Hi Ray A word of caution here - IO_BASE_ADDRESS only appears in the recent CVS sources. If you're running BDI-TNG or BDI-2.xx, then it is PARPORT_BASE_ADDRESS for the parallel port and STG_BASE_ADDRESS for the Serv To Go drivers. Regards, Paul. On Tuesday 02 Jul 2002 3:55 pm, Ray Henry wrote: > 1. IO_BASE_ADDRESS