Invoking this option leads to output of the current version of the grid in NEIGH format. The resulting file is less compact than the NEIGH file obtained with the usual EXIT procedure (see below), as there are extra columns in which the neighbours are all zero, but is a useful facility and 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 via the {TOP.INFO}FILES option. The interim save files are erased automatically if a normal EXIT is successfully carried out at the end of the session.