Is flash memory (like in SD,CF,SMC,etc. cards) magnetic? - Storage

This is a discussion on Is flash memory (like in SD,CF,SMC,etc. cards) magnetic? - Storage ; Is flash memory (like in SD,CF,SMC,etc. cards) magnetic? How close to a magnetic source would it have to get to be damaged. This hasn't happened to me yet personally, but what if it's laying on the floor and somebody vacuums ...

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Thread: Is flash memory (like in SD,CF,SMC,etc. cards) magnetic?

  1. Is flash memory (like in SD,CF,SMC,etc. cards) magnetic?

    Is flash memory (like in SD,CF,SMC,etc. cards) magnetic?
    How close to a magnetic source would it have to get to be damaged. This
    hasn't happened to me yet personally, but what if it's laying on the floor
    and somebody vacuums right next to it. That'd be a 10 amp motor right
    next to it. What about the old laying it on top of your monitor or phone
    thing, like used to happen back in floppy days?
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  2. Re: Is flash memory (like in SD,CF,SMC,etc. cards) magnetic?

    flash memory is used in the devices that you listed, eg, phones. so
    obviously, it wont be erased because of that.

    wrote in message
    news:t9kh91p7cjevkihaf6blji4jp25j65qnv1@4ax.com...
    > Is flash memory (like in SD,CF,SMC,etc. cards) magnetic?
    > How close to a magnetic source would it have to get to be damaged. This
    > hasn't happened to me yet personally, but what if it's laying on the floor
    > and somebody vacuums right next to it. That'd be a 10 amp motor right
    > next to it. What about the old laying it on top of your monitor or phone
    > thing, like used to happen back in floppy days?
    > --
    > __________________________________________________ ___
    > For email response, or CC, please mailto:see.my.sig.4.addr(at)bigfoot.com.
    > Yeah, it's really a real address




  3. Re: Is flash memory (like in SD,CF,SMC,etc. cards) magnetic?

    Flash memory uses capacitance not magnetism. As far as I know its
    impervious to most normal external electromagnetic raditation. You
    pretty much have to be in the circuit to change the voltage in the
    flash memory cells. The following is lousy physics, but I've tried to
    explain it as best I can. Both flash and magnetic storage are based on
    storing electrons. Magnetic memory is coerced (induced) into arranging
    electrons on the media a particular way through the electromagnetic
    fields generated by the by the recording heads. This arrangement of
    electrons gives the media the electromagnetic characteristics that
    allow the heads to identify data correctly when reading it. Strong
    external magnetic fields can also re-arrange the electrons, making them
    non-sensical to disk drive heads. Flash on the other hand is
    implemented as tiny capacitors in integrated circuits where electrons
    are deposited directly on whatever passes for capacitor plates in the
    silicon realm. The electrons stored are not in any particular
    arrangement, they are simply "piled up" there and once they are piled
    up, there is nowhere else for them to go until the circuit creates an
    inverse operation and drains them away. I think you could probably
    place flash memories in a cat scan (much less next to an industrial
    strength electric motor) and they would retain their data. No - I
    certainly haven't tried cat-scanning and don't advocate sneaking one in
    to check it out. I'm sure there are materials engineers and the like
    who could tell you what the tolerances are of these circuits to all
    kinds of EMI. Accidental or intentional microwaving does not qualify as
    a best practice. One last serious point - flash does wear out - the
    last time I checked it was around every million writes or so. OK for
    data archiving, perhaps a bit risky for transaction processing.


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