A detector of 40 pins connector, for 89C2051, 89C2041, 8951, 8952, pic, arduino, etc.,

The below was what I designed for a detector of the input port of 40 pins connector, it can be expanded to more pins to detect that when you need more I/O ports.




The below was what I designed for a detector of an output port of 40 pins connector, it can be expanded to more pins to detect that it just needs more I/O port.