DeLL puts a 1-Wire=AE=99 ROM in the power brick as well in an attempt to bl=
ock unauthorized power adapters.  It's a funny little TO-92 device with one=
 of the pins cut off.  The reasons for going with through-hole over SMD whe=
n it would be the obvious choice in this case are a bit mysterious.  Maybe =
they got a good deal on them, who knows.

> Date: Wed, 12 Nov 2014 12:24:36 +1100
> From: quozl@laptop.org
> To: piclist@mit.edu
> Subject: Re: [EE]:: Securely encrypt your batteries with HMAC SHA-1
>=20
> On Wed, Nov 12, 2014 at 12:28:15AM +0000, Nicola Perotto wrote:
> >=20
> > On 11/11/2014 23:15, RussellMc wrote:
> > > 'This product is intended only for use with the high quality [tm] ove=
r-priced
> > > batteries sold by xxx corporation.' Which may be of merit in some cas=
es :-).
> > > For some values of 'merit' R=20
> >=20
> > My 5 years old D3ll notebook has already a very similar feature... in t=
he
> > charger: if it's not original you can charge the battery and the laptop=
 runs slowly.
> > They use a 1-wire 64 bit ID chip that has low security and can be
> > cloned :-)
>=20
> Same here.  We use a DS2756.  One of the EEPROM bytes contains our
> battery chemistry identifier.  Our charger firmware won't charge the
> battery unless that identifier matches one of the algorithms we have.
>=20
> Interesting things may happen if the identifier is wrong; 'cause we
> support NiMH as well as LiFePO4.
>=20
> We're adding LiPoly now.  I've been busily testing samples.
>=20
> http://dev.laptop.org/git/users/rsmith/ec-cl4_ras/log/?h=3Dlipoly
>=20
> --=20
> James Cameron
> http://quozl.linux.org.au/
> --=20
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> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
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