The Slot Manager/Configuration ROM architecture has two main goals in life. The first is to provide a mechanism to allow the user to insert a card in a slot and have the card be operational without having to set any switches, worry about which slot to put the card in, or install any special software.
The second goal is to free an application from being dependent on a particular type of hardware. That is, the goal is to allow an application to be insulated from the hardware by being able to locate underlying, intermediate driver software that will "know" about and talk to the specific hardware. This frees the application to be able to deal with higher level functions without being tied to a given set of hardware.
Both of these goals are accomplished via the slot manager software and the firmware data structures contained in the configuration ROMs of each card. If a valid configuration ROM is present, system software as well as applications and drivers can take advantage of the Slot Manager library of routines to meet the two goals stated above.