Originally Posted by GreenBeast
Sorry, but we need a little more information.
What signal is present on the wire coming from the alarm that will signal the computer to start.
And when you say "so that when i dis-arm the alarm it boots the PC and vice versa" do you mean that when you boot the computer, it will disarm the alarm (vice versa means the reverse, so since the alarm starts the computer, the computer starts disarms the alarm) I bet not, just want to confirm, some people have interesting ideas about what the ocmputer should/can do?
Most likely you will need some sort of diode to isolate the alarm from the "second" switch so that when used, it does not affect the alarm, but more information is needed.