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. DDR SDRAM ( double data rate synchronous dynamic random access memory) is a class of memory Integrated circuit used in Computers It achieves nearly twice Static random access memory (SRAM is a type of Semiconductor memory where the word static indicates that unlike ''dynamic'' RAM (DRAM, it does not Z-RAM, short for " zero capacitor RAM " is a new type of Computer memory in development by Innovative Silicon Inc Twin Transistor RAM ( TTRAM) is a new type of Computer memory in development by Renesas The Williams tube or the Williams-Kilburn tube (after inventors Freddie Williams and Tom Kilburn) developed about 1946 or 1947 Genesis in radar The basic concept of the delay line originated with World War II Radar research as a system to reduce clutter from reflections from the ground Non-volatile memory, nonvolatile memory, NVM or non-volatile storage, is Computer memory that can retain the stored information A programmable read-only memory ( PROM) or field programmable read-only memory ( FPROM) is a form of digital memory where the setting of each bit is EEPROM (also written E2PROM and pronounced e-e-prom or simply e-squared which stands for E lectrically E rasable P rogrammable An EPROM, or E rasable P rogrammable '''''R'''ead-'''O'''nly '''M'''emory'', is a type of memory chip that retains its EEPROM (also written E2PROM and pronounced e-e-prom or simply e-squared which stands for E lectrically E rasable P rogrammable Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed Ferroelectric RAM ( FeRAM or FRAM) is a Random access memory similar in construction to DRAM but uses a Ferroelectric layer instead Magnetoresistive Random Access Memory ( MRAM) is a non-volatile computer memory ( NVRAM) technology which has been under development since The programmable metallization cell, or PMC, is a new form of non-volatile Computer memory being developed at Arizona State University and Phase-change memory (also known as PCM, PRAM, PCRAM, Ovonic Unified Memory, Chalcogenide RAM and C-RAM) is a type This article is about the music device manufacturer For the computer memory system see SONOS. Resistive random-access memory ( RRAM) is a new Non-volatile memory type being developed by Fujitsu, Sharp, Samsung, Micron IBM Racetrack Memory is an experimental Non-volatile memory device under development at IBM 's Almaden Research Center by a team led by Stuart Nano-RAM is a proprietary Computer memory technology from the company Nantero. Drum memory is a magnetic Data storage device and was an early form of Computer memory widely used in the 1950s and into the 1960s invented by Gustav Tauschek Magnetic core memory, or ferrite-core memory, is an early form of Random access Computer memory. Twistor is a form of Computer memory, similar to Core memory, formed by wrapping or closing Magnetic tape around a current-carrying wire Non-volatile memory, nonvolatile memory, NVM or non-volatile storage, is Computer memory that can retain the stored information A bit is a binary digit, taking a value of either 0 or 1 Binary digits are a basic unit of Information storage and communication Bubble memory started out as a promising technology in the 1970s, but failed commercially as hard disk prices fell rapidly in the 1980s. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device

Prehistory: twistor memory

Bubble memory is largely the brainchild of a single person, Andrew Bobeck. Andrew H Bobeck (October 1 1926 -) is a noted Bell Labs researcher best known for his invention of Bubble memory. 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. Magnetic core memory, or ferrite-core memory, is an early form of Random access Computer memory. In Electronics, a transistor is a Semiconductor device commonly used to amplify or switch electronic signals Twistor is a form of Computer memory, similar to Core memory, formed by wrapping or closing Magnetic tape around a current-carrying wire

Twistor memory was based on magnetostriction, an effect which can be used to move magnetic fields. Magnetostriction is a property of Ferromagnetic materials that causes them to change their shape when subjected to a Magnetic field. In Physics, a magnetic field is a Vector field that permeates space and which can exert a magnetic force on moving Electric charges If a pattern is placed on a medium (for instance, magnetic tape) and then a current is passed through the tape, the patterns will slowly be "pushed" down the tape while the patterns themselves will remain unchanged. Magnetic tape is a medium for Magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of Plastic. 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. Drum memory is a magnetic Data storage device and was an early form of Computer memory widely used in the 1950s and into the 1960s invented by Gustav Tauschek In the 1960s AT&T had used Twistor in a number of applications. Before proposing a merge request please see Talk and see if the merger you propose has recently been made and

Magnetic bubbles

In 1967 Bobeck joined a team at Bell Labs and started work on improving Twistor. Bell Laboratories (also known as Bell Labs and formerly known as AT&T Bell Laboratories and Bell Telephone Laboratories) is the Research organization 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. For computer memory comparisons see Computer storage density.

