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-<!DOCTYPE linuxdoc PUBLIC "-//Xorg//DTD linuxdoc//EN"[
-<!ENTITY % defs SYSTEM "defs.ent"> %defs;
-]>
-
-<article>
-
-<!-- Title information -->
-
-<title>ATI Adapters README file
-<author>Marc Aurele La France
-<date>2002 February 12
-
-
-
-
-
-<ident>
-$Id$
-Based on XFree86: xc/programs/Xserver/hw/xfree86/doc/sgml/ati.sgml,v 3.42 2003/01/20 03:43:07 dawes Exp
-</ident>
-
-<abstract>
-This is the README for the XAA ATI driver included in this release.
-</abstract>
-
-<!-- Table of contents -->
-<toc>
-
-<!-- Begin the document -->
-
-<sect>Statement of intent<p>
-Generally speaking, the driver is intended for all ATI video adapters
-based on the Mach64 series or older chipsets,
-providing maximum video function within hardware limitations.
-The driver is also intended to optionally provide the same level of support for
-generic VGA or 8514/A adapters.
-The newer Rage 128 and Radeon chips are not yet supported by this driver.
-Rage 128's and Radeon's are, however, supported by separate drivers, and
-owners of such adapters should consult the documentation provided with these
-drivers.
-This driver will also invoke the appropriate driver if it finds Rage 128 and/or
-Radeon adapter(s) in the system.
-This driver is still being actively developed, meaning that it currently does
-not yet fully meet these goals.<p>
-The driver will provide
-<itemize>
-<item>accelerated support if an ATI accelerator is detected <it>and</it> the
-user has not requested that this support be disabled; otherwise
-<item>accelerated support if a non-ATI 8514/A-capable adapter is detected
-<it>and</it> the user has requested such support; otherwise
-<item>unaccelerated SuperVGA support if an ATI VGA-capable adapter is detected;
-otherwise
-<item>generic VGA support if a non-ATI VGA-capable adapter is detected
-<it>and</it> the user has requested such support.
-</itemize>
-Thus, the level of support provided not only depends on what the driver detects
-in the system, but also, on what the user specifies in the xorg.conf file.
-See the <bf>``xorg.conf specifications''</bf> section below for details.<p>
-If none of the above conditions are met, the ATI driver will essentially
-disable itself to allow other drivers to examine the system.<p>
-<!--
-Note that I am currently considering removing the driver's support for generic
-VGA.
-If you have any concerns about this, please contact me at
-<email>tsi@xfree86.org</email>.
--->
-<sect>A note on acceleration<p>
-The meaning of ``acceleration'', as used in this document, needs to be
-clarified.
-Two of the many components in an accelerator are the CRT controller (CRTC) and
-the Draw Engine.
-This is in addition to another CRTC that, generally, is also present in the
-system (often in the same chip) and typically provides EGA, VGA or SuperVGA
-functionality.<p>
-A CRTC is the component of a graphics controller that is responsible for
-reading video memory for output to the screen.
-A Draw Engine is an accelerator component that can be programmed to manipulate
-video memory contents, thus freeing the CPU for other tasks.<p>
-When the VGA CRTC is used, all drawing operations into video memory are the
-responsibility of the system's CPU, i.e. no Draw Engine can be used.
-On the other hand, if the accelerator's CRTC is chosen to drive the screen,
-the Draw Engine can also be used for drawing operations, although the CPU can
-still be used for this purpose if it can access the accelerator's video
-memory.<p>
-Video acceleration refers to the programming of an accelerator's Draw Engine to
-offload drawing operations from the CPU, and thus also implies the use of the
-accelerator's CRTC.<p>
-<sect>Current implementation for ATI adapters<p>
-The driver currently supports the SuperVGA capabilities of all ATI adapters
-except some early Mach8 and Mach32 adapters that do not provide the required
-functionality.
-This support works for monochrome, 16-colour and 256-colour video modes, if one
-of the following ATI graphics controller chips is present:
-<verb>
-VGAWonder series: 18800, 18800-1, 28800-2, 28800-4, 28800-5, 28800-6
- Mach32 series: 68800-3, 68800-6, 68800AX, 68800LX
- Mach64 series: 88800GX-C, 88800GX-D, 88800GX-E, 88800GX-F, 88800CX,
- 264CT, 264ET, 264VT, 264GT (3D Rage), 264VT-B, 264VT3,
- 264VT4, 264GT-B (3D Rage II), 3D Rage IIc, 3D Rage Pro,
- 3D Rage LT, 3D Rage LT Pro, 3D Rage XL, 3D Rage XC,
- 3D Rage Mobility (including the -M and -P variants)</verb>
-The driver also supports 32K, 64K and 16M-colour modes on the 264xT and 3D Rage
-series of adapters using the accelerator CRTC (but not the VGA CRTC).<p>
-The newer Rage 128 and Radeon chips are not yet supported by this driver.
