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Wednesday, March 9, 2011

Laptop BIOS password recovery using a simple dongle - Hack a Day

Laptop BIOS password recovery using a simple dongle

posted Mar 8th 2011 1:02pm by Mike Nathan
filed under: laptops hacks, security hacks


In his line of work, Instructables user [Harrymatic] sees a lot of Toshiba laptops come across his desk, some of which are protected with a BIOS password. Typically, in order to make it past the BIOS lockout and get access to the computer,  he would have to open the laptop case and short the CMOS reset pins or pull the CMOS battery. The process is quite tedious, so he prefers to use a simpler method, a parallel loopback plug.

The plug itself is pretty easy to build. After soldering a handful of wires to the back of a standard male D-sub 25 connector in the arrangement shown in his tutorial, he was good to go. When a laptop is powered on with the plug inserted, the BIOS password is cleared, and the computer can be used as normal.

It should be said that he is only positive that this works with the specific Toshiba laptop models he lists in his writeup. It would be interesting to see this tried with other laptop brands to see if they respond in the same way.
Since no laptops are manufactured with parallel ports these days, do you have some tips or tricks for recovering laptop BIOS passwords? Be sure to share them with us in the comments.

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Go there...

Toshiba Laptop BIOS Reset Dongle

Toshiba Laptop BIOS Reset Dongle
So you've got an old Toshiba Satellite (full list of compatible models at the bottom), turned it on and to your aggravation you are greeted with a Password prompt. While there are several ways to go about removing the password, I chose to build a very simple dongle device which connects to the parallel port - known in the trade as the Loopback Plug . When connected to the computer and the machine is started up, it will erase the contents of the BIOS back to factory defaults, taking out the password.

List of compatible models:
100 (1xx)
200 (2xx)
300 (3xx)
400 (4xx)
500 (5xx)
600 (6xx)
700 (7xx)
1000 (1xxx)
2000 (2xxx)
3000 (3xxx)
4000 (4xxx)
7000 (7xxx)
8000 (8xxx)

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Step 1Assembly

You will need the following:
1. A male D-sub 25 connector (or alternatively you could just stick the wires into the parallel port directly)
2. Assorted wire

And that's it! You can get both of these things by taking apart an old LPT printer cable which can probably be got for nothing.

The wiring diagram is shown in picture 2, it is as follows :
1-5-10, 2-11, 3-17, 4-12, 6-16, 7-13, 8-14, 9-15 (and 18-25 optional)

You might like to attach a plastic case to the plug to prevent accidental damage in case you intend on doing a lot of password forgetting.

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Allot of us still like to keep Our Good "Old" Machines Running and useful. That's one of the main reasons I got into Linux 6 years ago... I still don't even own a Laptop, #1 because they are just too expensive for what you really get. And #2, for me, the screens are just too small for me to read! I would need a 17 inch just to be able to read the thing for more than an hour without getting a huge eye strain head ache. And that's with glasses!:O Interesting Article:)



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