The c8609 utility converts checkpoint files from Gaussian 86 through Gaussian 03 to Gaussian 09 format. It takes the name of the checkpoint file as its argument, and transforms it in place, so that the reformatted file has the same name as the original one. For example, the following command converts the checkpoint file taxol.chk in the Gaussian scratch directory to Gaussian 09 format:
$ c8609 $GAUSS_SCRDIR/taxol.chk
Last update: 23 April 2013