Abstract: A system of ISA bus cards compatible with plug and play protocol stores common resource data in a plurality of programmable read only memories which are each installed on the individual bus cards. A random access memory is also provided on each one of the bus cards. In order to comply with the plug and play protocol, each of the random access memories is programmed independently from the read only memories with a unique identification that identifies the individual bus card. The separation of the storage location of the unique identification from the resource data common to all of the bus cards allows for mass production and programming of the read only memories, while still providing the unique identification for each bus card that is required by the plug and play protocol.