DAS architecture. For
   most purposes, DLA files can be thought of as having the following
   logical components:
<P>
 
<PRE>
   +----------------------------+
   |       file record          |
   +----------------------------+
   |       comment area         |
   |                            |
   |                            |
   +----------------------------+
   | DLA format version         |
   +----------------------------+
   | DLA forward and backward   |
   | pointers                   |
   +-------