Browse Prior Art Database

Selection of Records for Sorting by Location Address Rearrangement

IP.com Disclosure Number: IPCOM000096077D
Original Publication Date: 1964-Dec-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Dirks, GH: AUTHOR

Abstract

This is a sort control system for variable length fields of the same size, having magnetic disk, delay line implementation.

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Selection of Records for Sorting by Location Address Rearrangement

This is a sort control system for variable length fields of the same size, having magnetic disk, delay line implementation.

Key fields of several records are read from the disk and are compared. Their relative values determine the transfer of their addresses between a pair of delay line stores. The addresses of records having equal key fields maintain their original order. The records can then be accessed sequentially according to the sorted sequence of their addresses.

The records are stored in disk memory 10. Their addresses are synchronously stored either in delay line store 12 or store 14. The key fields are recognized and read by key selector 16. The addresses of their records are transferred between stores 12 and 14 and shifted relative to one another as determined by the sequential bit values in the key fields. The roles of stores 12 and 14 interchange each bit-period. After the last bit has been processed, stores 12 and 14 hold the addresses in the order of the sort.

The interchange between stores 12 and 14 is controlled by 1's counter 18 and 0's counter 20. As identified by bit selector 30, if the bit from the key field is a 0, counter 20 gives the position in store 12 or 14 into which the corresponding address is to be transferred. If the bit is 1, counter 18 does this. Operation is through comparator 34 which controls interchange between stores 12 and 14.

At the beginning of each bit-pe...