In article <20050724001536.GC32500@paradise.net.nz>, Volker Kuhlmann
<list0570@paradise.net.nz> writes

>> Unlike DRAM and SRAM, Flash etc. has no continual or repetitive
>> amplification function. Traces of previous charges may remain, but I
>> doubt they would be recoverable, except perhaps by the most drastic
>> forensic techniques
>
>I would expect flash memory content to be easily recoverable when
>opening the chip.

yes indeed ! there's remnants of charge left on the floating gates of
transistors, even after explicit attempts to erase; and they are
relatively straightforward to read out

have a look at Sergei Skorobogatov's research on this topic (and on data
remanence on semiconductors generally)

http://www.cl.cam.ac.uk/users/sps32/

--
richard Richard Clayton

They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety. Benjamin Franklin