| PRAM uses the unique behavior of chalcogenide glass, which can be "switched" between two states, crystalline and amorphous, with the application of heat.Flash memory, which has a number of practical problems these replacements hope to address.Background
2 PRAM vs.Flash
3 Reset PRAM on Apple Computers
4 2000 and later
5 Fundamental tradeoff: unintentional vs.Background
The properties of chalcogenide glasses were first explored as a potential memory technology by Stanford Ovshinsky of Energy Conversion Devices in the 1960s.The amorphous, high resistance state is used to represent a binary 0, and the crystalline, low resistance state represents a 1.Although PRAM has not yet reached the commercialization stage for consumer electronic devices, nearly all prototype devices make use of a chalcogenide alloy of germanium, antimony and tellurium (GeSbTe) called GST.C), at which point the chalcogenide becomes a liquid.By heating the chalcogenide to a temperature above its crystallization point, but below the melting point, it will transform into a crystalline state with a much lower resistance.This phase transition process can be completed in as quickly as five nanoseconds, according to a January 2006 Samsung Electronics patent application concerning the technology.This is comparable to conventional volatile memory devices, for instance, modern DRAM cells have a switching time on the order of two nanoseconds.Flash
It is the switching time that makes PRAM, and other replacements for flash memory, most interesting.PRAM's temperature sensitivity is perhaps its most notable drawback, one that may require changes in the production process of manufacturers incorporating the technology.Flash memory works by modulating charge (electrons) stored within the gate of a MOS transistor.The gate is constructed with a special "stack" designed to trap charges (either on a floating gate or in insulator "traps").The presence of charge within the gate shifts the transistor's threshold voltage, higher or lower, corresponding to a 1 to 0, for instance.Changing the bit's state requires removing the accumulated charge, which demands a relatively large voltage to "suck" the electrons off the floating gate.This burst of voltage is provided by a charge pump which takes some time to build up power.PRAM can offer much higher performance in applications where writing quickly is important, both because the memory element can be switched more quickly, and also because single bits may be changed to either 1 or 0 without needing to first erase an entire block of cells.With Flash, each burst of voltage across the cell causes degradation, so most flash devices are only rated for something on the order of 10 000 to 100 000 writes per sector, and many flash controllers perform wear levelling to spread writes across many physical sectors.PRAM devices degrade with use, for different reasons than Flash.PRAM lifetime is limited by mechanisms such as degradation due to GST thermal expansion during programming, metal (and other material) migration, and other mechanisms still unknown.The contents of a PRAM, however, are lost because of the high temperatures needed to solder the device to a board in a wave solder machine.By carefully modulating the amount of charge stored on the gate, Flash devices can store multiple (usually two) bits in each physical cell.This effectively doubles the memory density, reducing cost.PRAM devices developed to date store only a single bit in each cell.Because Flash devices trap electrons to store information, they are susceptible to data corruption from radiation, making them unsuitable for many space and military applications.PRAM exhibits higher resistance to radiation.PRAM cell selectors can use various devices: diodes, BJTs and MOSFETs.Using a diode provides the greatest amount of current for a given cell size.The difference in leakage current is several orders of magnitude.Reset PRAM on Apple Computers
To reset the PRAM on Apple Computers, startup the computer and press: "Option+Command+P+R" at the same time.Instead, a very small platter coated in chalcogenide is dragged beneath many (thousands or even millions) of electrical probes which can read and write the chalcogenide.The announcement was something of a surprise, and it was especially notable for its fairly high density.Flash devices currently available.The high density of this prototype PRAM device suggests that it could be a real Flash competitor, and not limited to niche roles as these other devices have been.NAND flash can only be accessed in "banks" of many bytes at a time), which has generally lagged NAND densities and appears to be about the same density as this PRAM device.Intel is already the leading NOR Flash producer, and appears to be aiming their PCM at the same market as Samsung.Additionally, BAE claims a write cycle endurance of 108, which will allow it to be a contender for replacing PROMs and EEPROMs in space systems.Fundamental tradeoff: unintentional vs.Thermal conditions which allow for fast crystallization should not be too similar to standby conditions, e.Energy Conversion Devices, Inc.This page was last modified 21:19, 10 January 2008.All text is available under the terms of the GNU Free Documentation License.See Copyrights for details.Originally from Yorkshire, Rosie Cuckston and Matt Eaton went to school together.Along with drummer Andy Weir, the three then moved to Birmingham in the late 80's.They began gigging under the name Hole in 1988.Matt Eaton later joined the band playing multiple instruments.Cuckston's eerie vocals and lyrics dealing with depression, loneliness and the dark side of childhood.NME, which the band saw as a compliment.However, in 