> Whether or not that happens regularly, I'm not really sure.
All older machines (e.g. PowerPC Macs) mapped the I/O ports to an area of the "regular" address space. They probably still do it for legacy reasons. I think only s390 got rid completely of I/O ports because they never implemented PCI, only PCIe.
All older machines (e.g. PowerPC Macs) mapped the I/O ports to an area of the "regular" address space. They probably still do it for legacy reasons. I think only s390 got rid completely of I/O ports because they never implemented PCI, only PCIe.