On 2/9/07, Vitaliy wrote: > > > Why are you using handshaking lines? Handshaking is a good way to start the protocol from a know point. If available for free such as in a serial cable to a PC it eases development since you have a way, from the PC, to tell the PIC to start over (or vice-versa). Sure everything that's done with handshaking can also be done without, but if it's more difficult and the lines are already there... For example if the PIC resets for whatever reason the handshake is still there telling it to send data to the PC after it initializes, and no time is lost. Try doing that without handshake, how do you save state between resets? If however you let the PIC send data regardless you'll have to switch it off manually before starting the PC program as Windows won't let you open the port when it's active receiving data (even if no other program is using it). Why are you using interrupts for transmit? Why not? It's better than polling. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist