In the excerpts shown below the -> sign tells you what was modified: do NOT include it in your files!
Monitor entry ( mine is monitors/mfreq/mfreq64.vda)
[ESTABLISHED_TIMINGS]
"640x480 @ 60Hz",
"640x480 @ 72Hz",
"640x480 @ 75Hz",
"800x600 @ 56Hz",
"800x600 @ 60Hz",
"800x600 @ 72Hz",
"800x600 @ 75Hz",
"1024x768 Interlaced",
"1024x768 @ 60Hz",
"1024x768 @ 70Hz",
"1024x768 @ 75Hz",
"1152x900 Interlaced",
"1152x900 @ 60Hz",
"1152x900 @ 67Hz",
-> "1168x876 @ 72Hz",
"1280x1024 Interlaced",
"1280x1024 @ 60Hz",
"1600x1200 Interlaced";
Board info file ( mine is boards/s3/764-2.xqa , I wonder why they have nearly all the Hercules boards but not MINE: Terminator 64/Dram )
[VISUAL]
BitsPerPixel = 8;
MemoryModel = Packed;
ColorModel = Indexed;
BitsRGB = 6;
NumberOfColors = 256;
[RESOLUTIONS]
640x480,
800x600,
1024x768,
-> 1168x876,
1152x900,
1280x1024
[DESKTOPS]
640x480,
800x600,
1024x768,
1152x900,
-> 1168x876,
1280x1024,
1600x1200
If the dot clock is low enough ( NOT in this case for my board ) you can put the entry even in the 16bpp and 32bpp sec- tions.
The /etc/Xaccel.ini will look something like this
--------------------------------------------------------------
Board = "s3/764-2.xqa";
Monitor = "mfreq/mfreq64.vda";
Depth = 8;
-> Desktop = 1168x876;
[RESOLUTIONS]
-> 1168x876,
1024x768;
The actual Xinside mode entry in etc/Xtimings
--------------------------------------------------------------
[PREADJUSTED_TIMING]
PreadjustedTimingName = "1168x876 @ 72Hz";
HorPixel = 1168; // pixels
VerPixel = 876; // lines
PixelWidthRatio = 4;
PixelHeightRatio = 3;
HorFrequency = 64.024; // kHz
VerFrequency = 71.138; // Hz
ScanType = NONINTERLACED;
HorSyncPolarity = POSITIVE;
VerSyncPolarity = POSITIVE;
CharacterWidth = 8; // pixels
PixelClock = 105.000; // MHz
HorTotalTime = 15.619; // (usec) = 205 chars
HorAddrTime = 11.124; // (usec) = 146 chars
HorBlankStart = 11.124; // (usec) = 146 chars
HorBlankTime = 4.495; // (usec) = 59 chars
HorSyncStart = 11.962; // (usec) = 157 chars
HorSyncTime = 2.743; // (usec) = 36 chars
VerTotalTime = 14.057; // (msec) = 900 lines
VerAddrTime = 13.682; // (msec) = 876 lines
VerBlankStart = 13.682; // (msec) = 876 lines
VerBlankTime = 0.375; // (msec) = 24 lines
VerSyncStart = 13.698; // (msec) = 877 lines
VerSyncTime = 0.219; // (msec) = 14 lines
You can check your conversion by running the vgaset program with no parameters while running the Xinside server: it will output an XFree-like line and, if everything went OK, this line will be equal to the line you started from ( except if b and c are equal, I haven't been able to reproduce this situation in Xinside: the best case was c=b+1 ).