TERMINAL, DATA PROCESSOR, SWITCHING UNIT, INTERFACE, AND KEYBOARD THE LATTER THREE CONNECTED TO THE FORMER TWO

摘要

A terminal comprising a terminal body (2) provided with a key-input circuit (21) and a CPU (22), and a switching unit (3) detachably connected to the terminal body (2) via connectors (4, 5). The number n of switching signal input terminals (41-4n) provided in the key-input circuit (21) is equal to or greater than the number N of switches (11-1N) provided in the switching unit (3) (n >/= N). A generator (6) provided in the switching unit (3) generates a signal specifying the number N when the number N is set. The specifying signal is fed to the key-input circuit (21). The CPU (22) of the terminal body (2) receives switching signals only from the input terminals whose number is equal to the number N. Thereby, plural kinds of switching units having different numbers of switches can be used, connecting them to one terminal body.