I just installed the new driver from the Prolific web site on my Windows XP Home system and that works properly now too. I can talk to an EasyProg directly using the USB to serial converter. So this proves (as most of us thought anyway) that RTS/CTS handshaking is not required by the hardware nor a bug in Hyperterm, just a badly written and very badly tested driver. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist