Patent US3654618A successfully refreshed from Google Patents.
US3654618A
Expired / Lapsed
US
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Magnetic tape unit control system
Assignee: Fujitsu Ltd
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Filing: 1970-10-23
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Granted: 1972-04-04
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Expires: 1990-10-23
Abstract
Abstract Instruction decoding means decodes a received instruction. The instruction decoding means comprises a plurality of circuits each representing a different instruction and each providing an output signal at its output and decoding control means connected to each of the circuits for directing the decoded instruction in accordance with its contents to the input of a selected one of said circuits. Each of a plurality of storage circuits is coupled to the output of a corresponding one of the circuits of the instruction decoding means for storing the output signals of said circuits. A read and write circuit connected to the outputs of some of the storage circuits designates a selected one of a readout and a writein instruction and stores the designation in accordance with the contents of the storage circuits to which the read and write circuit is connected. A packing density circuit connected to the outputs of the others of the storage circuits designates a selected one of a first packing density and a second packing density and stores the designation in accordance with the contents of the storage circuits to which the packing density circuit is connected. The output of the read and write circuit is coupled to an input of the packing density circuit for designating the second packing density in the packing density circuit when the read and write circuit designates a readout. A packing density identification burst detecting means has an input coupled to a readout head of a magnetic tape for detecting the existence on the magnetic tape of a packing density identification burst. The output of the packing density identification burst detecting means is coupled to an input of the packing density circuit for designating the first packing density in said packing density circuit when the packing density identification burst detecting means fails to detect a packing density identification burst in the magnetic tape.
Inventors
- 👤 Kaoru Kanda
- 👤 Tadahiro Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:09
CPC Classifications
G; G06; G06F; G06F3/00; G06F3/06; G06F3/0601; G11; G11B; G11B15/00; G11B15/005; G06F3/0668; G06F3/0671; G06F3/0673; G06F3/0682
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
331 words
A control system for a magnetic tape unit, comprising: input means for providing an instruction; instruction decoding means connected to said input means for decoding the instruction, said instruction decoding means comprising a plurality of circuits, each representing a different instruction and each having an input and one output and providing an output signal at its output, and decoding control means connected to each of said circuits for directing the decoded instruction in accordance with its contents to the input of the corresponding one of said circuits; a read and write circuit, having inputs connected to the outputs of certain of the instruction decoding means, for designating the selection of a readout or a written in instruction, and for storing said designation in accordance with the contents of the instruction decoding means to which said read and write circuit is connected; a packing density circuit, having inputs connected to the outputs of the remaining instruction decoding means, for designating the selection of a first packing density or a second packing density, and for storing said designation in accordance with the contents of the instruction decoding means to which said packing density circuit is connected; coupling means, connecting an output of the read and write circuit to an input of the packing density circuit, for designating the second packing density in said packing density circuit when the read and write circuit designates a readout; a readout head for reading out data stored on the magnetic tape unit; packing density identification burst detecting means, having an output and an input coupled to said readout head, for detecting the existence on the magnetic tape of a packing density identification burst; and additional coupling means, connecting the output of the packing density identification burst detecting means to an input of the packing density circuit, for designating the first packing density in said packing density circuit when said packing density identification burst detecting means fails to detect a packing density identification burst in the magnetic tape.
Claim 2
Dependent Claim
331 words
A control system for a magnetic tape unit, comprising: input means for providing an instruction; instruction decoding means connected to said input means for decoding the instruction, said instruction decoding means comprising a plurality of circuits, each representing a different instruction and each having an input and one output and providing an output signal at its output, and decoding control means connected to each of said circuits for directing the decoded instruction in accordance with its contents to the input of the corresponding one of said circuits; a read and write circuit, having inputs connected to the outputs of certain of the instruction decoding means, for designating the selection of a readout or a written in instruction, and for storing said designation in accordance with the contents of the instruction decoding means to which said read and write circuit is connected; a packing density circuit, having inputs connected to the outputs of the remaining instruction decoding means, for designating the selection of a first packing density or a second packing density, and for storing said designation in accordance with the contents of the instruction decoding means to which said packing density circuit is connected; coupling means, connecting an output of the read and write circuit to an input of the packing density circuit, for designating the second packing density in said packing density circuit when the read and write circuit designates a readout; a readout head for reading out data stored on the magnetic tape unit; packing density identification burst detecting means, having an output and an input coupled to said readout head, for detecting the existence on the magnetic tape of a packing density identification burst; and additional coupling means, connecting the output of the packing density identification burst detecting means to an input of the packing density circuit, for designating the first packing density in said packing density circuit when said packing density identification burst detecting means fails to detect a packing density identification burst in the magnetic tape.
Claim 3
Dependent Claim
28 words
A magnetic tape unit control system as claimed in claim 1, wherein each of the plurality of circuits of the instruction decoding means comprises a flip flop circuit.
Claim 4
Dependent Claim
28 words
A magnetic tape unit control system as claimed in claim 2, wherein both the read and write circuit and the packing density circuit comprise a flip flop circuit.
Claim 5
Dependent Claim
115 words
A magnetic tape unit control system as claimed in claim 3, wherein the read and write flip flop circuit has a reset output and the packing density flip flop circuit has a reset input and a reset output, and the coupling means comprises an AND gate, having an input connected to the reset output of the read and write flip flop circuit and another input coupled to the instruction decoding means, and an OR gate having an input connected to the output of the AND gate, another input connected to the reset output of the packing density flip flop circuit, and an output connected to the reset input of the packing density flip flop circuit.
Claim 6
Dependent Claim
114 words
A magnetic tape unit control system as claimed in claim 3, wherein the packing density flip flop circuit has a set input and one of the plurality of flip flop circuits has a set input and a set output connected to the set input of the packing density flip flop circuit, and the additional coupling means comprises a NOT circuit having an output and an input connected to the oUtput of the identification burst detection circuit, an OR gate having an input connected to the output of the NOT circuit, another input connected to the instruction decoding means, and an output connected to the set input of the one of the flip flop circuits.
Claim 7
Dependent Claim
255 words
A magnetic tape unit control system as claimed in claim 3, wherein the packing density identification burst detecting means comprises amplifying means for amplifying the data read out by the readout head and producing an amplified data output signal, first limit circuit means for limiting the output signal of the amplifying means at a predetermined constant voltage limit level and for producing a square pulse sequence output, first integrating circuit means for integrating each pulse of the pulse sequence output of the first limit circuit means and producing an integrated output signal, second limit circuit means for limiting the integrated output signal of the first integrated circuit means at a predetermined constant voltage limit level and producing an output signal, second integrating circuit means for integrating the output signal of the second limit circuit means at a larger time constant than that of the first integrating circuit means and producing an output signal, third limit circuit means for limiting the output signal of the second integrating circuit means at a predetermined constant voltage limit level and producing an output signal, third integrating circuit means for integrating the output signal of the third limit circuit means at a larger time constant than that of the second integrating circuit means and producing an output signal, fourth limit circuit means for limiting the output signal of the third integrating circuit means at a predetermined constant voltage limit level and producing an output signal, and second output means for providing the output signal of the fourth limit circuit means.
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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) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |