US3824563A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data storage track padding apparatus
Assignee: International Business Machines Corp
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Filing: 1973-04-13
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Granted: 1974-07-16
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Expires: 1993-04-13
Abstract
Abstract In data processing systems, several data storage files, such as disk files, are operated by a single, shared control unit for conducting normal read/write functions. Apparatus is located at and provided for each of the data storage files to assume control of the writing function from the control unit to pad a track with null characters from the end of the last record to a predetermined point on the track sensed by the file. The apparatus includes a local oscillator and apparatus for supplying the padding bits signals from the oscillator beginning with the termination of the control unit write gate signal for the track and continuing until a predetermined point of the track is detected. Apparatus is also provided for signaling the control unit that padding by the device is in progress and for signalling the control unit prior to the predetermined point.
Inventors
- 👤 F Lutz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:51
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/10; G06F13/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
184 words
An apparatus within a disk file for assuming control of the disk file from a control unit at the end of the last format write operation being performed under control of the control unit so as to release the control unit for operation with other disk files attached to that control unit, said apparatus performing a padding to index operation independent of the control unit, the apparatus comprising: a local oscillator for producing null characters; first means for determining the end of the last format write operation; second means connected to said firsT means for maintaining the status within the disk file to be the same status as existed during the last performed format write operation; gate means connected to the local oscillator and the first means for gating the output of the local oscillator to the write circuitry within the disk file until he occurrence of the next index signal is sensed by the disk file for recording the null character signals so as to perform the padding to index operation independent of control of the control unit associated with that disk file.
Claim 2
Independent Claim
184 words
An apparatus within a disk file for assuming control of the disk file from a control unit at the end of the last format write operation being performed under control of the control unit so as to release the control unit for operation with other disk files attached to that control unit, said apparatus performing a padding to index operation independent of the control unit, the apparatus comprising: a local oscillator for producing null characters; first means for determining the end of the last format write operation; second means connected to said firsT means for maintaining the status within the disk file to be the same status as existed during the last performed format write operation; gate means connected to the local oscillator and the first means for gating the output of the local oscillator to the write circuitry within the disk file until he occurrence of the next index signal is sensed by the disk file for recording the null character signals so as to perform the padding to index operation independent of control of the control unit associated with that disk file.
Claim 3
Dependent Claim
43 words
The apparatus as set forth in claim 1 further comprising: a sector decoder for generating a signal indicative of the relative position of the next index pulse to the sector now being operated upon by the read/write circuitry associated with the disk file.
Claim 4
Dependent Claim
58 words
The apparatus as set forth in claim 2 further comprising: third means connected to said sector detector and said first means for generating a signal to the control unit for indicating that a padding to index operation will occur upon the conclusion of the last format write operation to be performed under the control of the control unit.
Claim 5
Dependent Claim
58 words
The apparatus as set forth in claim 2 further comprising: a fourth means connected to said sector detector in said first means for generating a signal to the control unit that the disk file is within range of completing its padding to index operation so as to be ready to accept a polling operation from the control unit.
Claim 6
Dependent Claim
53 words
The apparatus as set forth in claim 3 further comprising: a fourth means connected to said sector detector in said first means for generating a signal to the control unit that the disk file is completing its padding to index operation and is ready to accept a polling operation from the control unit.
Claim 7
Dependent Claim
48 words
The apparatus as set forth in claim 1 further comprising: fifth means connected to said first means for inhibiting command to the disk file from the file control unit which would generate an error condition while a padding to zero operation is being performed by said disk file.
Claim 8
Dependent Claim
48 words
The apparatus as set forth in claim 3 further comprising: fifth means connected to said first means for inhibiting command to the disk file from the file control unit which would generate an error condition while a padding to zero operation is being performed by said disk file.
Claim 9
Dependent Claim
48 words
The apparatus as set forth in claim 4 further comprising: fifth means connected to said first means for inhibiting command to the disk file from the file control unit which would generate an error condition while a padding to zero operation is being performed by said disk file.
Claim 10
Dependent Claim
48 words
The apparatus as set forth in claim 5 further comprising: fifth means connected to said first means for inhibiting command to the disk file from the file control unit which would generate an error condition while a padding to zero operation is being performed by said disk file.
Claim 11
Independent Claim
150 words
A method of assuming control of a writing means in a data storage file to pad a cyclic data storage medium with null characters from the termination of variable length record data supplied from a source to an index point of said cyclic data storage medium, said source supplying predetermined command signals to command said data storage file for storing said variable length record data, said method comprising the steps of: generating a continuing first sigal in response to a predetermined one of said command signals; sensing said termination of said supplied data; generating null character signals jointly in response to said first signal and said sensing step; generating hold signals to maintain command of said data storage file for storing said null character signals; sensing said index point of cyclic data storage medium to generate an index signal; halting said null character generation in response to said index signal.
Claim 12
Independent Claim
150 words
A method of assuming control of a writing means in a data storage file to pad a cyclic data storage medium with null characters from the termination of variable length record data supplied from a source to an index point of said cyclic data storage medium, said source supplying predetermined command signals to command said data storage file for storing said variable length record data, said method comprising the steps of: generating a continuing first sigal in response to a predetermined one of said command signals; sensing said termination of said supplied data; generating null character signals jointly in response to said first signal and said sensing step; generating hold signals to maintain command of said data storage file for storing said null character signals; sensing said index point of cyclic data storage medium to generate an index signal; halting said null character generation in response to said index signal.
Claim 13
Dependent Claim
78 words
The method of claim 10 wherein said supplied predetermined command signals include a write gate command sIgnal supplied from said source for the duration of said variable length record data, and an address mark command signal supplied from said source at the beginning of each variable length record, and wherein: said first signal generating step occurs in response to said address mark command signal; and said sensing step comprises sensing the termination of said write gate command signal.
Claim 14
Dependent Claim
61 words
The method of claim 11 including the additional steps of: sensing predetermined sectors of said cycle of said cyclic data storage medium; and supplying a pad on signal for said source in response to a predetermined command signal from said source and to a predetermined command signal from said source and to a predetermined status of said predetermined sector sensing step.
Claim 15
Dependent Claim
36 words
The method of claim 12 including the additional step of: supplying an interrupt signal for said source in response to said hold signal generating step and to a predetermined status of said predetermined sector sensing step.
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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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |