dt = Open( "$sample_data/big class.jmp" );
dt << save( "$temp/deleteme.csv" ); // create a temporary CSV
csvtxt = Load Text File( "$temp/deleteme.csv" ); // and load it as text
ziparchive = Open( "$temp/deleteme.zip", "zip" ); // open a new or existing ZIP
Show( ziparchive << dir ); // old members
actualname = ziparchive << Write( "bigclass.csv", csvtxt ); // add new member
Show( ziparchive << dir ); // the new name may change if conflict
restore = ziparchive << read( actualname, Format( blob ) ); // read the new member
path = Save Text File( "$temp/deleteme2.csv", restore ); // put back on disk
Open( path ); // finish the round-trip by opening
Craige