Maybe I missed it, but what Windows version are you using ? Some (the "built on NT technology") may have some problems with direct access to hardware, such as the printer port. That is, *if* not going throught the proper Windows API's. Now, I do *not* know if your programming software does that, but you seemed out of ideas, so... Jan-Erik Soderholm -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads