15.63.1  FIT 

SAVE FIT [FILE=file_name]
     [LOG[=ON|OFF]]
     [NAME="name of data"]
Saves  the  current  Topdrawer  fit  in  a  file.  If no file is specified
TDFIT.TFB is assumed.  The optional NAME  is  stored  in  the  file  as  a
comment.  The RESTORE command is used to get saved fit.