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SubjectRe: Encrypted Swap
On Fri, 17 Aug 2001, Holger Lubitz wrote:

> "Richard B. Johnson" proclaimed:
> > Errrm no. All BIOS that anybody would use write all memory found when
> > initializing the SDRAM controller. They need to because nothing,
> > refresh, precharge, (or if you've got it, parity/crc) will work
> > until every cell is exercised. A "warm-boot" is different. However,
> > if you hit the reset or the power switch, nothing in RAM survives.
> Then this may have changed with SDRAM. However, back in my Amiga days it
> was pretty common to just reset the machine and rip whatever was left in
> the memory (DRAM). If memory serves me right, some people put in reset
> protection (by pointing the reset vector to some code that cleared the
> memory), which could be fooled by hardware reset or power cycling.

My Apple IIc's manual recommended waiting 15 seconds before turning the
machine back on in order to wait for the memory to clear. I wonder how
long SDRAM lasts if actually removed instead of letting the BIOS clear it
on boot.


Gerhard Mack

<>< As a computer I find your faith in technology amusing.

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