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s3(4x)									s3(4x)

       s3 - S3 video driver

       Section "Device"
	 Identifier "devname"
	 Driver	"s3"
	 [Option "optionname" ["optionvalue"]]

       The s3 driver supports PCI video	cards based on the following S3	chips:

       Trio32	   86C732

       Trio64	   86C764

       Trio64V+	   86C765

       Aurora64V+  86CM65

       Trio64UV+   86C767

       Trio64V2/DX 86C775

       Trio64V2/GX 86C785

       Vision964   86C964

       Vision968   86C968

       Also driver supports the	following RAMDACs:

       12     IBM 524, IBM 524A, IBM 526, IBM 526DB

       12     TI ViewPoint 3025

       s3 is an	Xorg driver for	S3 based video cards. The driver provides full
       accelerated support for the following colour depths: 8, 15, 16 and  24.
       The  overlay  video  (Xv)  is  supported	 in  depths  16	and 24 for the
       Trio64V+, Trio64UV+, Trio64V2/DX	and Trio64V2/GX	chips.

       Please refer to xorg.conf(5) for	general	configuration  details.	  This
       section	only covers configuration details specific to this driver. All
       options names are case and white	space insensitive when parsed  by  the
       server, for example, "trio 32/64" and "Trio32/64" are equivalent.

   Chip	overriding
       The  driver  auto-detects  the  chipset	and  RAMDAC, but the following
       Chipset names may optionally be specified  in  the  configuration  file
       "Device"	section, and will override the auto-detection:

	   "964-0", "964-1"  86C964 (rev.0 and rev.1)

	   "968"	     86C968

	   "Trio32/64"	     86C732/86C764

	   "Aurora64V+"	     86CM65

	   "Trio64UV+"	     86C767

	   "Trio64V2/DX/GX"  86C775/86C785

       The  86C765  (Trio64V+)	is Chipset "Trio32/64" with ChipRev greater or
       equal 0x40.

       An overriding of	RAMDAC auto-detection currently	is not implemented.

   Colour depth
       For every supported colour depth	the X server automatically selects  an
       appropriate number of bits per pixel (bpp) for framebuffer. The depth 8
       is represented by 8 bpp framebuffer (1 byte/pixel), the depths  15  and
       16  (respectively 5.5.5 and 5.6.5 pixel formats)	are represented	by the
       16 bpp framebuffer (2 bytes/pixel). Whenever the	depth  24  is  config-
       ured,  the  X  server  by  default  uses	 the  32  bpp  framebuffer  (4
       bytes/pixel), and the hardware is adjusted accordingly to  the  X.8.8.8
       pixel format, where X is	the ignored upper byte.

       As  the	second option for the depth 24,	the X server can be configured
       to use 24 bpp framebuffer with the 8.8.8	pixel format (3	 bytes/pixel),
       which is	supported by Trio64V+, Trio64UV+, Trio64V2/DX and Trio64V2/GX.
       If the video board has limited video RAM	the 24 bpp framebuffer has  an
       advantage  over	32 bpp framebuffer as it requires less memory to store
       screen, and, therefore, more space will be available for	a video	 frame
       (see  "Overlay video" section).	The 24 bpp framebuffer can be selected
       by X server's option -fbbpp 24 or by specifying DefaultFbBpp option  in

	   Section "Screen"
	     DefaultFbBpp 24
	     DefaultDepth 24

       However,	 the 24	bpp framebuffer	mode has the hardware limitations: (i)
       the 2D acceleration doesn't work	with this mode (use the	"shadowFB" op-
       tion  to	 speed	up  drawing routines in	this case); (ii) 24 bpp	frame-
       buffer cannot be	used with either  interlaced  or  doublescan  graphics

