><< does anyone know what voltage(s) the linkport operates at? >> > >+5V non-active, 0V active Keep in mind that it uses a totem-pole type driver, so it's only +5V when there's absolutely zero current flow. With as low as 0.5 milliamp currently flow, the output drops to 0V even when it's in the non-active state. This is why you can short the output to ground and it won't ruin the linkport. -Mel