Editing Bubble memory (section)

=== Commercialization ===
[[File:TI TIBS0004 bubble memory device (18997455749).jpg|thumb|upright=.75|Bubble Memory by [[Texas Instruments]]]]
[[file:KL Bubble Memory MemTech.jpg|thumb|upright=.75|Bubble memory by MemTech (purchaser of Intel Magnetics). The long sequence of letters encodes a map of the defective storage loops in the memory.]]
[[file:KL USSR Bubble Memory.jpg|thumb|upright=.75|Bubble memory made in the [[USSR]].]]
[[File:Helix Labs bubble memory board for IBM PC, component side (19227474936).jpg|thumb|4 MBit [[expansion card]] for [[IBM XT]] with four Intel 7110]]
[[File:Bubble memory card for Apple II, component side (19146005122).jpg|thumb|1 MBit expansion card for [[Apple II]] and [[Apple IIe|IIe]] with one Intel 7110<ref>[http://michaeljmahon.com/Helix%20Apple%20Bubble%20Memory%20Manual.pdf User's manual]</ref>]]

Bobeck's team soon had {{convert|1|cm|in|abbr=on}} 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-performance market being the only one they could not serve.

The technology was included in experimental devices from Bell Labs in 1974.<ref>{{cite news |title=Computer-Memory Aid Devised |author=Stacy V. Jones |url=https://www.nytimes.com/1974/02/02/archives/computermemory-aid-devised-patents-of-the-week-special-to-the-new.html |archive-url=https://web.archive.org/web/20180112042433/https://www.nytimes.com/1974/02/02/archives/computermemory-aid-devised-patents-of-the-week-special-to-the-new.html |archive-date=2018-01-12 |newspaper=New York Times |location=New York, N.Y. |issn=0362-4331 |date=Feb 2, 1974 |page=37 }}</ref> By the mid-1970s, practically every large electronics company had teams working on bubble memory.<ref>{{cite news |title=Technology: A Test for Magnetic Bubble Memories |author=Victor K. McElheny |url=http://www.nytimes.com/1977/02/16/archives/technology-a-test-for-magnetic-bubble-memories.html |archive-url=https://web.archive.org/web/20180111224132/http://www.nytimes.com/1977/02/16/archives/technology-a-test-for-magnetic-bubble-memories.html |archive-date=2018-01-11 |newspaper=New York Times |location=New York, N.Y. |issn=0362-4331 |date=Feb 16, 1977 |pages=77 |quote=Among manufacturers of magnetic bubble units, besides Bell Labs and I.B.M., are Texas Instruments, the Honeywell Inc. process control division in Phoenix, and Rockwell International... |url-status =dead }}</ref> Texas Instruments introduced the first commercial product that incorporated bubble memory in 1977, and introduced the first commercially available bubble memory, the TIB 0103 with 92 kilobit capacity.<ref>{{Cite web|url=https://books.google.com/books?id=GBRJAQAAIAAJ&q=texas+instruments+tib+0103|title=Canadian Electronics Engineering|date=March 3, 1978|publisher=Maclean-Hunter.|via=Google Books}}</ref><ref>{{Cite web|url=https://books.google.com/books?id=PUc7AAAAMAAJ&q=texas+instruments+tib+0103|title=Scientific American|date=March 3, 1977|publisher=Scientific American, Incorporated|via=Google Books}}</ref><ref>{{cite news |title=Texas Instruments Introduces Portable Computer Terminal: Model Said to Be First With Mass Memory and Using Bubble Memory Device |newspaper=Wall Street Journal |publisher=Dow Jones & Company Inc |location=New York, N.Y. |issn=0099-9660 |date=Apr 18, 1977 |page=13 }}</ref> By the late 1970s several products were on the market, and [[Intel]] released their own 1-megabit version, the 7110, in 1979.<ref>{{Cite web |url=https://books.google.com/books?id=f8kLXVsJ3J8C&dq=intel+7110+1979&pg=PA1 |title=Computerworld |first=I. D. G. |last=Enterprise |date=May 7, 1979 |publisher=IDG Enterprise |via=Google Books}}</ref><ref>{{Cite web |first=Paul |last=Freiberger |url=https://books.google.com/books?id=KTAEAAAAMBAJ&dq=intel+7110+1979&pg=PA28 |page=27-28 |title=Bubble memory is no longer the stuff of dreams |date=July 12, 1982 |publisher=InfoWorld|via=Google Books}}</ref><ref>{{Cite web|url=https://books.google.com/books?id=DT0EAAAAMBAJ&dq=intel+7110+1979&pg=PA1|title=One-Megabit Bubble Memory Commercially Available from Intel |date=May 9, 