Section "Monitor"
Identifier "mon1"
VendorName "SGI"
ModelName "1600sw"
HorizSync 31.5 - 121.0
VertRefresh 60-150
Modeline "1600x1024d32" 103.125 1600 1600 1656 1664 1024 1024 1029 1030 HSkew 7 +Hsync +Vsync
Modeline "1600x1024d16" 103.125 1600 1600 1656 1664 1024 1024 1029 1030 HSkew 5 +Hsync +Vsync
Modeline "1600x1024d08" 103.125 1600 1600 1656 1664 1024 1024 1029 1030 HSkew 1 +Hsync +Vsync
Modeline "800x512d32" 54.375 800 800 840 848 512 512 514 515 HSkew 7 DoubleScan +Hsync +Vsync
Modeline "800x512d16" 54.375 800 800 840 848 512 512 514 515 HSkew 5 DoubleScan +Hsync +Vsync
Modeline "800x512d08" 54.375 800 800 840 848 512 512 514 515 HSkew 1 DoubleScan +Hsync +Vsync
EndSection
Section "Screen"
Identifier "screen1"
Device "card1"
Monitor "mon1"
DefaultDepth 24
Subsection "Display"
Depth 08
Modes "1600x1024d08"
EndSubsection
Subsection "Display"
Depth 16
Modes "1600x1024d16"
EndSubsection
Subsection "Display"
Depth 24
Modes "1600x1024d32"
EndSubsection
EndSection
Note that the 800x512 modes only work with i128 driver, not with vesa.
But the i128 driver causes display managers (xdm, gdm) to hang the system on shutdown.
For pure desktop work vesa would be recommended, but for movie viewing i128 is better