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. An orthoferrite is any of a class of Chemical compounds with the formula RFeO (where R is one or more Rare-earth elements. These bubbles were much smaller than the "domains" of normal media like tape, which suggested that very high densities were possible.

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) and 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. For instance, in September 1974, H.E.D. Scovil, working at Bell Labs in New Jersey, was awarded the IEEE Morris N. Liebmann Memorial 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. Dr Henry Evelyn Derrick Scovil, better known as H E D Scovil or Derrick Scovil, is a Physicist noted for his contributions to Masers and The IEEE Morris N Liebmann Memorial Award was established in 1919 by the Institute of Radio Engineers (now the Institute of Electrical and Electronics Engineers)

It took some time to find the perfect material, but they discovered that garnet turned out to have the right properties. The garnet group includes a group of minerals that have been used since the Bronze Age as gemstones and abrasives 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.

A memory device is formed by lining up tiny electromagnets at one end with detectors at the other end. An electromagnet is a type of Magnet in which the Magnetic field is produced by the flow of an electric current. 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.

Bubble memory is a non-volatile memory. Non-volatile memory, nonvolatile memory, NVM or non-volatile storage, is Computer memory that can retain the stored information Even when power was removed, the bubbles remained, just as the patterns do on the surface of a disk drive. Disk storage is a general category of a Computer storage mechanisms in which data is recorded on planar round and rotating surfaces ( disks, discs, or 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.

Commercialization

Bobeck's team soon had 1 cm square memories that stored 4,096 bits, the same as a then-standard plane of core memory. A centimetre ( American spelling: centimeter, symbol cm) is a unit of Length in the Metric system, equal to one hundredth Magnetic core memory, or ferrite-core memory, is an early form of Random access Computer 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.

Intel 7110 magnetic-bubble memory module

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. A hard disk drive ( HDD) commonly referred to as a hard drive, hard disk, or fixed disk drive, is a Non-volatile storage device Almost all work on it stopped.

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. This application became obsolete too with the development of flash memory, which also brought speed, density, and cost benefits. Flash memory is non-volatile computer memory that can be electrically erased and reprogrammed

One application was Konami's Bubble System arcade video game system, introduced in 1984. () is a leading developer and publisher of numerous popular and strong-selling toys Trading cards, Anime, Tokusatsu, Slot machines The Bubble System is an Arcade system board designed by Konami and utilized across many Arcade games in the early eighties Year 1984 ( MCMLXXXIV) was a Leap year starting on Sunday (link displays the 1984 Gregorian calendar) It featured interchangeable bubble memory cartridges on a 68000-based board. The Motorola 68000 is a 16/32-bit CISC Microprocessor core designed and marketed by Freescale Semiconductor (formerly Motorola Semiconductor Games available for the system included Galactic Warriors, Gradius, Konami RF2 (a racing game, also known as Konami GT), and TwinBee. is a horizontally-scrolling Shoot 'em up released by Konami in 1985 for Video arcades It was originally released in Europe as Konami GT (also known as Konami RF2 - Red Fighter) is a 1985 racing Videogame released by Konami, off their GX400 "Twinbee" redirects here For an overview of the TwinBee series see TwinBee (series. 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.

Sharp used bubble memory in their PC 5000 series, a laptop-like portable computer from 1983. () is a Japanese Electronics manufacturer founded in 1912 It takes its name from one of its founder's first inventions the Ever-Sharp Mechanical pencil, which The Sharp PC-5000 was a pioneering Laptop Computer, announced by Sharp Corporation of Japan in 1983

Nicolet used bubble memory modules for saving waveforms in their Model 3091 oscilloscope.

Further applications

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]

References

1. ^ Microfluidic Bubble Logic, Manu Prakash and Neil Gershenfeld, Vol. 315, Science, 9 Feb. 2007

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
• Bubbles: the better memory