October 18th, 2003, 07:57 AM
Build Your Own Electronic Key Card Lock
We have something a bit more advanced for you today to work on for you computer. This guide will allow you to replace your power button with a perforated coded card, giving the possibility to glockh your computer. People wonft be able to turn it on nor off via hardware. If you want to power up or shut down your PC, all you have to do is insert the card and take it out. The size of the coded card depends on the size of the materials and you. Ifve chosen to use an optic reading circuit together with a perforated card containing a code because all youfll see is a little slit wherever you put the reading circuit.
The reading circuit can be away from the circuit that is in charge of the lock. With a coded card you donft need to remember or type numbers compared to a numeric pad. Having only some ICs you can have a huge number of possible combinations. The circuit Ifm about to describe has 255 possible combinations, Ifve asked in the forums and this is what most people requested.
The Slashdot Article
The Key Card Lock With Complete Instructions and Materials List
http://www.gideontech.com/guides/electronic_lock/slcard.jpg The card reader and the card.
Of course it looks crude now but you can polish it up and make it a legitimate looking deal. Perhaps increase the number of holes and use a drill press to make clean cuts. I like the idea and thought it was interesting.