1979|publisher=InfoWorld |via=Google Books}}</ref> By the early 1980s, however, bubble memory technology became a dead end with the introduction of [[hard disk]] systems offering higher storage densities, higher access speeds, and lower costs. In 1981 major companies working on the technology closed their bubble memory operations,<ref>{{cite news |title=The Computer Bubble That Burst |first=Howard |last=Banks |url=https://www.nytimes.com/1981/09/20/business/the-computer-bubble-that-burst.html |newspaper=New York Times |date=September 20, 1981 |access-date=17 October 2013 |url-status=live |archive-url=https://web.archive.org/web/20150524082628/http://www.nytimes.com/1981/09/20/business/the-computer-bubble-that-burst.html |archive-date=24 May 2015 }}</ref><ref name="byte198205">{{Cite magazine |last1=Kocher |first1=Christopher P. |last2=Keith |first2=Michael |date=May 1982 |title=Six Personal Computers from Japan |url=https://archive.org/details/eu_BYTE-1982-05_OCR/page/n62/mode/1up?view=theater |access-date=2024-12-29 |magazine=BYTE |pages=61–102}}</ref> notably Rockwell, National Semiconductor, Texas Instruments and Plessey, leaving a "big five" group of companies still pursuing "second-generation bubble" by 1984: Intel, Motorola, Hitachi, [[SAGEM]] and [[Fujitsu]].<ref name="dataprocessing198410_bubble">{{ cite magazine |url=https://archive.org/details/sim_data-processing_1984-10_26_8/page/n27/mode/2up |title=Bubble memory in data processing |magazine=Data Processing |last1=Reece |first1=Charles |date=October 1984 |access-date=2 March 2023 |pages=26–28 }}</ref> 4-megabit bubble memories such as the Intel 7114, were introduced in 1983<ref>{{Cite book |url=https://books.google.com/books?id=2JI_AQAAIAAJ&q=intel+7114+1983 |title=Computer Design |date=1983 |publisher=Computer Design Publishing Corporation |language=en}}</ref><ref>{{Cite book |url=https://books.google.com/books?id=MGBJAQAAIAAJ&q=intel+7114+1983 |title=Electronics |date=1983 |publisher=McGraw-Hill Publishing Company |language=en}}</ref><ref>New Bubble-Memory Packaging Cuts Board Space And Manufacturing Costs. Intel AR-271. <!--http://www.wylie.org.uk/technology/bubblmem/7114.pdf--></ref> and 16-megabit bubble memory was developed.<ref>{{Cite web |url=https://books.google.com/books?id=pMUpAQAAMAAJ&q=hitachi+BDN0153 |title=Electronic Products Magazine|date=March 3, 1986 |publisher=United Technical Publications |via=Google Books}}</ref><ref>{{Cite web |url=https://books.google.com/books?id=mSpKAQAAIAAJ&q=Hitachi+BDN0151 |title=Journal of Electronic Engineering: JEE. |date=March 3, 1985 |publisher=Dempa Publications, Incorporated |via=Google Books}}</ref>

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 storage]], which also brought performance, density, and cost benefits.

One application was [[Konami]]'s [[Bubble System]] arcade video game system, introduced in 1984. It featured interchangeable bubble memory cartridges on a [[Motorola 68000|68000]]-based board. The Bubble System required a "warm-up" time of about 85 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 {{convert|30|to|40|°C|°F}} to operate properly. [[Fujitsu]] used bubble memory on their [[FM-8]] in 1981 and [[Sharp Corporation|Sharp]] used it in their [[Sharp PC-5000|PC 5000]] series, a laptop-like portable computer from 1983. Nicolet used bubble memory modules for saving waveforms in their Model 3091 oscilloscope, as did [[Hewlett-Packard|HP]] who offered a $1595 bubble memory option that extended the memory on their model 3561A digital signal analyzer. [[GRiD Systems Corporation]] used it in their early laptops. TIE communication used it in the early development of digital phone systems in order to lower their MTBF rates and produce a non-volatile telephone system's central processor.<ref>[http://oldcomputers.net/grid1101.html GRiD Compass 1101 computer] {{webarchive|url=https://web.archive.org/web/20080916202158/http://oldcomputers.net/grid1101.html |date=2008-09-16 }}, oldcomputers.net</ref> Bubble memory was also used on the [[Quantel Mirage]] DVM8000/1 VFX system.{{cn|date=June 2016}}

