A carrier module that is able to adapt non-standard instrument cards to the architecture of a test system is disclosed. Instrument cards based on non-standard architectures may be combined on a single carrier module. The carrier module is then plugged into the test head of the test system. The carrier module provides circuitry, contained on a plug-in sub-module called an Application Interface Adapter (AIA), to interface between the instrument cards and the test head interface connector. Additionally, the AIA may also provide access from the instrument cards to ATE system calibration circuitry. The carrier module uses the standard data bus of the test system for housekeeping and control functions. A second bus provides the bus for the non-standard instrument cards. Software drivers provided with the instrument cards are encapsulated with an appropriate wrapper so that the cards run seamlessly in the software environment of the test system.