MM2 size limits, request for information

I've recently examined the Fortran source code for QCPE's MM2.
 The version I've examined can only handle 500 atoms.  The constant
 500 (and various other integer constants of mysterious purpose)
 are scattered throughout the code in array declarations, DO loop
 limits, statement labels, substrings of floating point numbers,
 and the like.
 Has anyone modified the QCPE code to parameterize the number of
 atoms it can handle?  We're not sure how large a structure we'll
 want to handle, but more than 500 atoms is certain.
 Send any replys or information to:  merkle-: at