2004, NME tipped Pram as the next big band to watch out for.Unfortunatley this was untrue as Pram are still unpopular.The first album for Domino, North Pole Radio Station, was originally recorded for Wurlitzer Jukebox Records, but the label shut down before it could be released.Pram have been remixed by several artists (Somniloquy features remixes by fellow Brummie experimentalists Plone and Tele:funken amongst others), and remixed LFO and the Aphex Twin for the Warp Records 10th anniversary compilation.Their old drummer Steve Perkins had also been part of fellow brummie band Broadcast but soon left them also.Grandmaster Gareth of Misty's Big Adventure produced the string arrangement on 'Peepshow' from the album 'Dark Island'.He also arranged all the strings on the album 'The Moving Frontier' and played the cello on 'The Empty Quarter' and 'Compass Rose'.Matt Eaton is currently DJing with Mark from Plone for Silver Dollar, a reggae club in Birmingham.External links
Pram's Official Website
Official MySpace Page
Unofficial Website
Fansite
Interview at musicOMH.This page was last modified 02:38, 2 January 2008.All text is available under the terms of the GNU Free Documentation License.AAM Conference in Chicago.Advertisement
10 results for: pram
(Browse Nearby Entries)
pral
pralidoxime
praline
pralines
pralltriller
pralltrillers
PRAM
pramipexole
PRAMIS
PRAMS
PRAMU
PRAN
prana
pranava
pranayama
prance
pranced
prancer
prances
prancing
prancingly
Pram AccessoriesBargain Prices.Save on Pram Accessories!Sponsored LinksPramesMove your career forward with an accredited online degree!Pram StrollerGreat deals on everything Stroller themed.MD prame, praem (cf.Published by Houghton Mifflin Company.Published by Houghton Mifflin Company.Share This
PRAM hardware 1.Lexico Publishing Group, LLC.Advertisement
10 results for: PRAM
(Browse Nearby Entries)
pral
pralidoxime
praline
pralines
pralltriller
pralltrillers
PRAM
pramipexole
PRAMIS
PRAMS
PRAMU
PRAN
prana
pranava
pranayama
prance
pranced
prancer
prances
prancing
prancingly
Pram AccessoriesBargain Prices.Save on Pram Accessories!Sponsored LinksPramesMove your career forward with an accredited online degree!Pram StrollerGreat deals on everything Pram Stroller themed.MD prame, praem (cf.PushchairGet Great Deals Shopping Online Compare, Shop, and Save!Shortening and alteration of perambulator.Published by Houghton Mifflin Company.Published by Houghton Mifflin Company.Share This
PRAM hardware 1.Shop for books, music and more
Reference.Lexico Publishing Group, LLC.PRAM was originally founded in 1989 as an Underwriter and a Registered Administrator with corporate headquarters located in the City of Brea in Orange, California and today has offices in Chicago and throughout the US.PRAM provides Pharmacy Consulting, Underwriting and Employee Benefit services to local, regional and national accounts.We believe our experience in all aspects of Risk Management Consulting, including the understanding of Pharmacy Risk with the support of Staff Pharmacists will add value in providing strategic planning in a growing complex industry.Our goals are to help our clients understand and manage issues relating to medical and pharmacy claim cost while providing leading edge technology to analyze options that will have a positive impact on rising trends while balancing the needs of appropriate therapy.PRAM's Underwriting Staff and Pharmacy team brings years of experience in working with many of the nations leading insurance companies, national consultants, pharmacy benefit managers, and employer groups."Are you sure you want to block this user?Record LabelDomino Recording Company Ltd.Pram craft fairytales from concrete reality.Victoriana, tropical analogue and tumbledown funk.Born of an aesthetic universe where the senses are excited equally by the dust encrusted revolutions of antique lounge LPs as the wild and wonderful facts packing the yellowed pages of musty encyclopaedias, where a nostalgia for the future meets a fascination for a past that never was, Pram are drawn to the fantastic and exotic ends of the ordinary world.With Pram as your guide, armchair adventuring has never been so mysterious, beguiling or enticing.Toast on jamDear friends, You have very nice music.Friday then see you sometime in mid 08 !Very much enjoying the new album, and the article in last months Wire.Very much like that song.UBiK present:A Very UBiK XmAS featuring:ZOMBIE ZOMBIE with Mirror!To A Family FunctionEverybody loves a Family Occassion!Dress in your sunday best and bring your grandparents for yet another social catastrophy with KateGoes....Hello Pramyou write great music!Your last album is realy brilliant!You may have recently lost your shadows.Hi Pram,Thanks for being friends and for making so lovely music.This could be an attempt to steal your username and password.This information should not be considered complete, up to date, and is not intended to be used in place of a visit, consultation, or advice of a legal, medical, or any other professional.This document explains how to reset the parameter random access memory (PRAM) and nonvolatile RAM (NVRAM) on Macintosh computers.Important:
If your computer does not retain parameter RAM (PRAM) settings when it is turned off, this generally indicates that the battery needs to be changed.Your computer's PRAM and the NVRAM are reset to the default values.In some troubleshooting situations, if resetting PRAM does not resolve an issue, resetting the PMU may be the next appropriate step.Resetting PowerBook and iBook Power Management Unit (PMU).Some Macintosh computers may not have all the settings described below.Mac OS X: What's Stored in PRAM?Report typos, inaccuracies, etc. |
