Host independent peripheral controller with on-board firmware

A system supporting the selection between multiple images of a BIOS extension provided on a peripheral adapter for use in initialization of said peripheral adapter by a host computer specific to the processor type employed by said host computer, said system comprising:

• a) a peripheral adapter;
• and
• b) a BIOS extension provided on said peripheral adapter including a plurality of BIOS extension variant images that are separately executable by either a first or a second host computer that potentially employ different types of processors to perform peripheral adapter BIOS extension location and execution of an initialization routine provided within said variant images, at least one of said variant images including a nominal identifier of a BIOS extension and a firmware marker compliant with the location and execution of a predetermined legacy BIOS extension by said first host computer and that is distinguished by said second host computer as defining an unusable BIOS extension.