Backward compatability of files

This option is not available - only 'bitmap' 'Metafile' etc

Yes. Get a copy of Intellicad. It will open almost all DWGs.

I read your post to indicate the drawing was modified with '05. If that is so, and you are in '05, the option is available.

Newer versions will open older file formats but older versions of software can not open the newer file format. You need to 'Save As' to the older file versions. AutoCAD and LT 2006/2005/2004 use a default of 2004.dwg format; AutoCAD and LT 2002/2000i/2000 use 2000.dwg format; AutoCAD 14 and LT98 uses R14.dwg format. To cover the range you need from 2005 Save As R12/LT2,dxf Or from 2005 Save As 2000.dwg and from 2002 Save As R14.dwg

Are you sure? I thought only verticals included the "Export to AutoCAD" function. Vanilla AutoCAD includes version 2002 in the regular SAVEAS dialog.

Say you have a 2004 drawing (AutoCAD 2004/5/6), and you save it back to R14. What should it do to TABLE, FIELD, and other entities that only exist in 4/5/6 versions?

I suppose if the drawing only contained entities supported in the savedown version - then it could be done. But the real issue here is if they allow you to savedown to R14 effortlessly - then there is no incentive for those R14 users to upgrade - and sales rule at software companies....

As I understand things the file format in AutoCad was consistant from 2000 to 2002, after that it changed and 2003 to 2006 is the same. I use 2006 and I am assuming that 2005 is similar. Try using "save as" in 2005 but change the format to 2000. If I am correct you should be able to open the newly saved file in 2002.

Hope this helps

Alan

You can down load from Autodesk a batch convertor that will convert 2004 back to R14. I've got it and it works pretty good. Converts R14/200/2004 format. It converted 600 ACAD2000 format drawings to 2004 in ten minutes! Failing this, save your work as a R12 dxf.

Hope this helps