Hi Lawrence,

Clay Sherrod's suggestion of replacing MPCORB with an NEA file,
such as NEATOD.DAT, will work. You can even edit MPCORB.DAT to
include only asteroids of interest, helpful if you've just got a
short list to be shown.

It may be easier, though, to make use of Guide's ability to
filter asteroids based on orbital characteristics, described at

http://www.projectpluto.com/update7.htm#asteroid_filtering

Basically, if you set up a filter such as

ASTFILTER=q<1.3

then only those asteroids with perihelion distances less than
1.3 AU will be shown. As described at the above link, you can
combine various constraints, so that Guide will (say) show only
the Trojan asteroids, or only Atens, or those asteroids above
a particular declination, and so on.

Replacing MPCORB does have two advantages. It can speed up
asteroid display a bit, because instead of plowing through
300,000 asteroids, Guide may have only a few thousand to deal
with. And at least a couple of times, I've set ASTFILTER and
forgotten about it. Then, a few days later, I'm wondering
why only certain selected asteroids are displaying. (Of course,
the same thing _could_ happen when replacing MPCORB.DAT.)

-- Bill