Browse Prior Art Database

Reverse Search Through a Cyclic Memory

IP.com Disclosure Number: IPCOM000078810D
Original Publication Date: 1973-Mar-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Bluethman, RG: AUTHOR [+2]

Abstract

A reverse search and relocation of a position flag in a cyclic memory is performed in two memory revolutions. In the first memory revolution, the location of the position flag is detected. In the second memory revolution, the position flag is relocated adjacent to the preceding code of a particular type.

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Reverse Search Through a Cyclic Memory

A reverse search and relocation of a position flag in a cyclic memory is performed in two memory revolutions. In the first memory revolution, the location of the position flag is detected. In the second memory revolution, the position flag is relocated adjacent to the preceding code of a particular type.

When a dynamic shift register memory (DSRM) is connected between a keyboard and a printer for temporarily storing data before printing, it is often advantageous to relocate the position flag in the DSRM to the beginning of a word, line, paragraph or page. In Fig. 1, record flag R represents a reference location or beginning point in the DSRM. Data to be entered into the DSRM is entered one character at a time, immediately to the right of position flag F. F is shifted to the right around each character as characters are printed out of the DSRM. In Fig. 1, F is located between the third and fourth data characters, following the fourth carrier return code CR beyond R.

If it is desired to relocate F to the beginning of a line so that the line may be revised or reprinted, it is necessary to relocate F to a position immediately following a CR. This relocation is performed by scanning the contents of the DSRM through one revolution and determining the present location of F. The present location of F is determined by resetting a counter when R is decoded, and incrementing the counter each time a CR is decoded until F is decoded. On ...