Charles Craft mindspring.com> writes: =20 > > Several tools come to mind: sed - for command line editing;=20 > Those won't do him any good unless he converts it to ASCII. > It's an ASCII string embedded in a binary file that he wants to change. That's exactly what sed will do. OP specified that he needs to change ASCI= I string. Might need to maintain the string length, but that's about it. =20 command line is:=20 sed s/Search String/Subst. String/ filename > newFilename I just verified it o a bin file generated by gcc (actually a Hello World in= QT4). Sergey Dryga http://beaglerobotics.com --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .