INFORMATION PROCESSOR

PURPOSE:To prevent the occurrence of a malfunction caused by the erroneous operation of the operator of a handy terminal at the time of down-loading a program code. CONSTITUTION:A handy terminal 1 is connected to an optical interface box 5 through an optical interface means 3 in an information exchangeable state. When a power switch 12 is turned off, the box 5 sets a power switch 12 to a turned-on state by means of a control circuit 13. Thereafter, the program code of the application program, etc., of the terminal 1 is sent from an optical interface port 8 to another optical interface port 7. The terminal 1 stores the down-loaded program code in a RAM 17 and makes operations based on the stored content. The down-loading can be easily and surely performed by mounting the terminal 1 on the box 5 in a state where the switch 12 is not turned on.