   Overlay video
       If  your	video board has	limited	RAM it would be	useful to estimate how
       large video frame might be placed in offscreen  video  memory.  Suppose
       that  the  video	 board	has 2 MB of RAM, and X server is configured to
       display 800x600 with the	depth 24. By default the  32  bpp  framebuffer
       will  be	 chosen	for this depth,	so 800 x 600 x 4 = 1875	kB will	be re-
       served for screen, and 2	MB - 1875 kB = 173 kB will remain for the off-
       screen  area.  This  is sufficient space, for example, for the VCD NTSC
       352x240 frame. If you need to upscale video with	a bigger frame,	but it
       doesn't fit the offscreen area, the only	way to do this is to lower ei-
       ther the	resolution or framebuffer's depth or both before the  viewing,
       otherwise,  you	will  get  the	allocation  error and will not see the
       video. For example, with	24 bpp framebuffer  and	 the  same  resolution
       800x600	the  offscreen area will be about 640 kB - it's	enough for the
       640x480 frame. 800x600 with the 16 bpp framebuffer gives	about 1110  kB
       of  offscreen area - this allows	to upscale up to 768x576 movies. Note,
       that all	movie resolutions in examples above are	provided as  a	refer-
       ence;  the movies can have the different	aspect ratios and non-standard
       dimensions. A total pixel amount	is the main consideration not the cer-
       tain width and height.

       Due to hardware limitation the overlay video will not work with the in-
       terlaced/doublescan modes. Downscaling is not implemented in hardware.

   Configuration options
       The following display Options are supported:

       Option "HWCursor" "boolean"
	      Enable or	disable	the hardware cursor. Currently,	hardware  cur-
	      sor  is not implemented, so the option will be ignored. Default:
	      off (software cursor).

       Option "NoAccel"	"boolean"
	      Disable acceleration. Very useful	for determining	if the	driver
	      has problems with	drawing	and acceleration routines. This	is the
	      first option to try if your server runs but you see graphic cor-
	      ruption  on  the	screen.	 Using it decreases performance, as it
	      uses software emulation for drawing operations the video	driver
	      can  accelerate with hardware. Default: off (acceleration	is en-

       Option "ShadowFB" "boolean"
	      Use shadow framebuffer. Disables hardware	acceleration. Use this
	      option  when the hardware	acceleration is	not available or unde-
	      sirable. Default:	off.

       Option "XVideo" "boolean"
	      Enable or	disable	Xv support. Default: on.

       The following video memory Options are supported:

       Option "slow_dram_refresh" "boolean"
	      Enable three refresh cycles per scanline.	Default: off (one  re-
	      fresh cycle).

       Option "slow_edodram" "boolean"
	      Switch to	2-cycle	EDO mode. Try this if you encounter pixel cor-
	      ruption. Using this option will cause a decrease in performance.
	      Default: off (BIOS defaults).

       Option "slow_dram" "boolean"
	      For Trio and Aurora64V+ chips: increase -RAS Precharge Timing to
	      3.5 MCLK.	Try this option	if you	encounter  pixel  errors.  De-
	      fault: off (BIOS defaults).

       Option "slow_vram" "boolean"
	      For  Vision964, Vision968	chips: increase	-RAS Low Timing	to 4.5
	      MCLK. Default: off (BIOS defaults).

       Xorg(1),	xorg.conf(5), Xserver(1), X(7)

       Thomas Roell, Mark Vojkovich, Kevin E. Martin, Amancio  Hasty,  Jon  N.
       Tombs  and  others were the original authors of driver for XFree86 3.x.
       Ani Joshi reworked driver for XFree86 4.x.  The	further	 modifications
       were  made  by  the  following contributors: Adam Jackson, Alan Cooper-
       smith, Dave Airlie, Andrew Radrianasulu,	Paulo  Cesar  Pereira  de  An-
       drade,  Eric  Anholt, SA,ren Sandmann Pedersen, Alex Deucher, Evgeny M.
       Zubok, Daniel Stone and others.

       The manual was written by Evgeny	M. Zubok <>

X Version 11		      xf86-video-s3 0.6.5			s3(4x)


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