var fileStreamObj = shell.serviceManager.basics.fileStream; var streamWriterObj = shell.serviceManager.basics.rawStreamWriter; fileStreamObj.openForWrite("c:\\temp\\test.txt", false, true); streamWriterObj.stream = fileStreamObj; streamWriterObj.writeUInt64(1024*1024*1024); streamWriterObj.writeUInt64(1024*1024*512); fileStreamObj.close();