Post by thread:Logic on Parallel Port

Dear All, Now that I've managed to operate the parallel port, I'm now trying to read in logic from the outside world. To obtain the pure logic value, all zeros must be written to the data register before reading. The only way I can get a proper logic read is if I supply +5V directly to the port pins. If I tie the PIC directly to the pins, it begins to get very hot.......whoops. Does anybody have any ideas on how I can get the logic through using a PIC16C74? Thanks. J.W. ----------------------------------------------------------------- Johnnie Walker MSc Digital Systems Engineering Heriot-Watt University email: spam_OUTceejbcwTakeThisOuTcee.hw.ac.uk .....ceejbwKILLspam@spam@pp.hw.ac.uk ceejbwKILLspamtorduff.hw.ac.uk www: http://www.cee.hw.ac.uk/~ceejbcw tel: (0131) 343 2864 -----------------------------------------------------------------