***** File EPHINFO.TXT                                                        
                                                                              
     This information file is located in the EPHEM directory, which contains  
ephemeris information for comet P/Halley.  The ephemeris was generated by     
Donald K. Yeomans as described in the file EPHEM.TXT.  The actual data are    
provided in the table file EPHEM.TAB, which contains fully-perturbed, daily   
ephemerides for the interval 1981 November 26 -- 1989 June 23.  An            
interpolation program in the SOFTWARE directory of this disc allows accurate  
ephemeris data to be generated within a UT day using EPHEM.TAB as input.  The 
source code is called OBSNTERP.FOR, and MS-DOS- and VAX/VMS-based executables 
are PCNTERP.EXE and VAXNTERP.EXE, respectively.  A description of this        
software and how to use it can be found in the file OBSNTERP.TXT, located in  
both the DOCUMENT and SOFTWARE directories of this disc.