Abstract: A memory module configured such that it can be operated as a first memory module such as a (Single In-line Memory Module) SIMM or as a second memory module such as a (Dual In-linc Memory Module) DIMM module without requiring external switching circuitry. This is accomplished by providing a memory module card with a circuit thereon that is designed to emulate a DIMM module when plugged into a DIMM socket as found in the latest computer architectures and to emulate a SIMM module when plugged into a SIMM socket as found in older computer architectures. The memory module is provided with memory devices (DRAMS or SDRAMS) and interconnecting bypass devices (CMOS transistor pairs) mounted thereon.