FACTOID # 16: In the 2000 Presidential Election, Texas gave Ralph Nader the 3rd highest popular vote count of any US state.
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 


FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:



(* = Graphable)



Encyclopedia > Bubble memory

Bubble memory is a type of non-volatile computer memory that uses a thin film of a magnetic material to hold small magnetized areas, known as bubbles, which each store one bit of data. Bubble memory started out as a promising technology in the 1970s, but failed commercially as hard disk prices fell rapidly in the 1980s. Non-volatile memory, or non-volatile storage, is computer memory that can retain the stored information even when not powered. ... The terms storage (U.K.) or memory (U.S.) refer to the parts of a digital computer that retain physical state (data) for some interval of time, possibly even after electrical power to the computer is turned off. ... This article is about the unit of information. ... Typical hard drives of the mid-1990s. ...


Prehistory: Twistor memory

Bubble memory is largely the brainchild of a single person, Andrew Bobeck. Bobeck had worked on many kinds of magnetics-related projects through the 1960s, and two of his projects put him in a particularly good position for the development of bubble memory. The first was the development of the first magnetic core memory system driven by a transistor-based controller, and the second was the development of Twistor memory. A 16×16 cm area core memory plane of 128×128 bits, i. ... Assorted discrete transistors A transistor is a semiconductor device, the most common type of which acts as a current amplifier. ... Twistor is a form of computer memory, similar to core memory, formed by wrapping magnetic tape around a current-carrying wire. ...

Twistor memory was based on magnetostriction, an effect which can be used to move magnetic fields. If you place a pattern on a medium (for instance, magnetic tape) and then pass a current through the tape, the patterns will slowly be "pushed" down the tape while the patterns themselves will remain unchanged. By placing a detector at some point over the tape, the fields will pass under it in turn without any physical motion. In effect it is a non-moving version of a single track from a drum memory. In the 1960s AT&T had used Twistor in a number of applications. Magnetostriction is a property of ferromagnetic materials that causes them to change their shape when subjected to a magnetic field. ... Current (I) flowing through a wire produces a magnetic field () around the wire. ... Compact audio cassette Magnetic tape is a non-volatile storage medium consisting of a magnetic coating on a thin plastic strip. ... hi i am cool xbox is all most as cool as me hi again ... AT&T (NYSE: T) is the largest provider of both local and long distance telephone services, wireless service under the brand Cingular Wireless, and DSL Internet access in the United States. ...

Magnetic bubbles

In 1967 Bobeck joined a team at Bell Labs and started work on improving Twistor. He thought that if he could find a material that allowed the movement of the fields easily in only one direction, a sort of 2D Twistor could be constructed. Patterns would be introduced at one edge of the material and pushed along just as in Twistor, but since they could be moved in one direction only, they would naturally form "tracks" across the surface, increasing the areal density. Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) was the main research and development arm of the United States Bell System. ... Computer storage density is a measure of the quantity of information bits that can be stored on a given length of track, area of surface, or in a given volume; of a computer storage medium. ...

Starting with work on orthoferrite, Bobeck noticed an additional interesting effect: if an external field was applied to a magnetized patch of the material, the magnetized area would contract into a tiny circle, which he called a bubble. These bubbles were much smaller than the "domains" of normal media like tape, which suggested that very high densities were possible.

It took some time to find the perfect material, but they discovered that garnet turned out to have the right properties. Bubbles would easily form in the material and could be pushed along it fairly easily. The next problem was to make them move to the proper location where they could be read back out – Twistor was a wire and there was only one place to go, but in a 2D sheet things would not be so easy. The solution was to imprint a pattern of tiny magnetic bars onto the surface of the garnet. When a small magnetic field was applied, they would become magnetized, and the bubbles would "stick" to one end. By then reversing the field they would be attracted to the far end, moving down the surface. Another reversal would pop them off the end of the bar to the next bar in the line. Garnet is a group of minerals that have been used since the Bronze Age as gemstones and abrasives. ...

Five significant discoveries took place at Bell Labs: 1. The controlled two-dimensional motion of single wall domains in permalloy films. 2. The application of orthoferrites 3. The discovery of the stable cylindrical domain 4. The invention of the field access mode of operation 5. The discovery of growth-induced uniaxial anisotropy in the garnet system and the realization that garnets would be a practical material. The bubble system cannot be described by any single invention, but in terms of the above discoveries. Andy Bobeck was the sole discoverer of (4) and (5); he was the co-discoverer of (2) and (3); and (1) was performed in Bobeck's group under his direction and with many significant inputs from Andy. At one point, over 60 scientists were working on the project at Bell Labs, many of whom have earned recognition in this field. In September 1974, for instance, Dr. H.E.D. Scovil, working at Bell Labs in New Jersey, was awarded the Morris N. Liebmann Award by the IEEE with the following citation:"For the concept and development of single-walled magnetic domains (magnetic bubbles), and for recognition of their importance to memory technology."

