XP603.TXT - Differences in Version 6.03 for XP Developers	13Apr99
-----------------------------------------------------------------------

The 6.03 drawing file format has the following differences from
the earlier 5.21 file format:

1) The entity common stuff has added:

   EThick - a 1-byte pen thickness code
   EColor2 - entity 2nd color code
   EFlags2 - 2nd flags byte
   WPlane is now a 2-byte word rather than a single byte

   This makes every entity record 4 bytes larger.

2) The header record InfoBlock is now 256 bytes in size,
   rather than 128 bytes, to allow room for growth with
   out requiring another database change.

3) The FileID data has changed, showing minor version #s,
   the serial # of the saving fastcad, and a byte that
   indicates if the file is in compressed mode or normal
   mode.

4) Compressed mode files have the data after the FileID block
   compressed. You must use FastCAD to load or save compressed
   files. No documentation is available on the compression
   algorithm.

5) SHEET entities are now present and supported. These are
   like a group, except they can not nest and are always
   stored at the outer level. Entities in a sublist of
   a hidden sheet are never scanned.

The changes required to existing XP's for version 6.03 format
are:

1) All explicit entity record structures in your program
   must be modified to include the new CStuff. This includes
   custom XPs and any existing entity structures that you may
   have declared as initial storeage constants, etc.

2) If you use a custom entity "header record", you should
   create it with SVC DLApndM, which always appends to
   the main drawing list, rather than the current sheet.
   This is to insure it will be found - if it were appended
   to a sheet, that sheet might be hidden, and it would
   not show up in a scan.

   You find such a record by scanning the main drawing list.
   If you use DL_Std+DLSHEETS+DL_NOWDC, the scan will go much
   faster.

3) Header record changes should not be a concern - rebuild
   with the current structures should be all that is necessary -
   Headers with the smaller size are automatically converted.

4) Compressed files are only of concern for those who read
   FastCAD files with non-XP programs - they will be unable
   to do so for compressed files; They will still be able to
   read normal files.

5) If you have any conversion questions, contact me at:

   mriddle@fastcad.com
