On Thu, Oct 25, 2007 at 11:40:50PM -0400, William Case wrote: > > On Thu, 2007-10-25 at 22:29 -0400, Charles MacDonald wrote: > > > BIOS is more or less customised to the Motherboard so it has in rom some > > idea of where to look for built in hardware. (keyboard etc. > > > Rhetorical question; how? The BIOS code is going to find the hardware by reading and writing to various well known i/o addresses. There is an unofficial semi-standard list of i/o addresses used. In the past the CPU had to do most of the system initialization. In modern computers the PCI and related buses have more inteligence. The PCI spec defines a simple discovery and initialization protocol that is largely handle in hardware by the PCI devices. -- sg