1. A unitary high density electronic module comprising: an integrated stack of glued together layers, a plurality of which are IC chips containing active signal-processing circuits; each IC chip having a multiplicity of electrical leads which extend from the IC circuitry of the chip to a common access plane formed by the integrated stack; a substrate layer extending in a plane perpendicular to the stacked IC chip layers, and secured to the access plane, the substrate layer having a multiplicity of electrical connections to separate leads on the access plane; said substrate layer being an IC chip containing active signal-processing circuits which interact with the circuitry in the stack to enhance the usefulness of the signals in the stack for interaction with circuitry external to the module.