This script runs the ASMAPPEND tool on a collection of XTE ASM master files and their respective incoming files. The user inputs the names of the directories containing the master files and the incoming files. The user may also specify the types of files to append (e.g. .lc or .col). The master files are updated in place in the master subdirectory. Note that the script outputs a number of informational messages used in the process of development. KNOWN BUGS: A) The name of the subdirectories must not contain an underscore ("_"), as this will confuse the source name search routine. B) The script does not correctly update the master list if the last entry in the incoming list is not in the master. We recommend that the user put such entries into the master subdirectory by hand.