To store the bubbles, the propagation elements are in pairs and side to side, and are arranged in rows called loops to store the bubbles, thus they are storage loops since the bubbles that are stored in a loop will constantly circulate around it, forced by the rotating magnetic field that can also move the bubbles elsewhere. Bubble memories have extra spare loops to allow for increased yield during manufacturing as they replace defective loops. The list of defective loops is programmed onto the memory, on a special, separate loop called a boot loop, and it is also often printed on the label of the memory. A bubble memory controller will read the boot loop every time a bubble memory system is powered on, during initialization the controller will put the boot loop data in a boot loop register. Writing into a bubble memory is done by a formatter within the memory controller and signals from bits read in the bubble memory are amplified by the sense amplifier of the controller and they will reference the boot loop register to avoid overwriting, or further reading of the data in the boot loop.<ref name="intel"/>

The bubbles are created (the memory is written) with a seed bubble that is constantly split or cut by a hairpin-shaped piece of electrically conductive wire (such as aluminum-copper alloy) using a current strong enough to locally overcome and reverse the magnetic bias field generated by the magnets, thus the hairpin-shaped piece of wire acts as a small electromagnet. The seed bubble regains its original size quickly after cutting. The seed bubble circulates under a circular permalloy patch which keeps it from moving elsewhere. After generation, the bubbles then circulate into an "input track" and then into a storage loop. Old bubbles could be moved out of the loop into an "output track" for destruction later. The space left behind by the old bubbles would then be available for new ones.<ref name="intel"/> If the seed bubble is ever lost, a new one can be nucleated via special signals sent to the bubble memory and a current 2 to 4 times higher than necessary for cutting of bubbles from the seed bubble.<ref name="donald">{{Citation |last1=Rose |first1=DONALD K. |title=Chapter 4 - Technology and Manufacturing of High-Density Magnetic-Bubble Memories |date=1982-01-01 |url=https://www.sciencedirect.com/science/article/pii/B978012234104550010X |volume=4 |pages=147–181 |editor-last=Einspruch |editor-first=Norman G. |access-date=2023-09-07 |publisher=Elsevier |doi=10.1016/b978-0-12-234104-5.50010-x |last2=Silverman |first2=PETER J. |last3=Washburn |first3=HUDSON A.|series=VLSI Electronics Microstructure Science |isbn=9780122341045 |url-access=subscription }}</ref>

The bubbles in a storage loop (and empty spaces for bubbles) constantly circulate around it. To read a bubble, it would be "replicated" by moving it to a larger propagation element to stretch the bubble, then it would be passed under a hairpin-shaped conductor to cut it into two with a current pulse which lasts 1/4 of a hertz and is shaped as a spike waveform with a long trailing edge, this would split the bubble in two, one of which would continue circulating in the storage loop, keeping the bubble and thus data safe in case of power failure. The other bubble would be moved to an output track to move it to a detector which is a magnetoresistive bridge, made of a column of interconnected permalloy chevrons where the chevrons are one behind the other, and before it there are similar columns of chevrons that are not interconnected. These stretch the bubbles to generate a larger output at the detector. The detector has a constant electric current, and when bubbles pass under it, they change slightly the electrical resistance and thus current in the detector, and the movement of the bubbles creates a voltage in the order of millivolts, and this is read as either a 1 or a 0. Because the bubble must be moved to a specific area to be read, there are latency constraints. After the detector the bubbles are run into a guard rail to destroy them. A 1 is represented by a bubble, and a 0 is represented by the absence of a bubble.<ref name="intel"/>

The gadolinium gallium garnet wafers used as substrates for the bubble chips, were 3 inches in diameter and cost $100 each in 1982 as their production required the use of iridium crucibles.<ref name="donald"/>