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Reading Your CD-ROM

With the start of AO5, the processing team has replaced most tape distributions with CD-ROMs. You can now analyze your data directly from the CD, without first having to load the data from tape to magnetic disk. CDs are also more reliable than tapes, and they contain a convenient HTML interface to your data and various useful documents.

Reading Your Disc

This can be as easy as putting the disc in the drive with the gold side up and green side down. On some systems you may need to ask your system administrator to mount the disc as a file system before you can access it.

The discs are written in the standard ISO 9660 format with the Rock Ridge Extensions which permit UNIX-style file names. If the names of the files on your disc are in all caps and are truncated to 8.3 characters (e.g. HOME.HTM instead of home.html), then you need to consult your system administrator about mounting the disc in a way which is compatible with the Rock Ridge Extensions. Most systems, including SunOS, Solaris, and DEC UNIX can do this.

If you have one of the rare systems which do not yet support the Rock Ridge Extensions, all is not lost. You can still access your data, but the file names will be changed. All FITS files hold their original file name in the "FNAME" keyword. However, the HTML links on the disc will not work, since they refer to the original file names. If you prefer, you can contact the processing team through ascahelp@athena.gsfc.nasa.gov, and we will provide your data by some other means.

What is on Your Disc

The top level directory on your disc contains one file (home.html) and two directories (one named doc, and the other named after the sequence number).

The home.html file is the top level "home page" for the HTML documentation on your disc. You can read it with your World Wide Web browser, usually by selecting the "open file" or "open local" option or by including the file name on the command line at startup. From the home page you can view all of the hardcopy which usually accompanies a distribution, all of the images and plots produced in processing, and extensive documentation of ASCA and your data.

The doc directory contains the documentation referred to by the home page. It is probably easiest to navigate the files and subdirectories below doc with your Web browser. They are all accessible by hyperlinks from home.html.

The directory named after your sequence number contains all of your data products. For more on these files see the ASCA Distribution Files chapter of this guide.


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Next: FTP Previous: Reading/Obtaining