Re: Software Helper

[hjohnson@pluto.njcc.com (Herbert R Johnson)]

On Thu, 24 Feb 2000 19:05:52 -0600, Tom Droege <droege@wwa.com> wrote:
*>I just had a message from someone that was trying to look at one of the
*>images I sent out on CD ROM and without success.  Possibly one of you could
*>take on the task of helping those new to this game get some viewer programs
*>up and running.  I looked at the tass software page and told him to try
*>FitsView.  As always, help by someone that has actually done it would be
*>best.  Please, someone who is not already working on something.  Just send
*>a message to the list saying "I will help you get some software working"
*>
*>Tom Droege

One issue to be aware of is that some of Tom's images have a FITS header which
does not always include the keyword statement "BZERO = 32768". I found
that Astrometrica (a DOS shareware program which I strongly recommend)
required this keyword and value in order to set a reasonable display
level. Otherwise it assumed the zero point for the image data was
ZERO: the image did not display.

I simply moved the image from CD-ROM to hard drive and edited the
header to insert the above keyword, overwriting another similar keyword.
I used a special editor that simply changed the contents of the file
ON DISK, rather than attempt to edit a mixed text and binary file with
a text editor. Such editors are often called "binary editors", "hex
editors" or "disk sector editors". They are used to make changes in binary
files that would simply be corrupted by conventional editors, by allowing
one to edit the file "in place" on disk. They are great for fixing
text messages in executable programs without recompiling (if the programs
are not in compresssed formats).

The program I used in Windows 95 is a shareware program called HexEdit. A
search of shareware archives for your favorite operating system, using
the keywords above, will find appropriate programs.

Tom, you are welcome to include the above info (or ask for more info)
with any future distributions of your data.
Herbert R. Johnson              http://pluto.njcc.com/~hjohnson
hjohnson@pluto.njcc.com         voice 609-771-1503, New Jersey USA
             amateur astronomer and astro-tour guide
           S-100 computer parts, manuals as "Dr. S-100"
    reseller of 68K Macs & accessories for your computing pleasure