The Tektronix 73A-851A Adapter Module is a printed circuit board assembly for use in a card cage conforming to the VXIbus Specification. It allows A or B size VME modules, or A or B size VXIbus modules to be installed in a C-size card cage. The 73A-851A Module maintains the proper VMEbus environment, timing, and backplane line length by buffering the VME address bus, data bus, and control signals and routing them to the installed module.