| 摘要 |
PURPOSE:To make the processing for electrically connecting an input terminal of an empty slot and an output terminal unnecessary by adding an insertion discrimination circuit for discriminating whether or not an IOC is inserted into a card frame. CONSTITUTION:When an I/O controller (IOC) is inserted into a connector 18 on a card frame 2, a contact point of a microswitch 16 is turned on. In terms of two-input NAND gate 14, its gate signal 17 goes to a low level, while its output goes to a high impedance state. Then a priority line 6 at the side of the next slot is transmitted to the next slot as it is. If the IOC3 is not inserted and goes to an empty slot 4, a contact point of the microswitch 16 is not introduced and turned off. Then the gate signal 17 of the two-input NAND gate 14 goes to a high level, and an input level from a priority line 5 at the side of a CPU1 of the two-input NAND gate 14 is transmitted as an output level to the next slot as it is. |