-Rage 128's and Radeon's are, however, supported by separate drivers, and
-owners of such adapters should consult the documentation provided with these
-drivers.
-This driver will also invoke the appropriate driver if it finds Rage 128 and/or
-Radeon adapter(s) in the system.<p>
-Adapters based on the above chips have been marketed under a rather large
-number of names over the years.
-Among them are:
-<verb>
-VGAWonder series: VGAWonder V3, VGAWonder V4, VGAWonder V5, VGAWonder+,
- VGAWonder XL, VGAWonder XL24, VGAWonder VLB, VGA Basic,
- VGA Basic 16, VGA Edge, VGA Edge 16, VGA Integra,
- VGA Charger, VGAStereo F/X, VGA 640, VGA 800, VGA 1024,
- VGA 1024D, VGA 1024 XL, VGA 1024 DXL, VGA 1024 VLB
- Mach8 series: Graphics Ultra, Graphics Vantage, VGAWonder GT
- (None of the 8514/Ultra and 8514 Vantage series is
- supported at this time)
- Mach32 series: Graphics Ultra+, Graphics Ultra Pro, Graphics Wonder,
- Graphics Ultra XLR, Graphics Ultra AXO, VLB mach32-D,
- PCI mach32-D, ISA mach32
- Mach64 series: Graphics Xpression, Graphics Pro Turbo, WinBoost,
- WinTurbo, Graphics Pro Turbo 1600, Video Xpression,
- 3D Xpression, Video Xpression+, 3D Xpression+,
- 3D Charger, Video Charger, WinCharger, All-In-Wonder,
- All-In-Wonder PRO, 3D Pro Turbo, XPERT@Play,
- XPERT@Play 98, XPERT@Work, XPERT 98, XPERT LCD,
- XPERT XL</verb>
-Also, a number of mainboards, laptops and notebooks harbour a Mach32 or Mach64
-controller.<p>
-VGAWonder, Mach8 and Mach32 ISA adapters are available with or without a
-mouse.<p>
-These adapters are available with a variety of clock generators and RAMDACs.
-The 264xT and 3D Rage series of chips are integrated controllers, meaning that
-they include a programmable clock generator and a RAMDAC.<p>
-For all but Mach64 adapters, this driver still does not provide support for
-accelerated drawing to the screen.
-This means that all drawing is done by the CPU, rather than by any accelerator
-present in the system.
-This can make opaque moves, for example, quite ``jerky''.
-Also, given that IBM 8514/A and ATI Mach8 do not allow CPU access to their
-frame buffer, the driver will currently ignore these accelerators.
-Most Mach32 adapters provide both accelerated function and SuperVGA
-functionality, but the driver currently only uses the VGA.<p>
-The driver <it>does</it> however support the accelerator CRTC present in all
-ATI Mach64 adapters.
-For 256-colour, and higher depth modes, this support will be used by default,
-although an xorg.conf option can be specified to use the SuperVGA CRTC
-instead.
-A linear video memory aperture is also available in 256-colour and higher depth
-modes and enabled by default if a 264xT or 3D Rage controller is detected or,
-on 88800 controllers, if the accelerator CRTC is used.
-xorg.conf options are available to disable this aperture, or (for non-PCI
-adapters) enable it or move it to some other address.<p>
-By default, the driver provides some acceleration for Mach64 if the accelerator
-CRTC is used, and modes whose colour depth greater than or equal to 8 are to be
-used.
-This support is as yet incomplete and can be disabled entirely with an
-xorg.conf option.<p>
-On non-Intel platforms, the driver can, currently, only support PCI Mach64
-adapters.<p>
-<sect>Current implementation of generic VGA support for non-ATI adapters<p>
-Support for generic VGA with non-ATI adapters is also implemented, but has
-undergone only limited testing.
-The driver will intentionally disallow the use of this support with ATI
-adapters.
-This support must be explicitly requested through an xorg.conf ChipSet
-specification.
-This prevents the current VGA generic driver from being disabled.<p>
-This driver's generic VGA support is intended as an extension of that provided
-by the current generic driver.
-Specifically, within the architectural bounds defined by IBM's VGA standard,
-this driver will allow the use of any 256-colour mode, and any dot clock
-frequencies both of which allow for many more mode possibilities.<p>
-The driver will enforce the following limitations derived from IBM's original
-VGA implementation:
-<itemize>
-<item>There can only be a set of four (non-programmable) clocks to choose from.
-<item>Video memory is limited to 256kB in monochrome and 16-colour modes.
-<item>Video memory is limited to 64kB in 256-colour modes.
-<item>Interlaced modes are not available.
-<item>Colour depths higher than 8 are not available.
-</itemize>
-<sect>xorg.conf specifications<p>
-The driver recognises a number of xorg.conf options.
-In general, all such options should be specified in a ``Device'' section, and
-affect only that ``Device'' section.<p>
-Those options that affect how the driver associates adapters with ``Device''
-sections are described first.
-The driver will ignore (with a message) a ``Device'' section if the section
-cannot be associated with exactly one adapter in the system.
-Similarly, the driver will ignore, or disable, (with a message) any adapter
-that cannot be associated with exactly one ``Device'' section.
-Thus, these options will be required in those uncommon cases where such unique
-associations cannot automatically be made by the driver.<p>
-Other options affect the driver's operation once an adapter has been assigned
-to the ``Device'' section which contains them.<p>
-<sect1>Driver ``ati''<p>
-The use of this specification is highly recommended if the ``Device'' section
-is to be recognised by the driver.
-In fact, it is almost (but not quite) mandatory, particularly when using the
-loader server as it indicates what driver is to be loaded and associated with
-the ``Device'' section.<p>
-<sect1>ChipSet ``name''<p>
-The default ChipSet name for this driver is ``<it>ati</it>''.
-In this case, any ATI adapter can be associated with the ``Device'' section.
-If an ATI accelerator is detected and the driver supports it, the accelerator's
-CRTC will be used to drive the screen.
-Otherwise, the driver will programme the adapter's SuperVGA CRTC.<p>
-If ``<it>ativga</it>'' is specified instead, the driver will ignore any ATI
-accelerator it detects, but otherwise operate as if ``<it>ati</it>'' had been
-specified.
-This specification ensures the VGA CRTC is used.<p>
-A ChipSet name of ``<it>ibmvga</it>'' causes any VGA-capable adapter in the
-system to be associated with the ``Device'' section.
-It enables the driver's generic VGA support, but only for non-ATI adapters.
-If an ATI adapter is associated with the ``Device'' section, the driver will
-operate as if ``<it>ativga</it>'' had been specified instead.<p>
-A ChipSet name of ``<it>vgawonder</it>'' is equivalent to ``<it>ativga</it>'',
-except that only VGAWonder-capable adapters can be assigned to the ``Device''
-section.
-This specifically excludes the newer integrated Mach64 controllers.<p>
-In some PCI or AGP systems, the driver will not, by default, probe for non-PCI
-Mach32's or Mach64's.
-This is because, before doing any such probe, the driver attempts to determine
-if the probe can cause a lockup.
-If the driver has enough information to determine that a lockup would occur, it
-will skip the probe.
-In some situations, this determination cannot be accurate, and the driver will
-err on the side of caution, skipping the probe.
-Specifying a ChipSet name of ``<it>mach32</it>'' or ``<it>mach64</it>'', as
-appropriate, will force the driver to probe for the non-PCI adapter.
-These ChipSet names should, therefore, only be used when there is in fact such
-an adapter in the system.
-They are otherwise equivalent to ``<it>ati</it>''.<p>
-On non-Intel platforms, only ``<it>ati</it>'' and ``<it>mach64</it>'' ChipSet
-values are operative.<p>
-<sect1>ChipID & ChipRev specifications<p>
-These specifications will cause the driver to associate the ``Device'' section
-only with an adapter having the same attributes, or an adapter whose PCI device
-ID the driver does not recognise.
-In the second case, these options cause the driver to treat the adapter as if
-it was one with the specified PCI device ID or revision.
-ChipID can only be used with Mach32 or Mach64 adapters, and, thus, specifically
-excludes any other adapter from matching the ``Device'' section.
-ChipRev is meaningful only with Mach64 adapters, and then only if ChipID is
-also specified in the same ``Device'' section.<p>
-<sect1>IOBase<p>
-This option limits the adapters that can be associated with the ``Device''
-section to the one with the specified I/O base.
-This option only applies to Mach64 adapters and specifically excludes other
-adapters.<p>
-<sect1>BusID<p>
-This option limits the adapters that can be associated with the ``Device''
-section to the one with the specified PCI Bus ID.
-This specification excludes non-PCI adapters.<p>
-<sect1>Clocks<p>
-For the purpose of specifying a clock line in your xorg.conf, one of four
-different situations can occur, as follows.<p>
-Those configuring the driver's generic VGA support for a non-ATI adapter,
-can skip ahead to the <bf>``Clocks for non-ATI adapters''</bf> section below.
-Those <it>not</it> trying to configure the driver for a Mach64 adapter, can
-skip ahead to the <bf>``Clocks for fixed clock generators on ATI
-adapters''</bf> section below.<p>
-The very earliest Mach64 adapters use fixed (i.e. non-programmable) clock
-generators.
-Very few of these (mostly prototypes) are known to exist, but if you have one
-of these, you can also skip ahead to the <bf>``Clocks for fixed clock
-generators on ATI adapters''</bf> section below.<p>
-The two cases that are left deal with programmable clock generators, which are
-used on the great majority of Mach64 adapters.<p>
-If you are uncertain which situation applies to your adapter, you can run a
-clock probe with the command ``<tt>X -probeonly</tt>''.<p>
-<sect2>Clocks for supported programmable clock generators<p>
-At bootup, video BIOS initialisation programmes an initial set of frequencies.
-Two of these are reserved to allow the setting of modes that do not use a
-frequency from this initial set.
-One of these reserved slots is used by the BIOS mode set routine, the other by
-the particular driver used (e.g. MS-Windows, AutoCAD, X, etc.).
-The clock numbers reserved in this way are dependent on the particular clock
-generator used by the adapter.<p>
-The driver currently supports all programmable clock generators known to exist
-on Mach64 adapters.
-In this case, the driver will completely ignore any xorg.conf clock
-specification, and programme the clock generator as needed by the modes used
-during the X session.<p>
-<sect2>Clocks for unsupported programmable clock generators<p>
-This case is unlikely to occur, but is documented for the sake of
-completeness.<p>
-In this situation, the driver will probe the adapter for clock frequencies
-unless xorg.conf clocks are already specified.
-In either case, the driver will then attempt to normalise the clocks to one of
-the following specifications:
-<verb>
-BIOS setting 1:
-
- Clocks 0.000 110.000 126.000 135.000 50.350 56.640 63.000 72.000
- 0.000 80.000 75.000 65.000 40.000 44.900 49.500 50.000
- 0.000 55.000 63.000 67.500 25.180 28.320 31.500 36.000
- 0.000 40.000 37.500 32.500 20.000 22.450 24.750 25.000</verb>
-<verb>
-BIOS setting 2:
-
- Clocks 0.000 110.000 126.000 135.000 25.180 28.320 31.500 36.000
- 0.000 80.000 75.000 65.000 40.000 44.900 49.500 50.000
- 0.000 55.000 63.000 67.500 12.590 14.160 15.750 18.000
- 0.000 40.000 37.500 32.500 20.000 22.450 24.750 25.000</verb>
-<verb>
-BIOS setting 3:
-
- Clocks 0.000 0.000 0.000 0.000 25.180 28.320 0.000 0.000
- 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
- 0.000 0.000 0.000 0.000 12.590 14.160 0.000 0.000
- 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000</verb>
-If the driver matches the clocks to the third setting above, functionality will
-be <it>extremely</it> limited (assuming the driver works at all).<p>
-<sect2>Clocks for fixed clock generators on ATI adapters<p>
-This section applies to all VGAWonder and Mach32 adapters, and to early Mach64
-prototypes.<p>
-One of the following clocks specifications (or an initial subset thereof) can
-be used depending on what the adapter uses to generate dot clocks:
-<verb>
-Crystals (VGA Wonder V3 and V4 adapters only):
-
- Clocks 50.000 56.644 0.000 44.900 44.900 50.000 0.000 36.000
- 25.000 28.322 0.000 22.450 22.450 25.000 0.000 18.000
- 16.667 18.881 0.000 14.967 14.967 16.667 0.000 12.000
- 12.500 14.161 0.000 11.225 11.225 12.500 0.000 9.000</verb>
-<verb>
-ATI 18810 clock generator:
-
- Clocks 30.240 32.000 37.500 39.000 42.954 48.771 0.000 36.000
- 40.000 0.000 75.000 65.000 50.350 56.640 0.000 44.900
- 15.120 16.000 18.750 19.500 21.477 24.386 0.000 18.000
- 20.000 0.000 37.500 32.500 25.175 28.320 0.000 22.450
- 10.080 10.667 12.500 13.000 14.318 16.257 0.000 12.000
- 13.333 0.000 25.000 21.667 16.783 18.880 0.000 14.967
- 7.560 8.000 9.375 9.750 10.739 12.193 0.000 9.000
- 10.000 0.000 18.750 16.250 12.586 14.160 0.000 11.225</verb>
-<verb>
-ATI 18811-0 and ATI 18812-0 clock generators:
-
- Clocks 30.240 32.000 110.000 80.000 42.954 48.771 92.400 36.000
- 39.910 44.900 75.000 65.000 50.350 56.640 0.000 44.900
- 15.120 16.000 55.000 40.000 21.477 24.386 46.200 18.000
- 19.955 22.450 37.500 32.500 25.175 28.320 0.000 22.450
- 10.080 10.667 36.667 26.667 14.318 16.257 30.800 12.000
- 13.303 14.967 25.000 21.667 16.783 18.880 0.000 14.967
- 7.560 8.000 27.500 20.000 10.739 12.193 23.100 9.000
- 9.978 11.225 18.750 16.250 12.588 14.160 0.000 11.225</verb>
-<verb>
-ATI 18811-1 and ATI 18811-2 clock generators:
-
- Clocks 135.000 32.000 110.000 80.000 100.000 126.000 92.400 36.000
- 39.910 44.900 75.000 65.000 50.350 56.640 0.000 44.900
- 67.500 16.000 55.000 40.000 50.000 63.000 46.200 18.000
- 19.955 22.450 37.500 32.500 25.175 28.320 0.000 22.450
- 45.000 10.667 36.667 26.667 33.333 42.000 30.800 12.000
- 13.303 14.967 25.000 21.667 16.783 18.880 0.000 14.967
- 33.750 8.000 27.500 20.000 25.000 31.500 23.100 9.000
- 9.978 11.225 18.750 16.250 12.588 14.160 0.000 11.225</verb>
-<verb>
-ICS 2494-AM clock generators (found on some Dell motherboards):
-
- Clocks 75.000 77.500 80.000 90.000 25.175 28.322 31.500 36.000
- 100.000 110.000 126.000 135.000 40.000 44.900 50.000 65.000
- 37.500 38.750 40.000 45.000 12.588 14.161 15.750 18.000
- 50.000 55.000 63.000 67.500 20.000 22.450 25.000 32.500
- 25.000 25.833 26.667 30.000 8.392 9.441 10.500 12.000
- 33.333 36.667 42.000 45.000 13.333 14.767 16.667 21.667
- 18.750 19.375 20.000 22.500 6.294 7.081 7.875 9.000
- 25.000 27.500 31.500 33.750 10.000 11.225 12.500 16.250</verb>
-VGAWonder VLB, VGA 1024 VLB, Mach32 and Mach64 owners should only specify up to
-the first 32 frequencies.
-Any more will be ignored.<p>
-Other clock generators that have been used on ATI adapters (which can all be
-said to be clones of one of the above) might generate non-zero frequencies for
-those that are zero above, or vice-versa.<p>
-The order of the clocks <it>is</it> very important, although the driver will
-reorder the specified clocks if it deems it appropriate to do so.
-Mach32 and Mach64 owners should note that this order is different than what
-they would use for previous accelerated servers.<p>
-<sect2>Clocks for non-ATI adapters<p>
-If no clocks are specified in the xorg.conf, the driver will probe for four
-clocks, the second of which will be assumed to be 28.322 MHz.
-The first clock will typically be 25.175 MHz, but there are exceptions.
-You can include up to four clock frequencies in your xorg.conf to specify the
-actual values used by the adapter.
-Any more will be ignored.<p>
-<sect1>Option <it>``nopanel_display''</it><p>
-This specification is only effective when the driver detects that the adapter's
-BIOS has initialised both the digital flat panel and CRT interfaces.
-In such a situation, the driver will normally drive both the panel and the CRT.
-This specification causes the driver to disable the digital flat panel and
-display the screen image on the CRT instead, which could potentially allow for
-larger physical resolutions than the panel can handle.<p>
-<sect1>Option <it>``crt_display''</it><p>
-This specification is only effective when the driver detects that the adapter's
-BIOS has initialised the digital flat panel interface, but has disabled the
-CRT interface.
-In such a situation the driver will normally drive only the panel.
-This specification causes the driver to instead display the same image on both
-the panel and the CRT.<p>
-<sect1>Option <it>``noaccel''</it><p>
-By default, the driver will accelerate draw operations if a Mach64 CRTC is used
-to drive the display.
-As implemented in this driver, acceleration does not require a linear video
-memory aperture.
-This option disables this acceleration.<p>
-<sect1>Option <it>``nolinear''</it><p>
-By default, the driver will enable a linear video memory aperture for
-256-colour and higher depth modes if it is also using a Mach64 accelerator CRTC
-or an integrated Mach64 graphics chip.
-This option disables this linear aperture.<p>
-On non-Intel platforms, the driver requires a linear aperture and, so, this
-option is ignored.<p>
-<sect1>Option <it>``HWCursor''</it> and Option <it>``SWCursor''</it><p>
-Option <it>``HWCursor''</it>, which is the default, specifies that hardware
-facilities are to be used to paint the mouse pointer on the screen.
-Option <it>``SWCursor''</it> specifies that the mouse pointer is to be drawn by
-software, which is much slower.
-If both options are specified, option <it>``SWCursor''</it> prevails.
-Currently, these options are only acted upon for 256-colour or higher depth
-modes, if a Mach64 accelerator CRTC, or a Mach64 integrated controller is being
-used.
-In all other situations, a software cursor will be used, regardless of what
-these options specify.<p>
-<sect1>Option <it>``SilkenMouse''</it><p>
-This option is only acted upon when a hardware cursor is being used.
-It specifies that the cursor's position on the screen is to be updated as
-quickly as possible when the mouse is moved.
-This is the default behaviour.
-If this option is negated, the cursor may lag the mouse when the X server is
-very busy.<p>
-<sect1>Option <it>``shadowfb''</it><p>
-If this option is enabled, the driver will cause the CPU to do each drawing
-operation first into a shadow frame buffer in system virtual memory and then
-copy the result into video memory.
-If this option is not active, the CPU will draw directly into video memory.
-Enabling this option is beneficial for those systems where reading from video
-memory is, on average, slower than the corresponding read/modify/write
-operation in system virtual memory.
-This is normally the case for PCI or AGP adapters, and, so, this option is
-enabled by default.
-For other bus types, the default behaviour is to disable this option.<p>
-Note that, due to various limitations, this option is forcibly disabled when a
-linear video memory aperture is not enabled, when the frame buffer depth is
-less than 8, or when acceleration is used.<p>
-<sect1>Option <it>``dpms''</it><p>
-This option enables the driver's support for VESA's Display Power Management
-Specification.<p>
-<sect1>Option <it>``backingstore''</it><p>
-This is not specifically a driver option.
-It is used to enable the server's support for backing store, a mechanism by
-which pixel data for occluded window regions is remembered by the server
-thereby alleviating the need to send expose events to X clients when the data
-needs to be redisplayed.<p>
-<sect1>MemBase <it>address</it><p>
-This specification is only effective for non-PCI Mach64 adapters, and is used
-to override the CPU address at which the adapter will map its video memory.
-Normally, for non-PCI adapters, this address is set by a DOS install utility
-provided with the adapter.
-The MemBase option can also be used to enable the linear aperture in those
-cases where ATI's utility was not, or can not be, used.<p>
-For PCI and AGP adapters, this address is determined at system bootup according
-to the PCI Plug'n'Play specification which arbitrates the resource requirements
-of most devices in the system.
-This means the driver can not easily change the linear aperture address.<p>
-<sect1>Option <it>``ReferenceClock''</it> ``frequency''<p>
-This option is only applicable to non-Intel platforms, where an adapter BIOS is
-not available to the driver.
-The option specifies the reference frequency used by the adapter's clock
-generator.
-The default is 14.318 MHz, and other typical values are 28.636, or 29.5 MHz.<p>
-<sect1>ClockChip <it>``name''</it><p>
-This option is only applicable to non-Intel platforms, where an adapter BIOS is
-not available to the driver, and the driver cannot reliably determine whether
-the clock generator the adapter uses is a variant of an ATI 18818 (a.k.a.
-ICS 2595) or an unsupported clock generator.
-The only values that are acted upon are <it>``ATI 18818-0''</it> or
-<it>``ATI 18818-1''</it>.
-From this specification, the driver derives a reference divider of 43 or 46
-(respectively) for use in clock programming calculations.
-The driver's default behaviour, in this case, is to assume an unsupported clock
-generator, which means it will treat it as a fixed-frequency clock generator,
-as described under the heading <bf>``Clocks for unsupported programmable clock
-generators''</bf> above.<p>
-<sect>Video modes<p>
-Mode timings can be derived from the information in X's doc subdirectory.
-However, it is no longer required to specify such timings in an xorg.conf's
-``Monitor'' section(s), if only standard mode timings are to be used.
-The server automatically inserts VESA standard mode timings in every
-``Monitor'' section, and these modes will be checked first for mode constraints
-(monitor sync tolerances, video memory size, etc.).<p>
-Furthermore, it is also no longer required to specify mode names in ``Display''
-subsections.
-Should no mode names be specified (or those specified do not yield a usable
-mode), the server will automatically select as a default resolution the largest
-usable mode, whether or not the chosen mode is specified in the corresponding
-``Monitor'' section.<p>
-For a digital flat panel, any sync tolerances should be removed from the
-corresponding ``Monitor'' section.
-The driver will automatically calculate these from the mode that is active on
-server entry.
-The driver also inserts timings for a mode called <it>"Native panel mode"</it>
-that represents the panel's native resolution.<p>
-<sect>Known problems and limitations<p>
-There are several known problems or limitations related to the ATI
-driver.
-They include:<p>
-<itemize>
-<item>When using a Mach64's accelerator CRTC, the virtual resolution must be
-less than 8192 pixels wide.
-The VGA CRTC further limits the virtual resolution width to less than 4096
-pixels, or to less than 2048 pixels for adapters based on 18800-x's (with 256kB
-of memory) and on Mach64 integrated controllers.
-These are hardware limits that cannot be circumvented.
-<item>Virtual resolutions requiring more than 1MB of video memory (256kB in the
-monochrome case) are not supported by the VGA CRTC on 88800GX and 88800CX
-adapters.
-This is a hardware limit that cannot be circumvented.
-<item>Due to hardware limitations, doublescanned modes are not supported by the
-accelerator CRTC in 88800GX, 88800CX, 264CT and 264ET adapters.
-<item>The ``VScan'' modeline parameter is only supported when using the VGA
-CRTC.
-<item>Interlaced modes are not supported on 18800-x and 28800-x adapters when
-using a virtual resolution that is 2048 pixels or wider.
-When using a 18800-x with 256kB of video memory in 256-colour modes, this limit
-is reduced to 1024.
-This is yet another hardware limitation that cannot be circumvented.
-<item>Video memory banking does not work in monochrome and 16-colour modes on
-18800-x adapters.
-This appears to be another hardware limit, but this conclusion cannot be
-confirmed at this time.
-The driver's default behaviour in this case is to limit video memory to 256kB.
-<item>Video memory corruption can still occur during mode switches on 18800-x
-adapters.
-Symptoms of this problem include garbled fonts on return to text mode, and
-various effects (snow, dashed lines, etc) on initial entry into a graphics
-mode.
-In the first case, the workaround is to use some other means of restoring the
-text font.
-On Linux, this can be accomplished with the kbd or svgalib packages.
-In the second case, <htmlurl name="xrefresh(1)" url="xrefresh.1.html">
-will usually clean up the image.
-No complete solution to this problem is currently known.
-It appears this corruption occurs due to either video memory bandwidth or
-RAMDAC limitations, and so the driver will limit mode clocks to 40MHz.
-<item>There is some controversy over what the maximum allowed clock frequency
-should be on 264xT and 3D Rage adapters.
-For now, clocks will, by default, be limited to 80MHz, 135MHz, 170MHz, 200MHz
-or 230MHz, depending on the specific controller.
-This limit can only be increased (up to a driver-calculated absolute maximum)
-through the DACSpeed specification in xorg.conf.
-Be aware however that doing so is untested and might damage the adapter.
-<item>Except as in the previous items, clocks are limited to 80MHz on most
-adapters, although many are capable of higher frequencies.
-This will eventually be fixed in a future release.
-<item>The use of a laptop's hot-keys to switch displays while this driver is
-active can cause lockups and/or other woes, and is therefore not recommended.
-It is not currently possible to solve this problem.<p>
-<item>In situations where the driver is to simultaneously display on both a
-panel and a CRT, the same image will be seen on both.
-In particular, this means the CRT must be able to synchronise with the timings
-of the panel's native resolution.
