Re: [gentoo-user] Writing to a 256MB Rom

[Ryan Holt]

Okays. So assuming it's NVRAM, is that something that I'm likely going to be
able to write to without some type of equipment?

On 3/1/06, Toby 'qubit' Cubitt <tsc25@××××××.net> wrote:
>
> On Wed, Mar 01, 2006 at 04:16:33PM -0500, Ryan Holt wrote:
> > Is there any difference between ROM and NVRam?
>
> Yes. ROM is a WORM medium (write once, ready many times). The data
> stored in a PROM (programmable read only memory) is literally burned
> in by applying high-voltage pulses to the chip.
>
> There's also EPROM (eraseable PROM) which can be erased by exposing
> the chip to ultraviolet light, and EEPROM (electrically eraseable
> PROM). If we're being pedantic, ROM is a misnomer for these, since
> they're not really "write once".
>
> NVRAM (non-volatile random access memory) is similar to EEPROM in some
> ways: it can be written and erased many times, and maintains its data
> even when power is disconnected. MRAM, FRAM, etc. are forms of
> NVRAM. Flash memory is I believe a more modern form of EEPROM. They
> all differ in the physical technology used on the chip, and have
> different properties, such as how many times the memory can be erased
> and rewritten, how fast writing and reading is, etc.
>
> Also, Wikipedia says:
>
> "...there is a convention to reserve the term EEPROM [for] byte-wise
> writable memories compared to block-wise writable flash memories."
>
> > I think I mis-spoke when I said ROM; because it's actually Non Volatile
> Ram.
>
> You *could* have meant PROM, but NVRAM sounds much more likely ;-)
>
> Toby
> --
> PhD Student
> Quantum Information Theory group
> Max Planck Institute for Quantum Optics
> Garching, Germany
>
> email: toby@××××××××.org
> web: www.dr-qubit.org
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> gentoo-user@g.o mailing list
>
>