Patent ID: 6920517

Claim:
A removable first-level module for operation in a first slot of a portable host and in conjunction with at least a removable second-level module and a device external to the module, the removable first-level module comprising: an expansion module frame and an internal support structure for components; I/O interconnect; external-interface circuitry for providing first information transfers with the external device; a second slot for the removable second-level module; second-level module interface circuitry for providing second information transfers with the second-level module; and wherein the first-level module operatively couples to the external device via the I/O interconnect, the first information transfers include transferring information between the external device and the first-level module, the first and second slots are respectively, first-level and second-level slots, the first-level module operatively couples to the portable host via the first-level slot, the second-level module operatively couples to the first-level module via the second-level slot, and the second information transfers include transferring information between the first-level module and the second-level module.