    This section contains a utility program for the POV-Ray IBM-PC protected
 mode executable compiled with Intel's 'Code Builder Kit' 32-bit 'C' compi-
 ler.  It is not of any use for exectuables compiled with any other compiler.
 It's purpose is to expand (or reduce) the amount of virtual memory available
 to POV-Ray during it's operation.

    NOTE: If you get a message about running out of memory (allocation fai-
 lure...., memory exhausted......, insufficient memory....  etc...), you
 should use this utility.  It's unneeded until your image models become com-
 plex enough to require more than the 3072K of virtual memory that POV-Ray
 uses as it's distribution default.

    The 'region size' consists of the physical RAM *PLUS* the amount of disk
 space allocated to a swapfile for POV-Ray.  The unmodified POV-Ray will ren-
 der approximately a 15,000 triangle file.  (Supports 3072K of memory.  In a
 machine with less than 4 megs of RAM the VMM may be used to raise it to that
 amount.  In a machine with *more* than 3072K of RAM it will go ahead and use
 it, if available, when run 'stand alone'.  I.E.  when not running under a
 DPMI host such as Windows, OS/2 2.x or QEMM w/ QDPMI installed.)

    To expand the amount of virtual memory available, more Hard Disk space
 must be allocated to POV-Ray.  POVMOD will list the amount of physical RAM
 available in the machine PLUS the free space on the hard disk.  Any or all
 if this can be allocated for POV-Ray's use during a trace.

    NOTE: These amounts may not reflect the actual amount installed in the
 machine when running under a DPMI Host.  They are the amounts reported by
 the host and must be configured in the setup of the host.  For instance the
 amount of XMS and DPMI memory is set under the DOS SETTINGS for an OS/2 2.x
 DOS session.


 Use of POVMOD:

    Place POVMOD in the same directory as POVRAY.EXE.  From the command line
 type:
       POVMOD POVRAY.EXE  <enter>

    The program will run and present a list of the current parameters that
 POV-Ray operates under.  The number in the upper right corner of the table
 (the one labeled 'Region Size:') is the amount of memory (both virtual and
 physical combined AT THAT TIME.) that POV-Ray can use.

    Press (M)odify to change the parameters.

    Press (E)nter to alter the region size.  You can then manually enter the
 amount of memory you would like to have available for the program to use.
 Generally a value of 6M to 10M will cover all but the most complex images.

    The (A)ccept key will configure the region size for the largest possible
 swap file size.

    NOTE: Accept is not the best choice in most cases.  If there is a large
 amount of free space on your HD it could result in a very large swap file.

    The (C)reate option will create a -permanent- swap file.

    REMEMBER: You need enough free disk space to write out your image file as
 it is created though!!!

    The POV-Ray executable file will then be modified to reflect your choi-
 ces.  Since much of this 'memory' is usually a swap file on your hard disk
 you will get much better performance with a recently defragmented disk.  The
 program will NOT allow you to allocate a larger region size than can be
 created AT THAT TIME.  For example: If you have 6 Megs of combined RAM/Hard
 Disk space available you cannot make the region size any larger than that.
 Also if the region size is set to a particular amount and your hard disk is
 later filled to the point that the free disk space is not large enough for
 the required swap file to be created, the program will NOT run.  It will
 error with an insufficient memory message.  You will need to modify the re-
 gion size to accommodate the smaller amount of disk space available.

    An environment variable is used to 'point' to the location of the swap
 file.  The DEFAULT swap file is C:\XMSWAP.TMP.  To set it to another loca-
 tion the following must be added to your AUTOEXEC.BAT file:
       SET SWAP=d:\[subdir]\XMSWAP.TMP
 where d: is the drive and [subdir] is the subdirectory you wish to use for
 the swap file.  You will need to reboot the machine for this parameter to
 take effect.


OS/2 2.x Note:

    When running POV-Ray under OS/2 2.x you need to set the DPMI_MEMORY_LIMIT
 value under the DOS SETTINGS for the session to a value GREATER than or
 EQUAL to the Region Size you set in the POVRAY executable with this program.
