First off, let me state that I'm not a Windows Perl user. With that caveat, let me suggest a thought. I suspect that the buffering of an Entry widget is fairly small compared to that of a filesystem reader. It's a tribute to Perl that it doesn't crash, but you're filling/emptying the Entry widget's buffer from the Paste buffer many, many times. I'd suggest that you paste to Notepad, save it and then read the file in from Perl. I'll betcha that gives much faster response and also frees up your console. :D