizing detector connected to receive said first and second fixed levels and responsive to said start signal for emitting a start command; and means associated with said synchronizing detector and responsive to said start command for emitting a data read signal concurrently with the appearance of the first signal of random data to be recovered from the track of said medium.
Claim 31
Dependent Claim
45 words
A system in accordance with claim 17 and further comprising: means for coherently recording in said one track prior to said start of message synchronizing signals at least one noise squelching signal of a selected binary value in split-phase mark form at said data rate.
Claim 32
Dependent Claim
44 words
A system in accordance with claim 17 and further comprising: means for coherently recording between said random data pattern and said end of message synchronizing signals at least one noise-squelching signal of a selected binary value in split-phase mark form at said data rate.
Claim 33
Dependent Claim
90 words
A system for formatting signal storage for a magnetic medium accordance with claim 17 and further comprising: means for coherently recording, in said track following said random data, a plurality of end of message synchronizing signals having a fixed and repetitive bit cell duration rate which is the same as that of the start of message synchronizing signals; and means for coherently recording in said track after said end of message synchronizing signals a stop signal of a selected binary value in split phase mark form at said data rate.
Claim 34
Dependent Claim
190 words
In a magnetic memory system having at least one record channel, at least one reproduce channel and a magnetic storage medium, said system being adapted to record on said magnetic storage medium random serial binary data represented in a split phase mark format having a fixed and repetitive data bit cell rate: means recording a plurality of synchronizing signals prior to recording the data, said synchronizing signals having a fixed repetitive bit cell rate which is different from the data bit cell rate; means synchronizing a last boundary transition of the synchronizing signal substantially coincidental and continuous with a first boundary transition of a signal to be recorded immediately after said synchronizing signal; means responsive to said Synchronizing means for recording at least one START signal in split phase mark form immediately at said boundary transitions immediately before the random serial data signals to be recorded; and means responsive to the differences in the bit cell rates and the coherency of the synchronizing signals and said START signal for emitting a data recovery command coincidental with the appearance of said random serial binary data to be recovered from said medium.
Claim 35
Dependent Claim
190 words
In a magnetic memory system having at least one record channel, at least one reproduce channel and a magnetic storage medium, said system being adapted to record on said magnetic storage medium random serial binary data represented in a split phase mark format having a fixed and repetitive data bit cell rate: means recording a plurality of synchronizing signals prior to recording the data, said synchronizing signals having a fixed repetitive bit cell rate which is different from the data bit cell rate; means synchronizing a last boundary transition of the synchronizing signal substantially coincidental and continuous with a first boundary transition of a signal to be recorded immediately after said synchronizing signal; means responsive to said Synchronizing means for recording at least one START signal in split phase mark form immediately at said boundary transitions immediately before the random serial data signals to be recorded; and means responsive to the differences in the bit cell rates and the coherency of the synchronizing signals and said START signal for emitting a data recovery command coincidental with the appearance of said random serial binary data to be recovered from said medium.
Claim 36
Dependent Claim
304 words
In a high density system having a plurality of parallel tracks of data recorded on a magnetic storage medium with spacial displacement of each tracks first and subsequent data signals relative to all other tracks first and subsequent data signals, said spacial displacement being at least more than the spacial allotment of one data bit period and in some instances being more than the spacial allotment of many data bit periods as a result of dynamic and static skew and other disturbances inherent in the system, the improvement comprising: means for recording synchronizing signals on each track on the magnetic medium in a split-phase format which assures signal transitions at a midbit location and at each bit cell boundary at a first fixed repetition rate; means for coherently recording between data to be recorded and the synchronizing signal on each track at least one binary signal of a given bit designation in said split phase form at a second rate different from said first repetition rate; means at the reproduce location for reproducing the recorded signals from each individual track; means for delaying the reproduced signal by one bit cell duration at both the first and second repetition rates; first means individual for each track and associated with said first rate for decoding a delayed and nondelayed reproduced signal as one continuous level for the duration of the synchronizing signal; second means individual for each track and associated with said second rate for decoding a delayed and nondelayed reproduce signal as a second continuous level for the duration of the synchronizing level; and means responsive to said first and second means and a change in said level outputs thereof upon occurrence of said binary signal for emitting a start command just prior to the occurrence of data signals to be recovered from said medium.
Claim 37
Dependent Claim
304 words
In a high density system having a plurality of parallel tracks of data recorded on a magnetic storage medium with spacial displacement of each tracks first and subsequent data signals relative to all other tracks first and subsequent data signals, said spacial displacement being at least more than the spacial allotment of one data bit period and in some instances being more than the spacial allotment of many data bit periods as a result of dynamic and static skew and other disturbances inherent in the system, the improvement comprising: means for recording synchronizing signals on each track on the magnetic medium in a split-phase format which assures signal transitions at a midbit location and at each bit cell boundary at a first fixed repetition rate; means for coherently recording between data to be recorded and the synchronizing signal on each track at least one binary signal of a given bit designation in said split phase form at a second rate different from said first repetition rate; means at the reproduce location for reproducing the recorded signals from each individual track; means for delaying the reproduced signal by one bit cell duration at both the first and second repetition rates; first means individual for each track and associated with said first rate for decoding a delayed and nondelayed reproduced signal as one continuous level for the duration of the synchronizing signal; second means individual for each track and associated with said second rate for decoding a delayed and nondelayed reproduce signal as a second continuous level for the duration of the synchronizing level; and means responsive to said first and second means and a change in said level outputs thereof upon occurrence of said binary signal for emitting a start command just prior to the occurrence of data signals to be recovered from said medium.
Claim 38
Dependent Claim
138 words
The system in accordance with claim 31 wherein the first means comprises a first signal comparison means and the second means comprises a second signal comparison means; said system further comprising: means for applying a reproduced signal and the same reproduced signal delayed by one data bit cell duration at said first rate to said first signal comparison means for emitting a first one of the two discrete level output signals; means for applying to said second signal comparison means a reproduced signal and the same reproduced signal delayed by one bit cell durations at said second repetition rate for emitting a second one of said two discrete level output signals; and said start signal emitting means comprises a logic gating means responsive to said difference in output levels and a change therein for emitting said start command.
Claim 39
Dependent Claim
136 words
The system in accordance with claim 31 and further comprising: means for designating one of the recorded tracks as a master track; derived clock means for deriving from selected transitions of the split-phase mark signals of said master track a clock signal synchronized with the decoded data levels for said master track; shift register means individual to each track with each shift register means having an input and an output portion; means individual to each track and responsive to a start command for each track for serially shifting decoded data from that track into its associated input portion of that tracks shift register asynchronously relative to said other tracks; and means responsive to the master tracks derived clock signal for synchronously shiftinG data in parallel from all output portions of all shift registers for all tracks.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-30 | 1975-03-01 | 1975-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-30 | 1979-03-01 | 1979-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-30 | 1983-03-01 | 1983-08-31 | $7700.00 | Window Closed / Lapsed |