OTHOCORE, A LOW-COST NAVIGATIONAL COMPUTER MEMORY

Dr. J. S. Sallo and W. A. England

Peer Reviewed

Abstract:	Honeywell has for the past several years been pursuing the development of a low-cost memory which exhibits desirable performance features for a navigational computer. The results of this effort is the Orthocore. The basic research on this device is conducted at the Corporate Research Center in Hopkins, Minnesota. That portion of this program which is presently applicable to system engineering has been transferred to the Engineering Department of St. Petersburg, Florida, where it is being incorporated into new computer designs. In the design of this device a “wish list” for navigational memory systems was compiled. It was concluded that the memory module of the ideal navigational system should have a very low cost per bit. Aside from the obvious advantages, this will permit increased reliability through redundancy, if desired. The memory should have extreme reliability with no moving parts, no components which could be damaged by vibration, and no standby power requirement. The memory should be stable with respect to temperature fluctuations so that temperature compensation circuitry or thermostating of the memory are not required. The memory should be insensitive to radiation and stray magnetic fields. Large signal outputs should be available with a low noise level. Low power consumption should be coupled with high operating speeds and very small memory size. In the usual design philosophy of navigational computers, a non-destructive readout (NDRO) of the memory is required. In the general case the bulk of the memory is loaded prior to the mission and is a read-only memory during the mission. This portion of the memory is referred to as cold storage. The balance of the memory is a scratch pad read-write memory, referred to as hot storage. In the ideal system the hot storage will also have the NDRO feature. It would be a further advantage if the hot and cold storage were the same memory system. This would result in an economy of electronics and of memory space even though the write electronics for the cold storage are detached prior to the mission. The Orthocore memory concept (1) in its present state of development provides many of the items on this “wish list”. The purpose of this paper is to describe the advantages of this concept for navigational systems.
Published in:	NAVIGATION: Journal of the Institute of Navigation, Volume 11, Number 1
Pages:	69 - 74
Cite this article:	Sallo, Dr. J. S., England, W. A., "OTHOCORE, A LOW-COST NAVIGATIONAL COMPUTER MEMORY", NAVIGATION: Journal of The Institute of Navigation, Vol. 11, No. 1, Spring 1964, pp. 69-74.
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