grinding down chips was Re: QX10 graphics board - test-drb@ccmp.vtda.org

30 Jan 2006

...
 From: "Gordon JC Pearce" <gordonjcp at
gjcp.net>

Philip Pemberton wrote:
  In message <3.0.6.16.20060127101019.441734dc
at pop-server.cfl.rr.com>
           "Joe R." <rigdonj at cfl.rr.com> wrote:

    You'd probaly better with battery backed
RAM that would lose it power
(and contents) when it was removed from the circuit. Or else redisign and
use a PAL or some form or programmable logic that has a security fuse to
prevent it from being read.  

 Problem is, SRAM has this annoying tendency of storing data for a really long
 time if it's frozen beforehand.
 It also tends to "remember" data bits that have been stored in the memory
 cells without any writes for a long time. 
That's why the encryption cards banks use for ATMs detect when they get 
below a certain temperature, and overwrite the RAM.

Gordon 
Hi
 Often times the newer SRAM use SOI technology. These tend
to power on with the opposite value that they were programmed
with. The data looks scrambled but just inverting the values
will recover a large percentage.
Dwight