CD-ROM access routines for VAX/VMS                      29 November 1989
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The programs in this directory were developed by:

     United States Geological Survey
     Branch of Astro Geology
     2255 N. Gemini Drive
     Flagstaff, AZ  86001

for the purpose of reading the CD-ROMs produced in the ISO 9660 format 
standard (or in the "High Sierra" standard) on a VAX/VMS computer
system.  Permission has been obtained from the U.S.G.S. to place
these programs on the VAX SIG tape.  The programs are in the public
domain, and are provided for use with the following disclaimer:

	"Although these programs have been used by the United
	States Geological Survey no warranty expressed or
	implied is made by the USGS as to the accuracy and
	functioning of the programs and related program
	materials, and no responsibility is assumed by the
	USGS in connection therewith."

The programs were produced to read the Voyager CD-ROMs to be read on VAXes.


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The programs allow a file on an ISO 9660 format CD-ROM to be opened, and
512 byte blocks of data read from the file relative to the beginning of
the file.

The original files from the U.S.G.S., as downloaded from the SPAN network,
are   CDVMS2.TXT;2   and   CDVMS3.TXT;1.

All other files were extracted from these .TXT files, with the exception
of the B2B.MAR program which was not in the original files and was sent
in hardcopy by U.S.G.S. and rekeyed.  All programs work with either
ISO 9660 or "High Sierra" format CD-ROMs.  Main programs provided are:

     CDDIR     Do a directory listing of a CD-ROM
     CDCOPY    Copy a file from a CD-ROM to another device
     CDTYPE    Type the contents of a file on a CD-ROM


The original version of CDDIR (CDDIR.ORIGINAL) was modified at ICDD to
default to a 3 character file extension since the LENOSP routine used
in CDDIR was missing.  The original version of CDOPEN (CDOPEN.ORIGINAL)
was modified at ICDD to correctly find and report the contents of the
extended attribute record (XAR).  The following subroutines are provided:

     CDOPEN    Find and open a CD-ROM file, returning the offset of
               the start of the file
     CDREAD    Read 512 byte block records relative to the beginning
               of the file
     CDCLOSE   Close a CD-ROM file
     CDSTAND   Determine if the CD-ROM is ISO 9660 or "High Sierra"
     CDATT     Obtain extended attribute record (XAR); CDATT is an
               ENTRY point within CDOPEN
     B2B       Move bytes


All executables were produced on a VAX/VMS V5.2 system.


* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

These routines have been made available to the VAX SIG tape by:

     Mark A. Holomany
     JCPDS-International Centre for Diffraction Data
     1601 Park Lane
     Swarthmore, PA  19081  U.S.A.
     (215) 328-9403

The disclaimer that appears at the beginning of this file applies also to
Mark A. Holomany and the JCPDS-International Centre for Diffraction Data
(also known as ICDD).

These routines were described in the session "CDROM Use on a VAX/VMS System"
(VA076) given at the Fall 1989 DECUS Symposium in Anaheim by Mark A. Holomany.
The session was taped.

Feel free to contact me at the above number should you have any comments on
these programs, or if you have any questions on CD-ROMs in general.

[End of AAAREADME.TXT]