Abstract: A software-independent network which enables interconnection at video and keyboard level between one master computer and several slave computers, and is compatible with computers using either digital or analog video output. Hardware includes a master control box, and a plurality of switching circuits (one serving each slave computer) all of which are connected in cascade to the master control box by a single multicore cable; both master and slave units are interfaced with the relative computers via their standard VDU and keyboard connectors. Video images can be sent back and forth between instructor and students, the instructor can edit the screen of a student selected, or the student can edit the master screen, and a copy of the video image under scrutiny can be broadcast to all the students.