What you need is a Parallel Port switch...Go to http://www.tigerdirect.com/applications/SearchTools/item-details.asp?sku=C184-4006 ... All you will need to do is to install the printer drivers on both computers and the switch will auto-sense everything...It is fairly easy to do...

hope this helps
luke

You could try to hook up an A/B switch box. If you are using Parallel (IEEE-1284) you will need to buy the cables and match up the pin configurations. Hook up both computers to the switch box and select A or B to initiate the print job on the selected computer.

FYI: I use an A/B switch box to hook up two computers to one monitor using an SVGA switch box. I just select the computer that I want to work with on the switch box. It saves buying two SVGA monitors.

Hope this helps.