Abstract: An interface is provided that allows testing and using in-line memory modules in computer systems not designed for the modules. In particular, an interface of the present invention comprises an interposer card that fits into a motherboard memory module connection of a computer system. The interposer card also has a motherboard memory module connection system into which a memory module fits. Additionally, the interposer card contains a detection device that describes the configuration of the memory module. This allows the computer system to properly access the memory module. When used as part of a computer system, the interface allows memory modules to be tested by a memory diagnostics program. Moreover, the interface may be placed in any slot in the computer, even though the memory module itself only supports being placed in one particular slot.