Joe, I haven't used the dsPicc33 as yet and none of the books (like Creed=20 Huddleston) demo code uses RTS/CTS etc. Would it help if I sent you Microchips 'C' code setup examples from their=20 C30 library, to see if their figures agree with yours? Does your Pic have reconfigurable pins, if so have they been reconfigured=20 correctly? Colin -- cdb, colin@btech-online.co.uk on 30/06/2011 =20 Web presence: www.btech-online.co.uk =20 =20 Hosted by: www.justhost.com.au =20 =20 =20 =20 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .