ATI Adapters README file
Marc Aurele La France
2002 February 12
This is the README for the ATI Mach64 driver included in this release.
______________________________________________________________________
Table of Contents
1. Statement of intent
2. A note on acceleration
3. Current implementation for ATI adapters
4. Current implementation of generic VGA support for non-ATI adapters
5. xorg.conf specifications
5.1 Driver ``ati''
5.2 ChipSet ``name''
5.3 ChipID & ChipRev specifications
5.4 IOBase
5.5 BusID
5.6 Clocks
5.6.1 Clocks for supported programmable clock generators
5.6.2 Clocks for unsupported programmable clock generators
5.6.3 Clocks for fixed clock generators on ATI adapters
5.6.4 Clocks for non-ATI adapters
5.7 Option ``nopanel_display''
5.8 Option ``crt_display''
5.9 Option ``noaccel''
5.10 Option ``nolinear''
5.11 Option ``HWCursor'' and Option ``SWCursor''
5.12 Option ``SilkenMouse''
5.13 Option ``shadowfb''
5.14 Option ``dpms''
5.15 Option ``backingstore''
5.16 MemBase address
5.17 Option ``ReferenceClock'' ``frequency''
5.18 ClockChip ``name''
6. Video modes
7. Known problems and limitations
8. Reporting problems
9. Driver history
10. Driver versions
______________________________________________________________________
1. Statement of intent
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 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.
The driver will provide
o accelerated support if an ATI accelerator is detected and the user
has not requested that this support be disabled; otherwise
o accelerated support if a non-ATI 8514/A-capable adapter is detected
and the user has requested such support; otherwise
o unaccelerated SuperVGA support if an ATI VGA-capable adapter is
detected; otherwise
o generic VGA support if a non-ATI VGA-capable adapter is detected
and the user has requested such support.
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 ``xorg.conf specifications''
section below for details.
If none of the above conditions are met, the ATI driver will
essentially disable itself to allow other drivers to examine the
system.
2. A note on acceleration
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.
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.
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.
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.
3. Current implementation for ATI adapters
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:
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)
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).
The newer Rage 128 and Radeon chips are not 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.
Adapters based on the above chips have been marketed under a rather
large number of names over the years. Among them are:
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
Also, a number of mainboards, laptops and notebooks harbour a Mach32
or Mach64 controller.
VGAWonder, Mach8 and Mach32 ISA adapters are available with or without
a mouse.
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.
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.
The driver does 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.
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.
On non-Intel platforms, the driver can, currently, only support PCI
Mach64 adapters.
4. Current implementation of generic VGA support for non-ATI adapters
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.
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.
The driver will enforce the following limitations derived from IBM's
original VGA implementation:
o There can only be a set of four (non-programmable) clocks to choose
from.
o Video memory is limited to 256kB in monochrome and 16-colour modes.
o Video memory is limited to 64kB in 256-colour modes.
o Interlaced modes are not available.
o Colour depths higher than 8 are not available.
5. xorg.conf specifications
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.
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.
Other options affect the driver's operation once an adapter has been
assigned to the ``Device'' section which contains them.
5.1. Driver ``ati''
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.
5.2. ChipSet ``name''
The default ChipSet name for this driver is ``ati''. 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.
If ``ativga'' is specified instead, the driver will ignore any ATI
accelerator it detects, but otherwise operate as if ``ati'' had been
specified. This specification ensures the VGA CRTC is used.
A ChipSet name of ``ibmvga'' 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 ``ativga'' had been specified instead.
A ChipSet name of ``vgawonder'' is equivalent to ``ativga'', except
that only VGAWonder-capable adapters can be assigned to the ``Device''
section. This specifically excludes the newer integrated Mach64
controllers.
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
``mach32'' or ``mach64'', 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 ``ati''.
On non-Intel platforms, only ``ati'' and ``mach64'' ChipSet values are
operative.
5.3. ChipID & ChipRev specifications
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.
5.4. IOBase
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.
5.5. BusID
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.
5.6. Clocks
For the purpose of specifying a clock line in your xorg.conf, one of
four different situations can occur, as follows.
Those configuring the driver's generic VGA support for a non-ATI
adapter, can skip ahead to the ``Clocks for non-ATI adapters'' section
below. Those not trying to configure the driver for a Mach64 adapter,
can skip ahead to the ``Clocks for fixed clock generators on ATI
adapters'' section below.
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
``Clocks for fixed clock generators on ATI adapters'' section below.
The two cases that are left deal with programmable clock generators,
which are used on the great majority of Mach64 adapters.
If you are uncertain which situation applies to your adapter, you can
run a clock probe with the command ``X -probeonly''.
5.6.1. Clocks for supported programmable clock generators
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.
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.
