EEPROM Reader.

[Brett]

Hi,

I have an old Thinkpad R40 that I haven't used since 2007, which
shouldn't be a problem except that I have forgot the passwords and am
locked out. I have stripped
it down and found the ATMEL 24RF08 EEPROM on the board and now need to
make an EEPROM reader to get a dump of it so I can recover the
passwords.

The problem I am having is not in actually making the device, but in
figuring out which design to use. There is a design here that looks
good;

http://solve-pc.blogspot.com/2008/11/ibm-thinkpad-r40-supervisor-password.html

but I'm not sure if it would work and would like the opinion of
someone more skilled in electronics design. If anyone has successfully
extracted passwords from
a Thinkpad using this method your input - or EEPROM reader designs :)
- would be very welcome.

thanks,

Brett.

[Luke Weston]

I don't think there's anything wrong with that type of simple design
using an RS-232 port and bit-banging the I2C and using a couple of
resistors and diodes to limit the current and clamp the voltage... if
you've got a machine with a RS-232 port. They're getting hard to find
these days.

You could use an Arduino to talk over the I2C bus to the EEPROM, and
just plug the Arduino into USB.

To connect to the EEPROM IC, all you need is to have the EEPROM chip
powered up and have the two I2C bus wires connected to your read-out
circuit, plus a common ground between the two circuits.

To connect the I2C to an Arduino, you just connect it up - no other
electronics is required. There is plenty of Arduino documentation
relating to I2C serial EEPROMs.

http://www.arduino.cc/playground/Code/I2CEEPROM

http://www.arduino.cc/playground/Code/I2CEEPROM24LC512

http://arduino.cc/en/Tutorial/EEPROMRead

http://arduino.cc/en/Tutorial/EEPROMWrite
http://arduino.cc/en/Tutorial/EEPROMClear

[Brett]

Thanks Luke,

Looks like I will be learning about Arduino. I've never looked into it
or used it before so this could get interesting.

[Luke Weston]

Even better would be to drop around at a HackerSpace meeting and
borrow the BusPirate from Andy, that will be perfect for what you want
to do.

[andyg (geekscape)]

hi Brett,

The Bus Pirate is an interesting device, because of it's flexibility
when it comes to interacting with various chip level protocols, e.g
SPI, I2C, 1-wire, etc ...

http://buspirate.com

If you try ours out successfully, you might like to get one yourself.

Of course, there is nothing more satisfying than completely solving a
problem yourself.

If you bring your laptop along on to a HackerSpaces meeting, then
there are plenty of experienced people happy to help you ... and it's
more fun than via email. Just email me for location details.

cheers andyg (@geekscape)

[Mitch Davis]

Hi Brett,

On Mon, Oct 12, 2009 at 6:57 PM, Brett <baw...@student.monash.edu.au> wrote:
>
> Looks like I will be learning about Arduino. I've never looked into it
> or used it before so this could get interesting.

Come, you'll have fun.

In other news, you can also use the DDC channel on your video card to do I²C:

http://www.paintyourdragon.com/uc/i2c/index.html

(But the Arduino and/or the Bus Pirate would be easier and more fun)

Mitch.

[Brett]

Thank's guys'. Have emailed Andy to get the meeting details'.