> The baud rate accuracy requirement increases with baud rate Error percentage is constant, whatever the speed. The only way to do serial with any confidence when the clock is liable to drift would be to use bit-banging, timing based on a bit length of the external transmitter. Not as convenient as the PIC's serial module but it can be done fairly easily Joe --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .