Core rope memory is a form of read-only memory (ROM) for computers, first used by early NASA Mars probes and then in the Apollo Guidance Computer (AGC) designed by MIT and built by Raytheon. Jump to: navigation, search Read-only memory (ROM) is used as a storage medium in computers. ... Jump to: navigation, search A computer is a device or machine for processing information from data according to a program — a compiled list of instruction. ... Jump to: navigation, search NASA Logo Listen to this article · (info) This audio file was created from the revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... Unmanned space missions are those using remote-controlled spacecraft. ... The Apollo Guidance Computer (AGC) was the first recognizably modern embedded system, used in real-time by astronaut pilots to collect and provide flight information, and to automatically control all of the navigational functions of the Apollo spacecraft. ... Jump to: navigation, search The Massachusetts Institute of Technology, or MIT, is a research and educational institution located in the city of Cambridge, Massachusetts, USA. MIT is a widely renowned leader in science and technology, as well as in many other fields, including engineering systems, management, economics, linguistics, political science... Jump to: navigation, search Raytheon Company NYSE: RTN is a major United States military contractor based in Waltham, Massachusetts. ...

Contrary to ordinary coincident-current magnetic core memory, which was used for RAM at the time, the ferrite cores in a core rope are just used as transformers. The signal from a word line wire passing through a given core is coupled to the bit line wire and interpreted as a binary "one" while a word line wire that bypasses the core is is not coupled to the bit line wire and is read as a "zero". In the AGC, up to 64 wires could be passed through a single core. A 16×16 cm area core memory plane of 128×128 bits, i. ... Jump to: navigation, search Random access memory (sometimes random-access memory), commonly known by its acronym RAM, is a type of computer storage (in practice only computer chips) whose contents can be accessed in any (i. ... Jump to: navigation, search Ferrites are ferromagnetic ceramic materials, compounds of iron, boron and barium or strontium or molybdenum. ... Jump to: navigation, search A transformer is an electrical device that transfers energy from one electrical circuit to another by magnetic coupling but without any moving parts. ... In computing, word is a term for the natural unit of data used by a particular computer design. ... Jump to: navigation, search This article is about the unit of information. ... The binary or base-two numeral system is a system for representing numbers in which a radix of two is used; that is, each digit in a binary numeral may have either of two different values. ...

For its time, a relatively large amount of data could be stored in a small installed volume of core rope memory—72 kilobytes per cubic foot (roughly 2.5 megabytes per cubic meter)—about 18-fold* the amount data per volume compared to standard read-write core memory. Jump to: navigation, search A kilobyte (derived from the SI prefix kilo-) is a unit of information or computer storage equal to either 1024 or 1000 bytes. ... The cubic foot (symbols ft³, cu. ... This article is about a unit of data measurement. ... Jump to: navigation, search The cubic metre (symbol m³) is the SI derived unit of volume. ...

Note: * The use of a 16-bit word length as a capacity/density measure in this table stems from the memory word length of the Apollo Guidance Computer, the most prominent "core rope machine", the Block II AGC used 36,864 words of core rope memory (1 cubic foot) and 4,096 words of magnetic core memory (2 cubic feet). Other machines will have somewhat different ratios between the two memory types.

Jump to: navigation, search A kilobyte (derived from the SI prefix kilo-) is a unit of information or computer storage equal to either 1024 or 1000 bytes. ... The megabit is a unit of information storage, abbreviated Mbit or sometimes Mb. ... This article is about a unit of data measurement. ... A kilobit is a unit of information storage, abbreviated kbit or sometimes kb. ... In computing, word is a term for the natural unit of data used by a particular computer design. ...

External links

• Photos of core rope memory and its production – By Raytheon; hosted by the Dibner Institute for the History of Science and Technology
• Computers in Spaceflight: The NASA Experience – By James Tomayko (Chapter 2, Part 5, "The Apollo guidance computer: Hardware")