Abstract: A digital switching system is described for providing time division multiplexed digital communication of parallel sequential signals of N words each of M bit length between N telephone data subscribers over N transmission lines in which an array of orthogonal RAM memory devices provide parallel-to-serial conversion and multiplexing of the N words each of M bit length to provide a time division multiplexed serial digital bit stream of M words, each N bits in length, which are transmitted over a transmission line to a serial-to-parallel converter and coupled to a second orthogonal RAM memory device in which the N words M bits in length from the serial-to-parallel converter are stored and coupled to N telephone data subscribers over the transmission lines.