--- dmupdate.py.orig	2017-07-04 06:21:14.850810096 -0400
+++ dmupdate.py	2017-07-04 06:21:14.854143781 -0400
@@ -257,12 +257,19 @@ while args and args[0].startswith('-'):
     del args[0]
 
 if e is None:
     e = b
 
-host = args[0]
-filename = args[1]
+try:
+    host = args[0]
+    filename = args[1]
+except:
+    print "Usage:  dmupdate.py [-rqsg] [-b <addr] [-e <addr>] <hostname> <filename>"
+    print "filename as .cmtl is preferred. .bin (ARM7) and .nxbin (Cortex-M) also work"
+    print "For more help:"
+    print "less +96 -S /usr/share/nslink/README.txt"
+    sys.exit(1)
 
 if not zipfile.is_zipfile(filename):
     binfile = open(filename,"rb")
 else:
     archsuffix = {3:".bin", 5:".nxbin"}