5.6.2. Clocks for unsupported programmable clock generators
This case is unlikely to occur, but is documented for the sake of
completeness.
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:
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
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
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
If the driver matches the clocks to the third setting above, function-
ality will be extremely limited (assuming the driver works at all).
5.6.3. Clocks for fixed clock generators on ATI adapters
This section applies to all VGAWonder and Mach32 adapters, and to
early Mach64 prototypes.
One of the following clocks specifications (or an initial subset
thereof) can be used depending on what the adapter uses to generate
dot clocks:
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
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
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
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
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
VGAWonder VLB, VGA 1024 VLB, Mach32 and Mach64 owners should only
specify up to the first 32 frequencies. Any more will be ignored.
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.
The order of the clocks is 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.
5.6.4. Clocks for non-ATI adapters
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.
5.7. Option ``nopanel_display''
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.
5.8. Option ``crt_display''
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.
5.9. Option ``noaccel''
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.
5.10. Option ``nolinear''
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.
On non-Intel platforms, the driver requires a linear aperture and, so,
this option is ignored.
5.11. Option ``HWCursor'' and Option ``SWCursor''
Option ``HWCursor'', which is the default, specifies that hardware
facilities are to be used to paint the mouse pointer on the screen.
Option ``SWCursor'' specifies that the mouse pointer is to be drawn by
software, which is much slower. If both options are specified, option
``SWCursor'' 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.
5.12. Option ``SilkenMouse''
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.
5.13. Option ``shadowfb''
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.
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.
5.14. Option ``dpms''
This option enables the driver's support for VESA's Display Power
Management Specification.
5.15. Option ``backingstore''
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.
5.16. MemBase address
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.
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.
5.17. Option ``ReferenceClock'' ``frequency''
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.
5.18. ClockChip ``name''
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 ``ATI 18818-0'' or
``ATI 18818-1''. 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 ``Clocks for unsupported programmable clock generators''
above.
6. Video modes
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.).
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.
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 "Native panel mode" that
represents the panel's native resolution.
7. Known problems and limitations
There are several known problems or limitations related to the ATI
driver. They include:
o 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.
o 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.
o Due to hardware limitations, doublescanned modes are not supported
by the accelerator CRTC in 88800GX, 88800CX, 264CT and 264ET
adapters.
o The ``VScan'' modeline parameter is only supported when using the
VGA CRTC.
o 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.
o 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.
o 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, xrefresh(1) 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.
o 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.
o 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.
o 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.
o 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.
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.
Support for the following will be added in a future release:
o Mach32's accelerator CRTC. This support is the first step towards
accelerated support for Mach32's, Mach8's, 8514/A's and other
clones.
o Colour depth greater than 8 on non-integrated controllers, where
permitted by the hardware.
o Mach32, Mach8 and 8514/A Draw Engines.
o Hardware cursors where implemented by hardware. This has already
been done for Mach64 integrated controllers.
o TVOut, i.e. the ability to use a television screen as a monitor.
o Motion Video, i.e. displaying an asynchronous data stream (TV
signal, DVD, etc.) in a window or full-screen.
o 3D operations.
8. Reporting problems
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 http://www.x.org/releases/individual/
if you are uncertain.
Secondly, please check Xorg's doc directory for additional
information.
Thirdly, a scan through the comp.windows.x.i386unix and
comp.os.linux.x newsgroups, the xorg mailing list archives at
http://lists.freedesktop.org/mailman/listinfo/xorg, and the Xorg bug
database at https://bugs.freedesktop.org/enter_bug.cgi?product=xorg
can also prove useful in resolving problems.
If you are still experiencing problems, you can send non-HTMLised e-
mail to <mailto:xorg@lists.fredesktop.org>. Please be as specific as
possible when describing the problem(s), and include an unedited copy
of the server's log and the xorg.conf file used.
9. Driver history
The complete history of the driver is rather cloudy. The following is
more than likely to be incomplete and inaccurate.
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).
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.
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.
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.
10. Driver versions
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.
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.
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.
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.
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.
Version 5 is an almost complete restructuring of version 4 to fit in
the newer driver API of XFree86 4.0 and later.
The introduction of version 6 is a first swipe at porting the driver
to non-Intel architectures.
All questions regarding this software should be directed at the
Xorg mailing list:
http://lists.freedesktop.org/mailman/listinfo/xorg
Please submit bug reports to the Xorg bugzilla:
https://bugs.freedesktop.org/enter_bug.cgi?product=xorg
The master development code repository can be found at:
git://anongit.freedesktop.org/git/xorg/driver/xf86-video-mach64
http://cgit.freedesktop.org/xorg/driver/xf86-video-mach64
For patch submission instructions, see:
http://www.x.org/wiki/Development/Documentation/SubmittingPatches
For more information on the git code manager, see:
http://wiki.x.org/wiki/GitPage
