Assuming the PC is on, the output pins of the parallel port when set in an output state will be driving so if they are set low they will be sinking current, if set high they will be sourcing current. As vger posted, there are multiple setups for parallel ports and some of the setups the data lines can be bidirectional. Pullups or pulldowns on a device connected to the parallel port would come into play when the pc is off or disconnected. When the pc is on, termination of the lines for better transmission characteristics is normal.
Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
Vist my websites - http://pminmo.com & http://millpcbs.com