I've been battling this for a few days now and I stumbled upon this post that is very similar to what I'm trying to accomplish. It uses the exact output also, the xdld command to put the device in download mode. I don't need this process automated however, and I don't want it to do it on startup. I just cant seem to get the code right for opening com1 and sending it the right xdld command. I'm using visual basic 2003 and I know it should be just a few lines, but I'm a novice in this area. Any help in this area is much appreciated, again... all I need to do is open com1, utilize the XDLD command and then I have a separate batch file that will download the file once it is in that mode. Thanks for any help!