id should be handled even through it's marked as disabled in POS registers. There are some cards which need this due to nonstandard hw design.
buses do - array of 'supported' peripheals makes addition of new stuff unnecessarily harder
This work is based on code written by Scott D. Telford, the IBM Token Ring card attachment was written by Gregory McGarry. XXX this is still very experimental and development version; use at your XXX own risk