A low-profile personal computer (PC) motherboard has memory modules mounted to an edge of the motherboard rather than mounted perpendicular using standard memory module sockets. The PC motherboard has a lower profile since memory module sockets are removed from the top surface of the PC motherboard. Expansion card sockets are also removed by integrating expansion functions into chips on the PC motherboard, or using an edge-mounted connector to the expansion card or to an external peripheral. Motherboard metal contacts are formed on an extended plug region near the edge of the PC motherboard. A first opening or slot of an edge connector fits over the motherboard metal contacts, while a second opening or slot of the edge connector fits over metal contacts on a standard memory module. The memory module and the PC motherboard each have printed-circuit boards (PCBs) that are in the same plane, thus reducing the overall height.