A microelectronic assembly can include a circuit panel having first and second surfaces and panel contacts at each surface, and first and second microelectronic packages having terminals mounted to the panel contacts at the first and second surfaces, respectively. The circuit panel can electrically interconnect terminals of the first package with corresponding terminals of the second package. Each package can include a substrate having first and second surfaces, a microelectronic element, conductive structure extending above a front face of the microelectronic element, and parallel columns of terminals at the second surface. The terminals of each package can include first terminals in a central region of the respective second surface and configured to carry address information usable by circuitry within the package to determine an addressable memory location within the respective microelectronic element. Each central region can have a width within three and one-half times a minimum pitch between adjacent terminals.