This may be old news to some Guide users, but
Guide is kind of fussy about the name that a
TDF file and its associated .dat file is given.

For example, I found that Guide would not accept
a .tdf filname with more than 8 characters. More
than 8 and Guide crashes.

The .dat filename can be longer than 8 characters but
if there are spaces in the filename, Guide may or
may not accept them. For example, I created .tdf
and .dat files for some of the photometry from the
ASAS (All Sky Automated Survey). These are V
magnitudes measured with an array of wide-field
CCD cameras. The fields were located around some
bright variable stars. The name of one .dat file:

RS Oph - ASAS V seq.dat

worked fine. However,

T CrB - ASAS V seq.dat

did not. When i tried to use the second file, an
invalid page fault occurred in GUIDE.EXE.

The unfortunate part of all this is that I wasted
over two hours trying to examine the format of both
the .tdf and .dat files thinking that I made a typo
or some other error in the contents of each file,
when in fact it was the file name that was the
source of the problem. I changed the second .dat
file above to:

T_CrB - ASAS V seq.dat

and now it works.

Bill, perhaps you could find a more graceful way
to have Guide handle situations like this? Maybe
an error box that says "bad file name" or something
similar. Anything but a crash!

Thanks,

Bob Modic