Actually it's not a very expensive project, i had to buy a buffer IC that cost me $1.50 and a parallel port connector. Seems you guys are interested in the how it works parts a bit too. There are 8 possible outputs and 5 possible inputs for a computer's parallel port, yes they are usually programmed in qbasic, however it's rather easily used in Visual Basic, so i can make a windows application with this stuff.

The relays will be the only real cost here, and yes i just want to monitor when voltage is applied, not control.

"SSAC makes a solid state relay that uses a 5Vdc input(actually 3-32Vdc) to switch a 120Vac output. I know they make a 10A and a 30A. They are pretty reliable with no moving parts to wear out and are very small."

Actually, i just need relay that works on a 120 or 220 input and switches a dc load, it needs to have two positions, not on and off because to a parallel port, ground and off are two different things. Nothing at all isn't a state and it will think it's not connected. The dc load current is next to nothing, it's in the single digit miliamps i believe.

I've already thought of dreaming up extentions to this project, although i haven't gotten the relays to finish the first part. I'm trying to think of a way to get my computer to run the thermostat, i just don't know how to get a temperature reading into my computer, otherwise i could monitor and set the temperature over the internet [Linked Image]