| 摘要 |
PURPOSE:To readily detect the normal connection of an arithmetic unit and a printer with a simple and inexpensive structure in an electronic device with the printer by constructing to detect it with a signal line. CONSTITUTION:A signal line D9 which is connected to a switch SW provided at a calculator DT side is branched to two segments, one of which is connected to an input line of an AND gate A, the other of which is connected to the terminal T1 of a connector C and to the other input of the AND gate A through terminals T1, T3 of a printer PU side connector C and the terminal T4 of a connector C of the calculator DT side. In this manner, when the switch SW is closed at the time of necessitating recording, the output AO of the gate A is inputted to a central processing unit CPU only when the printer PU is normally connected, thereby driving a motor M of the printer PU. A signal is fed to a display unit DSP, and a mark M which recognizes the normal connection is displayed. |
