There are three files of concern to TNORECOV.  One is the list of
observatories.  The default file is obscode.dat which resides in the
Buie IDL library directory.  You can override the default by using the
OBSFILE keyword, or, you can explictly load a copy of this file through
the File-->Get Obsfile menu item.

The main input file is the list of predicted positions and astrometric
errors.  A current copy of this file can be found at

ftp://ftp.lowell.edu/pub/buie/kbo/recov

Look for files of the form YYMMDD.dat where YYMMDD is the UT date.  These
files are generated each day for 0h UT on the date of the file.  This file
lists all TNO and Centaurs whether numbered or not.  This file contains
all the information used to fill up the display of this program.  If you need
to understand the file format, you'll have to look in the source code for
this program (look for tnorec_loadobs).

The output file which tracks the observations done thus far looks like this:

00CQ114 2001/03/13_07:47:49 [[noobs]]
00CQ110 2001/03/13_07:00:10 2001/03/13_09:00:30

Each line shows one object.  [[noobs]] is a special flag that indicates the
object was not yet measured a second time (or first).  The first column is
the object name, second column is the time of first observation, third column
is the time of second observation.  Note that each column is separated by
blanks and there are no blanks within a column (notice the underscore).
This is a simple text file and you can edit it (when tnorecov is NOT running)
if you wish.  Just be mindful of the format.