A combined telecommunications and data communications system operates by partitioning data wherein the PCM speech transmission data field is used to contain both digitized speech and other data in the same channel within a frame. Thus the system enables speech and data to be combined in a common information field and to be simultaneously transmitted in the same channel, frame by frame, through a digital switching network. The system has a data base which is a computer coupled to a predetermined port of the switching network so that data transmitted from any subscriber can be received by the data base. The output of the data base is coupled to the tone bus so that the received data or the processed data from the data base can be coupled to any or all subscribers associated with the switching systems via the tone bus. This simultaneous broadcasting of data via the tone bus eliminates the need for additional channels in the switching network for transmitting data from the data base to subscribers. This advantage is realized by the use of the systems unique ability to combine and split digitized speech and data for transmission in the same channel, whereby data received at a port via the tone bus may be partitioned from the information field of the channel for use by a subscriber.