> If you are sending data DIRECTLY to the PC without using the MAX chip, you > need to invert your data. This is the only case that I'm aware of that you > need to do this. I believe the reason for this is that the PC reads (-) > values as "1" and (+) values as "0". PCs conform to the RS-232 standard, which is inverted from the 0 to 5 volt levels used by the PIC UART. You need the same level conversion and inversion whether you are connecting to a PC or any other "normal" RS-232 device. The main difference between devices out there is that some will be "terminal" equipment versus "computing" equipment and have RX/TX (and other pairs) flipped. ***************************************************************** Olin Lathrop, embedded systems consultant in Devens Massachusetts (978) 772-3129, olin@embedinc.com, http://www.embedinc.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics