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- Information for Trident Chipset Users
- The XFree86 Project, Inc.
- 16 February 1996
-
- 1. Supported chipsets
-
- The Trident driver has undergone major work for XFree86 3.1.2B.
- Because of this work, all of the Trident SVGA chipsets, except the
- very first one, are supported by both the color and monochrome
- servers.
-
- 8800CS 8200LX 8900B 8900C 8900CL/D 9000 9000i 9100B 9200CXr
- 9320LCD 9400CXi 9420 9420DGi 9430DGi 9440AGi 9660XGi 9680
-
-
- It must be noted that the 9000i chipset is treated as a 9000 by the
- server. Additionally the 9100B is treated as a Trident 8900CL. There-
- fore it is equivalent to putting `Chipset "tvga8900cl"' or `Chipset
- "tvga9000"' in the XF86Config file. Also, note that the 9000i, 9100B
- have not been tested with the server, but should work in this way
- according to the chipset documentation.
-
- NOTES:
-
- o The TGUI9440/9660/9680 are now fully supported by the SVGA
- server.
-
- o 16 bits per pixel is now supported for the 8900D, 9200CXr,
- 9400CXi, 9420DGi, 9430DGi, 9440AGi, 9660XGi and 9680, but only
- the 9440AGi and 9400CXi have been tested.
-
- o Linear access has been implemented for chipsets that support it.
- It is enabled by default for PCI cards, and disabled by default
- for other cards. Additionally Hardware cursor is implemented
- for the 9430, 9440, 9660 and 9680, although only the 9440 and
- 9660 have been tested with the hardware cursor.
-
- o The following options may be specified for the Trident driver:
-
- Option "nolinear"
- Turn off linear mapping
-
- Option "linear"
- Force linear mapping. Use this if you have a non-PCI card
- and require 16bpp support. Note: ISA cards can only access
- up to 16MB of memory, so be sure you have less than this or
- it could cause a system hang.
-
- MemBase "0x???????"
- This option may be used to specify the start address of the
- linear frame buffer. By default for VLBus/EISA cards it is at
- 60MB. For the 8900CL/D, it is at 15MB.
-
- Option "fast_dram"
- 45ns DRAM
-
- Option "med_dram"
- 70ns DRAM
-
- Option "slow_dram"
- 80ns DRAM. This is the default for TGUIs.
-
- Option "hw_cursor"
- Turn on hardware cursor (NOTE: it is off by default)
-
-
- Option "tgui_pci_read_on"
- Turn on PCI burst read mode.
-
- Option "tgui_pci_read_off"
- Turn off PCI burst read mode.
-
- Option "tgui_pci_write_on"
- Turn on PCI burst write mode.
-
- Option "tgui_pci_write_off"
- Turn off PCI burst write mode. NOTE: PCI modes. By default
- the read burst and write burst are independent of each other.
- By not specifying one of the above - the PCI registers are
- untouched. If you suffer from screen corruption then try
- turning them off. By turning them on explicitly may benefit
- from improved performance, but it may also give screen
- corruption. USE WITH CAUTION.
-
- ClockChip "tgui"
- Turn on programmable clocks. This is the default for TGUIs.
-
- Option "no_program_clocks"
- Turn off programmable clock. Use fixed VGA clocks only.
- Useful for fixed frequency monitors - usually used for VGA
- monitors - not SVGA.
-
- o No acceleration features of the newer chipsets have been taken
- advantage of yet!
-
- The original Trident chipset, 8800BR, cannot be supported as an SVGA
- chipset by either the color or monochrome servers. The chip is
- supported, however, by the ``generic'' driver for the monochrome
- server.
-
- 2. Special considerations for 512k boards
-
- There are no longer any special considerations for 512k Trident
- boards. The driver is now configured so that they can use modes with
- normal timings. The available pixel clocks are halved compared with
- those specified on the Clocks line
-
- Be aware that older Trident chipsets support a maximum clock of 65Mhz.
- Hence the best actual clock available to the color server is 32.5Mhz.
- This means, in broad terms, that the color server will require an
- interlaced mode to be defined for resolutions above 640x480. Newer
- chipsets (8900CL, 9000, 9000i, 9100B, 9200CX and 9420) support up to
- 16 clocks, and can support much higher clocks, which will allow
- 800x600 modes, non-interlaced.
-
- 3. Additional Notes
-
- We have had reports of the server failing to detect the amount of
- installed memory and the correct dot-clocks on older TVGA8900 boards.
- If the server fails to detect the correct amount of memory, use the
- "Videoram" keyword in your XF86Config file to specify it. (e.g.
- Videoram 512 or Videoram 1024). If the server has problems detecting
- the dot-clocks, try adding the following line to your XF86Config file:
-
- Clocks 25 28 45 36 57 65 50 40
-
-
- This line gives the clock values provided by older Trident clock syn-
- thesizer chipsets. This also appears to be the standard first 8
- clocks for the newer clock synthesizers, but you should have no prob-
- lems on newer boards.
-
- Some newer Trident 8900B/C boards are apparently being built with the
- clock synthesizers used on the 9000 and 8900CL boards. If your board
- has a chip labeled "Trident TCK900x" ("x" has been seen as 2 or 4;
- there may be others), your board may actually have a 4th clock select
- bit. The 9002 has twelve distinct clocks (the other 4 are
- duplicates); the 9004 has 16 clocks (the same 12 as the 9002 + 4
- others). If you see such a chip on a board with an 8900B or 8900C,
- put the following line in the Device section of your XF86Config file:
-
- Option "16clocks"
-
-
- This will cause the same clock selection code as is used for the
- 8900CL to be used for the board.
-
- While developing the Trident driver, an interesting and perturbing
- hardware phenomenon was discovered. When using the default board
- jumper configuration, dot-clocks above 57Mhz would frequently lock up
- the machine. There appear to be jumpers on all of the Trident boards
- that determine whether the board will operate in zero-wait-state mode
- on the ISA bus. Disabling the zero-wait-state mode via jumpers cured
- the lockups, but at the expense of performance. Whether or not a
- given system will experience this problem is likely a combination of
- (a) bus speed, (b) video memory speed, and (c) dot clock speed. So be
- prepared for this phenomenon to occur, and have the board
- documentation handy.
-
- NOTE: VLBus cards are also subject to the above. By specifying the
- Clocks in the XF86Config file, these lockups are overcome. But it may
- be worth checking wait states etc. on the card and in the BIOS setup.
-
-
- Generated from XFree86: xc/programs/Xserver/hw/xfree86/doc/sgml/trident.sgml,v 3.13 1996/08/26 14:08:49 dawes Exp $
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- $XFree86: xc/programs/Xserver/hw/xfree86/doc/README.trident,v 3.21 1996/08/26 14:23:46 dawes Exp $
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