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Control Device For Record Searching

IP.com Disclosure Number: IPCOM000098360D
Original Publication Date: 1960-Aug-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 3 page(s) / 70K

Publishing Venue

IBM

Related People

Smith, PF: AUTHOR [+2]

Abstract

(Image Omitted) The circuitry is for scanning a large file for records which compare equally with one or more criteria.

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This is the abbreviated version, containing approximately 53% of the total text.

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Control Device For Record Searching

(Image Omitted)

The circuitry is for scanning a large file for records which compare equally with one or more criteria.

Information is extracted from the file character by character with all bits of each character appearing as simultaneous outputs of read amplifiers 1. The outputs of 1 are compared with the criteria stored in search register 2. AND circuits 3 are provided for the comparison of each bit. The true outputs from amplifiers 1 are compared with the corresponding not true outputs from register 2 and conversely. A lack of identity between the information from register 2 and that from amplifiers 1 produces an output on line 4 connected to the right input of trigger T5. This causes the right output to drop to prevent passage of a signal by AND gate 6. T5 is reset at the end of each record by a signal applied to the left input.

The output of AND 6 is connected to OR circuit 7. The additional inputs to OR 7 are used to simultaneously compare each record for equality with one of a plurality of criteria, in which case duplicate search registers 2, AND gates 3, triggers T5 and AND gates 6 are required for each additional set of criteria.

Each time a character is read from the file by amplifiers 1, clock pulse generator 8 delivers a pulse to counter 9. The capacity of 9 is such that a carry is produced when all character positions on a record have been scanned. The carry signal passes through AND 6, if the search criteria have been met, to provide an equal compare signal at the OR 7 output.

The carry signal is also connected to the address ring and core drivers 10 for core array 11 and serves to select a core corresponding to each record address. When a record compares equally with any one of the search criteria, the corresponding core is switched to the 1 condition. The array 11 contains A and B core planes. A search of the file for records meeting a first criteria may be stored in plane A and a second search according to additional criteria may be recorded in plane B.

A search is initiated by a pulse applied to line 12 which switches triggers T2 and T1 on causing the right outputs to drop. Trigger T3 remains off with its left output down. Both inputs to OR 16 are low and gated sense amplifiers SA 17 and SA 18 are closed.

With T2 and T1 on, equal compare signals pass from OR 7 through AND 19, OR 20, AND 21, OR 22 and inverter INV 23 to the inhibit driver INH A to the array. During the write cycle there is no current in the inhibit winding and the address core is switched to the 1 state.

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At the conclusion of a search according to first criteria, an end of scan pulse is applied to line 25 which turns on trigger T3 to...