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## 3. Let's go

Let's suppose that you have your oh-so-tweaked XFree86 mode and you want to evaluate Xinside in the same conditions: follow the steps described below and you should be able to do it; we will use my default video mode as a real-life example and I will explain what you will have to do to convert it.

An Xfree86 entry looks like this:

> `

>     Modeline "blahblah" DOTCLK  A B C D  a b c d

> `

Every one of the A-D and a-d numbers has a meaning: if you want you can search for it in the 'The Hitchhiker's Guide to X386/XFree86 Video Timing' ( /usr/lib/X11/doc/VideoModes.doc ) but you don't need to know the theory behind all this to perform a succesful conversion...

My modeline in /usr/lib/X11/XF86Config is:

> `

>     Modeline "1168x876" 105  1168 1256 1544 1640  876 877 891 900
>                          |     |    |    |    |    |   |   |   |
>                       DOT_CLK  A    B    C    D    a   b   c   d

> `

In Xinside, you have to add an entry in the Xtimings file, which should be located in etc/ ( from now on we suppose you are in the top Xaccel directory that should be something like /usr/X11/lib/X11/AcceleratedX )

> `

>     !    Somewhere in the file, put here the name you want

>     [PREADJUSTED_TIMING]
>         PreadjustedTimingName = "1168x876 @ 72Hz";

>     !
>     !    These four are obvious
>     !
>         HorPixel          = 1168;         // pixels
>         VerPixel          = 876;          // lines
>         PixelWidthRatio   = 4;
>         PixelHeightRatio  = 3;

>     !
>     !   hsync: DOT_CLK / D * 1000 [KHz]
>     !
>     !   hsync = 105 / 1640 * 1000 = 64.024 KHz
>     !
>     !   vsync: ( 1 / (( D / DOT_CLK ) * d) ) * 1,000,000 [Hz]
>     !
>     !   vsync: ( 1 / (( 1640 / 105 ) * 900) ) * 1,000,000
>     !           ( 1 / 14057.1428571 ) * 1,000,000 = 71.138 Hz
>     !

>         HorFrequency      = 64.180;        // kHz
>         VerFrequency      = 71.138;        // Hz

>     !   Obvious

>         ScanType          = NONINTERLACED;

>     !
>     !   Put here the +/-hsync +/-vsync XFree86 options
>     !
>         HorSyncPolarity   = POSITIVE;
>         VerSyncPolarity   = POSITIVE;

>     !   Shouldn't change

>         CharacterWidth    = 8;             // pixels

>     !   DOT_CLK here

>         PixelClock        = 105.000;       // MHz
>     !
>     !
>     !   horizontal timings section: [usec]
>     !
>         HorTotalTime  = D / DOT_CLK                  = 15.619;
>         HorAddrTime   = A / DOT_CLK                  = 11.124;
>         HorBlankStart = A / DOT_CLK                  = 11.124;
>         HorBlankTime  = HorTotalTime - HorBlankStart =  4.495;
>         HorSyncStart  = B / DOT_CLK                  = 11.962;
>         HorSyncTime   = C / DOT_CLK - HorSyncStart   =  2.743;

>      !
>      !  vertical timings section:    [msec]
>      !

>         VerTotalTime  = ( HorTotalTime * d ) / 1000  = 14.057;
>         VerAddrTime   = ( HorTotalTime * a ) / 1000  = 13.682;
>         VerBlankStart = ( HorTotalTime * a ) / 1000  = 13.682;
>         VerBlankTime  = VerTotalTime - VerBlankStart =  0.375;
>         VerSyncStart  = ( HorTotalTime * b ) / 1000  = 13.698;
>         VerSyncTime   = ( HorTotalTime * ( c - b ) ) / 1000
>                                                      = 0.219

>      ! Finished !

> `

Now you have to put this newly created mode in the files shown below in the appropriate place.

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