Thanks for the reply. The circuit works great. I even hooked up relays to control fans (clamped with diodes).

Unfortunately, a piece of metal got stuck to the circuit board and shorted two of the GPOs together. One of them burned out, so now I only have 5 working GPOs. I'm wondering why it burned ...

I have a BLK-202A, which has 6 low power GPOs. The manual says they're ground controlled, 20mA max with 240 ohm current limiting resistors.

I'm planning to use this ( http://www.lcdforums.com/forums/viewtopic.php?t=1036 ) to connect two fans to my GPOs. Would it matter if I used 5.6k resistors ...