In article <20030614020005.GA15246@olib.org>,
Richard Rauch <rkr@olib.org> wrote:
>Re. http://mail-index.netbsd.org/port-i386/2003/06/13/0005.html
>
>I think that what you describe is similar to some snow/static I see on
>my display (and S3Virge card in a regular tower PC).
>
>I know of two ways to get rid of it:
>
> * Turning off the XVideo extension (which, when enabled, seems to allow
>   higher performance graphic output to video memory).  This works, but
>   turning it off seems to affect performance.
>
> * I can also affect the impact that this has by changing video modes
>   (resolution and fresh frequency).

And a third is to turn the shadow framebuffer on. I've appended my config
file.

christos

>
>At the default mode for my card/monitory, there is always interference,
>even with an unchanging display.
>
>If I toggle one level "lower" on the resolution/frequency (winds up at
>the same resolution but presumably lower refresh rate), the display is
>*sometimes* okay.  By that, I mean that it is either rock-solid, or
>else it has *continuous* problems with ghosting/noise (the same as at
>the default/max res. & frequency).
>
>If I do things like switch to/from the virtual console with X, I can
>eventually get it to lock into a "good" display in this "second best"
>resolution/frequency.
>
>
>I've seen similar problems with a friend's GNU/LINUX box on an even
>older PC (my video card is from about 1997 or 1998).
>
>XFree86 definitely has some issues with trying to do too much sometimes.
>I assume that the cards are *capable* of doing what X is trying to
>make them do (e.g., my card "sometimes" works well), but maybe XFRee86
>is just not really able to tell if the hardware can handle some things,
>and they push ahead and hope for the best.
>
>Whatever the case, if you can't get a good display at an acceptable
>resolution, you might try turning off XVideo.  (Or turn it off anyway,
>if you don't use the system for playing video or such.)
>
# File generated by xf86config.

#
# Copyright (c) 1999 by The XFree86 Project, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
# THE XFREE86 PROJECT BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
# OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
# 
# Except as contained in this notice, the name of the XFree86 Project shall
# not be used in advertising or otherwise to promote the sale, use or other
# dealings in this Software without prior written authorization from the
# XFree86 Project.
#

# **********************************************************************
# Refer to the XF86Config(4/5) man page for details about the format of 
# this file.
# **********************************************************************

# **********************************************************************
# Module section -- this  section  is used to specify
# which dynamically loadable modules to load.
# **********************************************************************
#
Section "Module"

# This loads the DBE extension module.

    Load        "dbe"  	# Double buffer extension

# This loads the miscellaneous extensions module, and disables
# initialisation of the XFree86-DGA extension within that module.
    SubSection  "extmod"
      Option    "omit xfree86-dga"   # don't initialise the DGA extension
    EndSubSection

# This loads the Type1 and FreeType font modules
    Load        "type1"
    Load        "freetype"

# This loads the GLX module
#    Load       "glx"

EndSection

# **********************************************************************
# Files section.  This allows default font and rgb paths to be set
# **********************************************************************

Section "Files"

# The location of the RGB database.  Note, this is the name of the
# file minus the extension (like ".txt" or ".db").  There is normally
# no need to change the default.

    RgbPath	"/usr/X11R6/lib/X11/rgb"

# Multiple FontPath entries are allowed (which are concatenated together),
# as well as specifying multiple comma-separated entries in one FontPath
# command (or a combination of both methods)
# 
# If you don't have a floating point coprocessor and emacs, Mosaic or other
# programs take long to start up, try moving the Type1 and Speedo directory
# to the end of this list (or comment them out).
# 

    FontPath   "/usr/X11R6/lib/X11/fonts/local/"
    FontPath   "/usr/X11R6/lib/X11/fonts/misc/"
    FontPath   "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled"
    FontPath   "/usr/X11R6/lib/X11/fonts/100dpi/:unscaled"
    FontPath   "/usr/X11R6/lib/X11/fonts/Type1/"

# The module search path.  The default path is shown here.

#    ModulePath "/usr/X11R6/lib/modules"

EndSection

# **********************************************************************
# Server flags section.
# **********************************************************************

Section "ServerFlags"

# Uncomment this to cause a core dump at the spot where a signal is 
# received.  This may leave the console in an unusable state, but may
# provide a better stack trace in the core dump to aid in debugging

#    Option "NoTrapSignals"

# Uncomment this to disable the <Crtl><Alt><BS> server abort sequence
# This allows clients to receive this key event.

#    Option "DontZap"

# Uncomment this to disable the <Crtl><Alt><KP_+>/<KP_-> mode switching
# sequences.  This allows clients to receive these key events.

#    Option "Dont Zoom"

# Uncomment this to disable tuning with the xvidtune client. With
# it the client can still run and fetch card and monitor attributes,
# but it will not be allowed to change them. If it tries it will
# receive a protocol error.

#    Option "DisableVidModeExtension"

# Uncomment this to enable the use of a non-local xvidtune client. 

#    Option "AllowNonLocalXvidtune"

# Uncomment this to disable dynamically modifying the input device
# (mouse and keyboard) settings. 

#    Option "DisableModInDev"

# Uncomment this to enable the use of a non-local client to
# change the keyboard or mouse settings (currently only xset).

#    Option "AllowNonLocalModInDev"

EndSection

# **********************************************************************
# Input devices
# **********************************************************************

# **********************************************************************
# Core keyboard's InputDevice section
# **********************************************************************

Section "InputDevice"

    Identifier	"Keyboard1"
    Driver	"Keyboard"
# For most OSs the protocol can be omitted (it defaults to "Standard").
# When using XQUEUE (only for SVR3 and SVR4, but not Solaris),
# uncomment the following line.

#    Option     "Protocol"      "Xqueue"

    Option "AutoRepeat" "500 30"

# Specify which keyboard LEDs can be user-controlled (eg, with xset(1))
#    Option	"Xleds"      "1 2 3"

#    Option "LeftAlt"     "Meta"
#    Option "RightAlt"    "ModeShift"

# To customise the XKB settings to suit your keyboard, modify the
# lines below (which are the defaults).  For example, for a non-U.S.
# keyboard, you will probably want to use:
#    Option "XkbModel"    "pc102"
# If you have a US Microsoft Natural keyboard, you can use:
#    Option "XkbModel"    "microsoft"
#
# Then to change the language, change the Layout setting.
# For example, a german layout can be obtained with:
#    Option "XkbLayout"   "de"
# or:
#    Option "XkbLayout"   "de"
#    Option "XkbVariant"  "nodeadkeys"
#
# If you'd like to switch the positions of your capslock and
# control keys, use:
#    Option "XkbOptions"  "ctrl:swapcaps"

# These are the default XKB settings for XFree86
#    Option "XkbRules"    "xfree86"
#    Option "XkbModel"    "pc101"
#    Option "XkbLayout"   "us"
#    Option "XkbVariant"  ""
#    Option "XkbOptions"  ""

#    Option "XkbDisable"

    Option "XkbRules"	"xfree86"
    Option "XkbModel"	"pc105"
    Option "XkbLayout"	"us"

EndSection


# **********************************************************************
# Core Pointer's InputDevice section
# **********************************************************************

Section "InputDevice"

# Identifier and driver

    Identifier	"Mouse1"
    Driver	"mouse"
    Option "Protocol"    "wsmouse"
    Option "Device"      "/dev/wsmouse"
    Option "ZAxisMapping" "4 5"


# When using XQUEUE, comment out the above two lines, and uncomment
# the following line.

#    Option "Protocol"	"Xqueue"

# Baudrate and SampleRate are only for some Logitech mice. In
# almost every case these lines should be omitted.

#    Option "BaudRate"	"9600"
#    Option "SampleRate"	"150"

# Emulate3Buttons is an option for 2-button Microsoft mice
# Emulate3Timeout is the timeout in milliseconds (default is 50ms)

    Option "Emulate3Buttons"
#    Option "Emulate3Timeout"    "50"

# ChordMiddle is an option for some 3-button Logitech mice

#    Option "ChordMiddle"

EndSection


# **********************************************************************
# Other input device sections 
# this is optional and is required only if you
# are using extended input devices.  This is for example only.  Refer
# to the XF86Config man page for a description of the options.
# **********************************************************************
#
# Section "InputDevice" 
#    Identifier  "Mouse2"
#    Driver      "mouse"
#    Option      "Protocol"      "MouseMan"
#    Option      "Device"        "/dev/mouse2"
# EndSection
#
# Section "InputDevice"
#    Identifier "spaceball"
#    Driver     "magellan"
#    Option     "Device"        "/dev/cua0"
# EndSection
#
# Section "InputDevice"
#    Identifier "spaceball2"
#    Driver     "spaceorb"
#    Option     "Device"        "/dev/cua0"
# EndSection
#
# Section "InputDevice"
#    Identifier "touchscreen0"
#    Driver     "microtouch"
#    Option     "Device"        "/dev/ttyS0"
#    Option     "MinX"          "1412"
#    Option     "MaxX"          "15184"
#    Option     "MinY"          "15372"
#    Option     "MaxY"          "1230"
#    Option     "ScreenNumber"  "0"
#    Option     "ReportingMode" "Scaled"
#    Option     "ButtonNumber"  "1"
#    Option     "SendCoreEvents"
# EndSection
#
# Section "InputDevice"
#    Identifier "touchscreen1"
#    Driver     "elo2300"
#    Option     "Device"        "/dev/ttyS0"
#    Option     "MinX"          "231"
#    Option     "MaxX"          "3868"
#    Option     "MinY"          "3858"
#    Option     "MaxY"          "272"
#    Option     "ScreenNumber"  "0"
#    Option     "ReportingMode" "Scaled"
#    Option     "ButtonThreshold"       "17"
#    Option     "ButtonNumber"  "1"
#    Option     "SendCoreEvents"
# EndSection

# **********************************************************************
# Monitor section
# **********************************************************************

# Any number of monitor sections may be present

Section "Monitor"

    Identifier  "libretto"

# HorizSync is in kHz unless units are specified.
# HorizSync may be a comma separated list of discrete values, or a
# comma separated list of ranges of values.
# NOTE: THE VALUES HERE ARE EXAMPLES ONLY.  REFER TO YOUR MONITOR'S
# USER MANUAL FOR THE CORRECT NUMBERS.

    HorizSync   31.5 - 82.0

#    HorizSync	30-64         # multisync
#    HorizSync	31.5, 35.2    # multiple fixed sync frequencies
#    HorizSync	15-25, 30-50  # multiple ranges of sync frequencies

# VertRefresh is in Hz unless units are specified.
# VertRefresh may be a comma separated list of discrete values, or a
# comma separated list of ranges of values.
# NOTE: THE VALUES HERE ARE EXAMPLES ONLY.  REFER TO YOUR MONITOR'S
# USER MANUAL FOR THE CORRECT NUMBERS.

    VertRefresh 40-150

Modeline "800x600"     60     800  856  976 1040   600  637  643  666 +hsync +vsync

Modeline "1280x600"     60     1280  1336  1456 1530   600  637  643  666 +hsync +vsync

EndSection


# **********************************************************************
# Graphics device section
# **********************************************************************

# Any number of graphics device sections may be present

# Standard VGA Device:

Section "Device"
    Identifier	"Standard VGA"
    VendorName	"Unknown"
    BoardName	"Unknown"

# The chipset line is optional in most cases.  It can be used to override
# the driver's chipset detection, and should not normally be specified.

#    Chipset	"generic"

# The Driver line must be present.  When using run-time loadable driver
# modules, this line instructs the server to load the specified driver
# module.  Even when not using loadable driver modules, this line
# indicates which driver should interpret the information in this section.

    Driver     "vga"
# The BusID line is used to specify which of possibly multiple devices
# this section is intended for.  When this line isn't present, a device
# section can only match up with the primary video device.  For PCI
# devices a line like the following could be used.  This line should not
# normally be included unless there is more than one video device
# intalled.

#    BusID      "PCI:0:10:0"

#    VideoRam	256

#    Clocks	25.2 28.3

EndSection

# Device configured by xf86config:

Section "Device"
    Identifier  "foo"
    Driver      "savage"
    Option	"ShadowFB" "on"
    Option	"ForceInit" "on"
#   Option	"NoAccel" "on"
    Option	"UseBIOS" "off"
	# unsupported card
    #VideoRam    4096
    # Insert Clocks lines here if appropriate
EndSection


# **********************************************************************
# Screen sections
# **********************************************************************

# Any number of screen sections may be present.  Each describes
# the configuration of a single screen.  A single specific screen section
# may be specified from the X server command line with the "-screen"
# option.
Section "Screen"
    Identifier  "Screen 1"
    Device      "foo"
    Monitor     "libretto"
    DefaultDepth 24

    Subsection "Display"
        Depth       8
        Modes       "1280x600" "800x600" "640x480"
        ViewPort    0 0
    EndSubsection
    Subsection "Display"
        Depth       16
        Modes       "1280x600" "800x600" "640x480"
        ViewPort    0 0
    EndSubsection
    Subsection "Display"
        Depth       24
        Modes       "1280x600" "800x600" "640x480"
#        Modes       "800x600" "640x480"
        ViewPort    0 0
    EndSubsection
EndSection

# **********************************************************************
# ServerLayout sections.
# **********************************************************************

# Any number of ServerLayout sections may be present.  Each describes
# the way multiple screens are organised.  A specific ServerLayout
# section may be specified from the X server command line with the
# "-layout" option.  In the absence of this, the first section is used.
# When now ServerLayout section is present, the first Screen section
# is used alone.

Section "ServerLayout"

# The Identifier line must be present
    Identifier  "Simple Layout"

# Each Screen line specifies a Screen section name, and optionally
# the relative position of other screens.  The four names after
# primary screen name are the screens to the top, bottom, left and right
# of the primary screen.  In this example, screen 2 is located to the
# right of screen 1.

    Screen "Screen 1"

# Each InputDevice line specifies an InputDevice section name and
# optionally some options to specify the way the device is to be
# used.  Those options include "CorePointer", "CoreKeyboard" and
# "SendCoreEvents".

    InputDevice "Mouse1" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"

EndSection