A: Serial Connection. Connecting up to 64 computers serially. Used in a computer classroom with less than 64 computers.

B: Star Connection. Five integrated serial connections integrated in a Junction Box. Each serial connection connects up to 64 computers. Used in a large computer classroom.

C: In a system of NC 400, multiple external equipment can be connected to the instructor's workstation to form an integral system. Possible equipment includes but it is not limited to: DVD player, audio recorder, video recorder, projector, TV, etc.