A memory device is formed by lining up tiny electromagnets at one end with detectors at the other end. Bubbles written in would be slowly pushed to the other, forming a sheet of Twistors lined up beside each other. Attaching the output from the detector back to the electromagnets turns the sheet into a series of loops, which can hold the information as long as you like. An electromagnet is a type of magnet in which the magnetic field is produced by a flow of electric current. ...

Bubble memory is a non-volatile memory. Even when power was removed, the bubbles remained, just as the patterns do on the surface of a disk drive. Better yet, bubble memory devices needed no moving parts: the field that pushed the bubbles along the surface was generated electrically, whereas media like tape and disk drives required mechanical movement. Finally, because of the small size of the bubbles, the density was theoretically much higher than existing magnetic storage devices. The only downside was speed; The bubbles had to cycle to the far end of the sheet before they could be read. Non-volatile memory, or non-volatile storage, is computer memory that can retain the stored information even when not powered. ... Disk Drive is the afternoon show on CBC Radio Two. ...


Bobeck's team soon had 1 cm square memories that stored 4,096 bits, the same as a then-standard plane of core memory. This sparked considerable interest in the industry. Not only could bubble memories replace core, but it seemed that they could replace tapes and disks as well. In fact, it seemed that bubble memory would soon be the only form of memory used in the vast majority of applications, with the high-speed market being the only one they couldn't serve. This article is being considered for deletion in accordance with Wikipedias deletion policy. ... A 16×16 cm area core memory plane of 128×128 bits, i. ...

By the mid-1970s practically every large electronics company had teams working on bubble memory. By the late 1970s several products were on the market, and Intel released their own 1 megabit version, the 7110. In the early 1980s, however, bubble memory became a dead end with the introduction of higher-density, faster, and cheaper hard disk systems. Almost all work on it stopped. Intel Corporation (NASDAQ: INTC, SEHK: 4335), founded in 1968 as Integrated Electronics Corporation, is an American multinational corporation that is best known for designing and manufacturing microprocessors and specialized integrated circuits. ... Typical hard drives of the mid-1990s. ...

Bubble memory found uses in niche markets through the 1980s in systems needing to avoid the higher rates of mechanical failures of disk drives, and in systems operating in high vibration or harsh environments.

One application was Konami's Bubble System arcade video game system, introduced in 1984. It featured interchangeable bubble memory cartridges on a Z80-based board. Games available for the system included Gradius, Attack Rush/Hyper Crash/Hyper Crush (a racing game), and TwinBee. The Bubble System required a "warm-up" time of about 20 seconds (prompted by a timer on the screen when switched on) before the game was loaded, as bubble memory needs to be heated to around 30 to 40 °C to operate properly. The Bubble System did not prove popular, and many games originally available on the system were later released on other arcade boards with conventional ROM chips. Konami Corporation (コナミ) TYO: 9766 (NYSE: KNM) (SGX: K20) is a leading developer and publisher of numerous popular and strong-selling computer and video games. ... Konamis Bubble System was supposed to have a unique new form of data storage for arcade-style video games. ... 1984 (MCMLXXXIV) was a leap year starting on Sunday of the Gregorian calendar. ... The Zilog Z80 is an 8-bit microprocessor designed and manufactured by Zilog from 1976 onwards. ... The Gradius series, first introduced in 1985, is a series of scrolling shooter video games published by Konami for a variety of portable, console and arcade platforms, and has since its inception become synonymous with the phrase Shoot the core! []. In many games in the series the player controls a... Image from Detana! Twinbee. ...

Sharp used bubble memory in their PC 5000 series, a laptop-like portable computer from 1983. The word sharp or acronym SHARP has several uses: Look up sharp in Wiktionary, the free dictionary. ...

Further Applications

Interestingly, proposals using microfluidic bubbles as logic (rather than memory) have been recently proposed by MIT researchers. The bubble logic would use nanotechnology and has been demonstrated to have access times of 7 ms, which is faster than the 10 ms access times that present hard drives have, though it is slower than the access time of traditional RAM memory and of traditional logic circuits, making the proposal not commercially practical at present. [1]

External links

  • Great Microprocessors of the Past and Present. Appendix F: Memory Types – Web site by John Bayko
  • The Arcade Flyer Archive – Konami Bubble System Flyer

  Results from FactBites:
Bubble memory - Wikipedia, the free encyclopedia (966 words)
Bubble memory is a type of computer memory that uses a thin film of a magnetic material to hold small magnetized areas, known as bubbles, which each store one bit of data.
Bubble memory was a very promising technology in the 1970s, but flopped commercially when hard disks proliferated in the 1980s.
Bubble memory is largely the brainchild of a single person, Andrew Bobeck.
Bubble System - Wikipedia, the free encyclopedia (279 words)
It used bubble memory cartridges, a sort of non-mechanical magnetic storage system.
The reason this was implemented was because Bubble Memory had to be heated to around 40-50°C for it to work properly.
Bubble Memory was not a fully developed technology by the time it was used in the Bubble System, and as a result it is currently very rare to find a working Bubble System.
  More results at FactBites »



Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m