diff --git a/tools/src_to7bits.py b/tools/src_to7bits.py
new file mode 100755
index 00000000..e979227b
--- /dev/null
+++ b/tools/src_to7bits.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+# vim:expandtab:ts=2 sw=2:
+#
+# Tool to convert 8bits C sources (with Latin1 chars in litterals)
+# to 7bits sources using escape sequences in litterals
+#
+# Do not convert 8bits chars which are in comments !
+#
+# Copyright 2018 Thomas Bernard
+#
+import sys
+import os
+import re
+
+conv_format = '\\%03o'  # octal
+#conv_format = '\\x%02x' # hex
+
+# for C++ style comments //
+commentre = re.compile('(.*)(\/\/.*)', re.MULTILINE | re.DOTALL)
+
+def escape_8bit_chars(char):
+  if ord(char) >= 0x7f:
+    return (conv_format % ord(char))
+  else:
+    return char
+
+# return True if there was any translation
+# and a filename+'.out' file was written
+def to_7bit(filename):
+  with open(filename, "r") as f:
+    output = ''
+    in_comment = False  # C style comments /*  */
+    for line in f.readlines():
+      comment_start = 0
+      comment_end = -1
+      if not in_comment:
+        comment_start = line.find('/*')
+        if comment_start >= 0:
+          in_comment = True
+      if in_comment:
+        comment_end = line.find('*/', comment_start)
+        if comment_end >= 0:
+          in_comment = False
+      # skip all lines with C style comments
+      if in_comment:
+        (line, comment) = ('', line)
+      elif comment_start < comment_end:
+        # Note : the characters after the end of the comment are not translated
+        (line, comment) = (line[0:comment_start], line[comment_start:])
+      else:
+        m = commentre.match(line)
+        if m is not None:
+          (line, comment) = m.group(1,2)
+        else:
+          comment = ''
+      conv = ''.join(map(escape_8bit_chars, list(line)))
+      output = output + conv + comment
+    if f.tell() < len(output):
+      with open(filename + '.out', "w") as fout:
+        fout.write(output)
+      return True
+    else:
+      return False
+
+# program entry point
+if len(sys.argv) <= 1:
+  print ('Usage: %s <file.c> ... <file.c>' % sys.argv[0])
+  print 'Convert C sources files to 7bit ASCII'
+else:
+  for i in range(1,len(sys.argv)):
+    if to_7bit(sys.argv[i]):
+      print ("File %s translated" % sys.argv[i])
+      os.rename(sys.argv[i], sys.argv[i]+'.orig')
+      os.rename(sys.argv[i]+'.out', sys.argv[i])