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---- 8.3.3 display_adjust ----
Controls how are generate the video modes. Correct use of this
option removes the need of any software stretching improving a
lot the game image.

For an introduction on how the program operates on video mode,
you can see the install.txt' file.

display_adjust none | x | clock | xclock | generate_exact
| generate_y | generate_clock | generate_clocky
| generate_yclock

Options:
   none - No automatic video mode creation. Use only the
       available modelines (default).
   x - Adjusts the available modeline horizontal resolution
       to match the game image's size. The stretched modeline
       keeps all the clock attributes of the original
       modeline. Also all other modeline attributes,
       like doublescan and interlace, are maintained.
   clock - Adjusts the available modeline's vertical clock
       to match the game's frame rate.
   xclock - Adjusts the available modeline's horizontal resolution
       and the vertical clock.
   generate_exact - Creates automatically some new modelines using
       the format specified on the device_video_format'
       option. The generated modelines will be named generate-*'.
       Check the advdef.txt' file for the description of
       the device_video_format' option or simply use the
       advcfg' utility to set it up correctly.
       If the device_video_format' option isn't
       specified a default value for your monitor clock
       limits is guessed.
   generate_y - Like generate_exact, and it allows generating
       modes with a wrong vertical size if a perfect mode is not
       possible.
   generate_clock - Like generate_exact, and it allows generating
       modes with a vertical clock different than the game
       original clock if a perfect mode is not possible.
   generate_yclock - Like generate_exact, and it allows
       generating modes with a wrong vertical clock and/or size
       if a perfect mode is not possible. Modes with a correct size
       are favorite over mode than a correct clock.
   generate_clocky - Like generate_exact, and it allows
       generating modes with a wrong vertical clock and/or size
       if a perfect mode is not possible. Modes with a correct clock
       are favorite over mode with a correct size.

The generate' options are able to create at runtime all the
required modelines. You don't need to create a list of modelines
manually.

The not generate' options use only the modelines defined with
the device_video_modeline' option in the configuration file.
You can add them manually or using the advv' utility.
Check the advdev.txt' file for more details on the
device_video_modeline' option.

Of all the generate' options, the generate_yclock' is the
suggested and the most powerful. The advcfg' utility always
sets the generate_yclock' option in your configuration file.

Of all the not generate' options, the xclock' is the
suggested and the most powerful.

If you can't get good result with the generate' options you
should create a list of modelines and try with the xclock' value.
You don't need to duplicate the same modeline with different
horizontal resolutions and/or the clocks, because the xclock'
value allows the program to adjust them.
Instead, you should create a wide set of different vertical
resolutions on which the video mode can be chosen.
A good choice is to create all the resolutions with a step of
16 rows.