Invoking this option leads to output of the current version of the node file in NODE format. Node editing can be resumed after an interim save, which should be used at regular intervals during a long editing session to avoid losing one's work in the event of power failure or other interruption. Alternate interim saves are written to files named interim1.dat and interim2.dat ; the name of the last interim save file output can be checked by using {TOP.INFO}FILES. The interim save files are erased automatically if a normal SAVEAS is successfully carried out at the end of the session.