List of compatible models:
Step 1: Assembly
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.
Step 2: Configuration
You will need to enter the BIOS setup facility to remove the password and save changes. In my case this was done by turning on the power with the plug still connected, whilst holding down the 'Esc' key. The system then prompted me to press F1 to enter setup. The password field should now say 'Not Registered'. Exit setup by pressing End to save changes.
That's it - you're done!