Dynamic random-access memory: Difference between revisions

Content deleted Content added
No edit summary
No edit summary
Line 28:
 
=== Single MOS DRAM ===
In 1966, Dr. [[Robert Dennard]] invented invented modern DRAM architecture in which there's a single MOS transistor per capacitor,<ref name="ibm100">{{cite web |date=9 August 2017 |title=DRAM |url=https://www.ibm.com/ibm/history/ibm100/us/en/icons/dram/ |access-date=20 September 2019 |website=IBM100 |publisher=[[IBM]]}}</ref> at the [[IBM Thomas J. Watson Research Center]], while he was working on MOS memory and was trying to create an alternative to SRAM which required six MOS transistors for each [[bit]] of data. While examining the characteristics of MOS technology, he found it was capable of building capacitors, and that storing a charge or no charge on the MOS capacitor could represent the 1 and 0 of a bit, while the MOS transistor could control writing the charge to the capacitor. This led to his development of the single-transistor MOS DRAM memory cell.<ref>{{cite web |title=IBM100 — DRAM |url=https://www.ibm.com/ibm/history/ibm100/us/en/icons/dram/ |website=IBM |date=9 August 2017}}</ref> He filed a patent in 1967, and was granted U.S. patent number [https://web.archive.org/web/20151231134927/http://patft1.uspto.gov/netacgi/nph-Parser?patentnumber=3387286 3,387,286] in 1968.<ref>{{cite web |title=Robert Dennard |url=https://www.britannica.com/biography/Robert-Dennard |website=Encyclopedia Britannica|date=September 2023 }}</ref> MOS memory offered higher performance, was cheaper, and consumed less power, than magnetic-core memory.<ref name="computerhistory1970">{{cite web |title=1970: Semiconductors compete with magnetic cores |url=https://www.computerhistory.org/storageengine/semiconductors-compete-with-magnetic-cores/ |website=[[Computer History Museum]]}}</ref> The patent describes the invention: "Each cell is formed, in one embodiment, using a single field-efiiect transistor and a single capacitor."<ref>{{Cite patent|number=US3387286A|title=Field-effect transistor memory|gdate=1968-06-04|invent1=Dennard|inventor1-first=Robert H.|url=https://patents.google.com/patent/US3387286A}}</ref>
 
MOS DRAM chips were commercialized in 1969 by Advanced Memory Systems, Inc of [[Sunnyvale, California|Sunnyvale, CA]]. This 1024 bit chip was sold to [[Honeywell]], [[Raytheon]], [[Wang Laboratories]], and others.