Ok!! more information. I have a bit stream of data with a known clock. (in otherwords I know that the data coming in was created with a 20 Mhz PIC osc / 4 = 5 Mhz) If I use a Manchester coding scheme I would read the data stream and add a clock to the stream, and send it down a pair of wires or coax. I would them strip the clock and use it to decode the data, and output the data on one pin at the other end. No I do not need the Ethernet protocol. Just the endcoding and decoding algorithems. Gordon Varney Note: I have started writing this algorithem and it does not apear difficult. If any one has Ideas or gotchus, please speak up!! MERRY CHRISTMAS ONE AND ALL