US3609703A
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US
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Comparison matrix
Assignee: International Business Machines Corp
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Filing: 1969-06-30
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Granted: 1971-09-28
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Expires: 1989-06-30
Abstract
Abstract A new comparison circuit is adapted to be connected in a row and column array for comparing words applied to the columns of the array with a sequence of words applied to the rows. Each comparison circuit has means for registering a match or a mismatch while corresponding bit positions of the words that are being compared are applied to the column input and the row input of the circuit. A comparison circuit includes means responsive to a match to transmit data from a row input to a column output. The specification describes the circuit as it is arranged to compare key words to a file index with key words supplied by a user of the file and to transmit a data word called a pointer to the user to identify the file location when a match is found.
Inventors
- 👤 Antony Peacock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:51
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/02; G06F16/00; G06F16/90; G06F16/901; G06F16/9017
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
159 words
Search apparatus comprising: an index memory for providing a sequence of search keys at a plurality of outputs followed by pointers each identifying an associated search key; a transactions register for receiving search keys representing a plurality of search requests; timing means for applying the search keys in synchronism with the index keys; a matrix of comparison circuits connected to receive the search keys along column lines and index keys and pointers along row lines, each comparison circuit comprising: an Exclusive OR circuit connected at the intersection of a column key line and a row key line to produce a mismatch signifying signal; latch means connected to be reset to begin a search and to be set in response to a mismatch signal from said Exclusive OR circuit; and a logic gate connected to be responsive to the associated latch means to transmit a pointer from the corresponding row line to the transactions register stage of the corresponding column.
Claim 2
Dependent Claim
159 words
Search apparatus comprising: an index memory for providing a sequence of search keys at a plurality of outputs followed by pointers each identifying an associated search key; a transactions register for receiving search keys representing a plurality of search requests; timing means for applying the search keys in synchronism with the index keys; a matrix of comparison circuits connected to receive the search keys along column lines and index keys and pointers along row lines, each comparison circuit comprising: an Exclusive OR circuit connected at the intersection of a column key line and a row key line to produce a mismatch signifying signal; latch means connected to be reset to begin a search and to be set in response to a mismatch signal from said Exclusive OR circuit; and a logic gate connected to be responsive to the associated latch means to transmit a pointer from the corresponding row line to the transactions register stage of the corresponding column.
Claim 3
Dependent Claim
19 words
The search apparatus of claim 1 in which said matrix includes separate row lines for key and pointer signals.
Claim 4
Dependent Claim
96 words
The search apparatus of claim 2 in which said lAtch means comprises a first latch connected to be set according to a mismatch signal, a second latch connected to control said logic gate to transmit a pointer, and a second logic gate connected to transfer the contents of said first latch to said second latch at the end of matching key comparison, and said apparatus further includes timing means for operating said Exclusive OR circuit and first latch to compare subsequent keys during transfer of a pointer through said logic gate controlled by said second latch.
Claim 5
Dependent Claim
49 words
The search apparatus of claim 3 including a match line for each row and each column and including third logic gate means connecting each comparison circuit to produce a signal on its row and column match lines in response to a match condition at the end of a search.
Claim 6
Dependent Claim
39 words
The search apparatus of claim 1 in which said timing means includes an adjustable counter arranged to produce a selected number of pulses gating bits of keys from said transactions register between pulses controlling the operations between key comparisons.
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) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |