This application is directed to a system including a plurality of devices that are stacked one on top of another. Each device includes a substrate having two opposing surfaces. A first row of contacts is coupled on a first surface and includes a first contact and a second contact that are adjacent to each other. A second row of contacts is coupled on a respective second surface and includes a third contact. Each contact in the second row of contacts is physically aligned with an opposite contact in the first row. The third contact is disposed opposite and physically aligned with the first contact in the first row, and electrically coupled to the second contact in the first row. Operational circuitry is electrically coupled to at least the first contact on the first row, and at least two of the plurality of devices have distinct operational circuitry.