-This is quite evident when the panel has ``odd-ball'' dimensions, such as
-1400x1050, a resolution not commonly possible on CRTs or projection
-equipment.<p>
-Also, the display of independent images on the panel and CRT is not currently
-implemented, and might never be, pending resolution of the previous item.<p>
-</itemize>
-Support for the following will be added in a future release:
-<itemize>
-<item>Mach32's accelerator CRTC.
-This support is the first step towards accelerated support for Mach32's,
-Mach8's, 8514/A's and other clones.
-<item>Colour depth greater than 8 on non-integrated controllers, where
-permitted by the hardware.
-<item>Mach32, Mach8 and 8514/A Draw Engines.
-<item>Hardware cursors where implemented by hardware.
-This has already been done for Mach64 integrated controllers.
-<item>TVOut, i.e. the ability to use a television screen as a monitor.
-<item>Motion Video, i.e. displaying an asynchronous data stream (TV signal,
-DVD, etc.) in a window or full-screen.
-<item>3D operations.
-</itemize>
-<sect>Reporting problems<p>
-If you are experiencing problems that are not already recorded in this
-document, first ensure that you have the latest current release of this driver
-and the Xorg X server.
-Check the server's log (usually found in /var/log/Xorg.0.log) and <htmlurl
-name="ftp://ftp.freedesktop.org/pub/Xorg"
-url="ftp://ftp.freedesktop.org/pub/Xorg"> if you are uncertain.<p>
-Secondly, please check Xorg's doc directory for additional information.<p>
-Thirdly, a scan through the comp.windows.x.i386unix and comp.os.linux.x
-newsgroups, the xorg mailing list archives at <htmlurl
-name="http://lists.freedesktop.org/mailman/listinfo/xorg"
-url="http://lists.freedesktop.org/mailman/listinfo/xorg">, and
-the Xorg bug database at <htmlurl
-name="https://bugs.freedesktop.org/enter_bug.cgi?product=xorg"
-url="https://bugs.freedesktop.org/enter_bug.cgi?product=xorg">
-can also prove useful in resolving problems.<p>
-If you are still experiencing problems, you can send <it>non-HTMLised</it>
-e-mail to <email>xorg@lists.fredesktop.org</email>.
-Please be as specific as possible when describing the problem(s), and include
-an <it>unedited</it> copy of the server's log and the xorg.conf file used.<p>
-<sect>Driver history<p>
-The complete history of the driver is rather cloudy.
-The following is more than likely to be incomplete and inaccurate.<p>
-Apparently, Per Lindqvist first got a driver working with an early ATI adapter
-under X386 1.1a.
-This original driver might have actually been based on a non-functional ATI
-driver written by Thomas Roell (currently of Xi Graphics).<p>
-Then Doug Evans added support for the ATI VGA Wonder XL, trying in the process
-to make the driver work with all other ATI adapters available at the time.<p>
-Rik Faith obtained the X11R4 driver from Doug Evans in the summer of 1992 and
-ported the code to the X386 part of X11R5.
-This subsequently became part of XFree86.<p>
-Marc Aurele La France took over development and maintenance of the driver
-in the fall of 1993 after Rik got rid of his VGA Wonder adapter.<p>
-<sect>Driver versions<p>
-Due to the introduction of loadable drivers in XFree86 4.0, it has become
-necessary to track driver versions separately.
-Driver releases use the following version numbering scheme.<p>
-Version 1 of this driver is the one I inherited from Rik Faith.
-This is the version found in XFree86 2.0 and 2.1.<p>
-Version 2 is my first rewrite of this code which only ended up being a
-partially unsuccessful attempt at generalising the driver for all VGA Wonder,
-Mach32, and early Mach64 adapters.
-Various releases of this version of the driver can be found in XFree86 2.1.1,
-3.1, 3.1.1 and 3.1.2.<p>
-Version 3 represents my second rewrite (although a rather lame one as rewrites
-go).
-Into version 3, I introduced clock programming for Mach64 adapters and merged
-in the old ati_test debugging tool.
-This is the version found in XFree86 3.2, 3.3 and 3.3.1.<p>
-Version 4 is a rather major restructuring of version 3, which became larger
-than I could comfortably handle in one source file.
-This is the version found in XFree86 3.3.2, 3.3.3, 3.3.3.1, 3.3.3.2, 3.3.4,
-3.3.5 and 3.3.6.<p>
-Version 5 is an almost complete restructuring of version 4 to fit in the newer
-driver API of XFree86 4.0 and later.<p>
-The introduction of version 6 is a first swipe at porting the driver to
-non-Intel architectures.<p>
-</article>