Windows NT 3.51 build 980

Windows NT 3.51 build 980.1 is an unleaked build of Windows NT 3.51 that was mentioned in the file  from the Windows NT 4.0 source code.

; Beginning with NT 3.51 (build 980 or so), the front of the export table
 * contains a signature and an export-table-version number. This allows
 * a DOS DLL to tell whether it has been loaded by an older application.