On Wed, Oct 10, 2001 at 03:32:09AM -0500, Michael S. Zick wrote: > > Old ISA boards only do a 10-bit decode and it is a frequent occurance > that old drivers don't "clean up" the unused high 6 bits. > > Would it be reasonable to mask port numbers to 10 bits for ISA in the > inb/outb routines? No. Some old ISA boards do decode the top bits, and actually use them.