SRB2/doc/Doublescan.txt

   ================================================================
   How to add Low-res modes to your XF86Config under Linux MANUALLY
   ================================================================

   I TAKE NO RESPONSIBILITY FOR ANY DAMAGE DONE TO YOUR EQUIPMENT!!!

   This document explains how to add low-res modes like 320x200 to your
   X-Server configuration, because some new setup tools for the X-Server
   do not support this. ONLY RECOMMENDED FOR USERS WHO KNOW WHAT THEY DO!

   I do not take any responsibility for damage done to your monitor, your
   videocard, your harddisk, your cat, your dog or anything else!!!
   IMPORTANT IS, THAT YOUR "HorizSync" AND "VertRefresh" VALUES REALLY
   MATCH YOUR MONITOR! OTHERWISE YOUR MONITOR CAN BLOW UP!!!

   OK, if you have read up to here, you either know what you do or really
   die-hard want those low-res modes. Here is what to do:
   Look up your XF86Config. Is is either in /etc or in /etc/X11. Here is
   what you have to add to the definition of your modeslines:

# Low-res Doublescan modes
# If your chipset does not support doublescan, you get a 'squashed'
# resolution like 320x400.

# 320x200 @ 70 Hz, 31.5 kHz hsync, 8:5 aspect ratio
Modeline "320x200"     12.588 320  336  384  400   200  204  205  225 Doublescan
# 320x240 @ 60 Hz, 31.5 kHz hsync, 4:3 aspect ratio
Modeline "320x240"     12.588 320  336  384  400   240  245  246  262 Doublescan
# 320x240 @ 72 Hz, 36.5 kHz hsync
Modeline "320x240"     15.750 320  336  384  400   240  244  246  262 Doublescan
# 400x300 @ 56 Hz, 35.2 kHz hsync, 4:3 aspect ratio
ModeLine "400x300"     18     400  416  448  512   300  301  302  312 Doublescan
# 400x300 @ 60 Hz, 37.8 kHz hsync
Modeline "400x300"     20     400  416  480  528   300  301  303  314 Doublescan
# 400x300 @ 72 Hz, 48.0 kHz hsync
Modeline "400x300"     25     400  424  488  520   300  319  322  333 Doublescan

   If your video card only supports a specific set of discrete dotclocks
   (RAMDAC) you may have to replace the dotclocks given here by one of the
   specified (e.g in the first modeline the dotclock is 12.588 MHz). I believe
   that nowadays all cards and monitors should work with these settings, but
   if you have outdated hardware you better check the frequencies yourself. If
   there is any uncertainty, please check the "XFree86 Video Timings HOWTO".


   Then have a look at the section "Screen" with the appropriate driver
   (usually either "svga" or "accel"). Under Subsection "Display" there
   are modes for the given color depth. Add the desired modes. As an
   example I give you my screens definition here with low-res modes in
   16 bit color depth:

Section "Screen"
    Driver      "accel"
    Device      "3D Charger"
    Monitor     "Iiyama Pro 450"
    DefaultColorDepth 16

    Subsection "Display"
        Depth       8
        Modes       "1280x1024" "1024x768" "800x600" "640x480"
        ViewPort    0 0
        Virtual     1280 1024
    EndSubsection
    Subsection "Display"
        Depth       16
        Modes       "1152x864" "1024x768" "800x600" "640x480" "400x300" "320x200" <- THIS IS ACTUALLY WHAT YOU WANT!!!
        ViewPort    0 0                                       ^^^^^^^^^^^^^^^^^^^
        Virtual     1152 864
    EndSubsection
    Subsection "Display"
        Depth       24
        Modes       "800x600" "640x480"
        ViewPort    0 0
        Virtual     800 600
    EndSubsection
    Subsection "Display"
        Depth       32
        Modes       "800x600" "640x480"
        ViewPort    0 0
        Virtual     800 600
    EndSubsection
EndSection

   Once again: important is, that you edit the correct Screen section.
   If you use the SVGA Server and edit the ACCEL Server, you might
   wonder where your new modes have gone.

   If everything went fine and you want to say thank you, just write
   to "metzgermeister@users.sourceforge.net". If your monitor blew
   up and you want to kill me, find me playing Legacy or Q3A on the net
   and frag me (with your second monitor, hehe).

   - metzgermeister