Browse Prior Art Database

Program Storage in a Circulating Memory

IP.com Disclosure Number: IPCOM000098753D
Original Publication Date: 1959-Dec-01
Included in the Prior Art Database: 2005-Mar-08
Document File: 3 page(s) / 82K

Publishing Venue

IBM

Related People

Berkin, GM: AUTHOR

Abstract

In computing machines, it may be desirable to store both program information and data information in a circulating memory.

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Program Storage in a Circulating Memory

In computing machines, it may be desirable to store both program information and data information in a circulating memory.

The upper drawing illustrates circuitry used to read stored program information from an accounting machine magnetic drum. The accounting machine can perform many different types of program functions, only ten of which are shown. The drum has one sync track and a number of different program tracks in addition to the well known information tracks which are not shown. The sync track and the two program tracks, for the purpose of illustration, are shown as broken circles, each track being divided into five data sectors (sectors A through E) and one sync sector. The outside track is the sync track and has sixty-four 1 bits recorded in each data sector and one 1 bit in the sync sector. Each sector of the program tracks, which are the two inside tracks TR1 and TR2, represents one program function which the machine can perform. The presence of a 1 bit at any of the sixty-four numbered bit locations of a sector indicates that the function which the sector represents is to be performed during that numbered program step. For example, a 1 bit in the fifth position of the add sector indicates that the add function is to be performed on the fifth program step.

Ten storage triggers 1 through 10 are turned ON selectively to cause the function shown inside the trigger block to be performed. Trigger 1 is shown to be an information read function and to be on track 2 at sector A. A five position timing ring 11 is used in conjunction with a sixty-four counter 12 to insure that the proper sequence of instructions is performed. Each 1 bit on the sync track sensed by the sync magnetic head 13 causes a pulse to be produced which is fed through an AND circuit 14 to step the sixty-four counter 12.

To illustrate the operation, it is assumed that the first program step is a program read function and the second program step is an information read function. At the start of operation, the sixty-four counter 12 is set so that it produces an output pulse to AND circuits 15 and 16 at the time the first bit position of sector A is under the magnetic heads 17 and 18. At this time stage one of the timing ring 11 is ON, but since there is no 1 bit in the information read sector or in the readin register A sector, the track 1 and trac...