[ltp] Using the T40 with video projectors?

Richard Neill linux-thinkpad@linux-thinkpad.org
Wed, 16 Jul 2003 05:27:48 +0100


Hello,

I've had this problem on my A22p (which is 1600x1200). It's exactly as 
you describe. What I think is happening is that, for any given 
resolution, the internal LCD and the external projector require 
different timing signals. If the external screen is a high-quality 
(expensive) CRT, it will adapt fine, otherwise, you get timing errors 
causing it to lose sync in various weird ways.

I find that if I Fn-F7 cycle until there is ONLY the external projector, 
it will then work OK. (Of course, you don't get the benefit of having an 
autocue though).
There's more of what I did  here (although nothing special).
http://www.richard.neill.hemscott.net/a22p-mdk9-1.html#x

Incidentally, xrandr is very useful for changing resolution - it behaves 
differently to xvidtune --next, because it actually shrinks the root 
window, rather than giving a viewport onto it, hence a presentation in 
"fullscreen mode" works sanely.

I hope this is useful as a workaround; sorry it's not a full solution.

Regards

Richard


Theodore Ts'o wrote:
> Hi all,
> 
> I wonder if any of you with T40p's (or other Thinkpads that have a
> 1400x1050 resolution displays) have run into this particular problem.
> The issue, of course, is that the projectors can't deal with the extra
> resolution.
> 
> The problem, though is that even when I bring the resolution down to
> 1024x768, or even 800x600, the projector is still not able to sync with
> the video.  It only shows part of the screen (generally the left 30% of
> the screen in 1024x768 mode is simply not shown by the video projector).
> 
> Has anyone seen this, and come up with a workaround?  I've enclosed the
> XFree86 config file which I use to try to force my T40p into 1024x768
> mode....
> 
> 					- Ted
> 
> # XF86Config-4 (XFree86 server configuration file) generated by Dexconf, the
> # Debian X Configuration tool, using values from the debconf database.
> #
> 
> Section "ServerLayout"
> 	Identifier	"T40 Layout"
> 	Screen		"T40 Screen"
> 	InputDevice	"Generic Keyboard"
> 	InputDevice	"Configured Mouse"
> 	InputDevice	"Generic Mouse"
> EndSection
> 
> Section "ServerLayout"
> 	Identifier	"T21 Layout"
> 	Screen		"T21 Screen"
> 	InputDevice	"Generic Keyboard"
> 	InputDevice	"Configured Mouse"
> 	InputDevice	"Generic Mouse"
> EndSection
> 
> Section "ServerLayout"
> 	Identifier	"X20 Layout"
> 	Screen		"X20 Screen"
> 	InputDevice	"Generic Keyboard"
> 	InputDevice	"Configured Mouse"
> 	InputDevice	"Generic Mouse"
> EndSection
> 
> Section "Files"
> 	FontPath	"unix/:7100"			# local font server
> 	# if the local font server has problems, we can fall back on these
> 	FontPath	"/usr/lib/X11/fonts/misc"
> 	FontPath	"/usr/lib/X11/fonts/cyrillic"
> 	FontPath	"/usr/lib/X11/fonts/100dpi/:unscaled"
> 	FontPath	"/usr/lib/X11/fonts/75dpi/:unscaled"
> 	FontPath	"/usr/lib/X11/fonts/Type1"
> 	FontPath	"/usr/lib/X11/fonts/Speedo"
> 	FontPath	"/usr/lib/X11/fonts/100dpi"
> 	FontPath	"/usr/lib/X11/fonts/75dpi"
> 	ModulePath	"/usr/local/xf43/lib/modules"
> EndSection
> 
> Section "ServerFlags"
> EndSection
> 
> Section "Module"
> 	Load	"ddc"
> 	Load	"GLcore"
> 	Load	"dbe"
> 	Load	"dri"
> 	Load	"extmod"
> 	Load	"glx"
> 	Load	"pex5"
> 	Load	"record"
> 	Load	"xie"
> 	Load	"bitmap"
> 	Load	"freetype"
> 	Load	"speedo"
> 	Load	"type1"
> 	Load	"vbe"
> 	Load	"int10"
> EndSection
> 
> Section "InputDevice"
> 	Identifier	"Generic Keyboard"
> 	Driver		"keyboard"
> 	Option		"CoreKeyboard"
> 	Option		"XkbRules"	"xfree86"
> 	Option		"XkbModel"	"pc101"
> 	Option		"XkbLayout"	"us"
> EndSection
> 
> Section "InputDevice"
> 	Identifier	"Configured Mouse"
> 	Driver		"mouse"
> 	Option		"CorePointer"
> 	Option		"Device"		"/dev/psaux"
> 	Option		"Protocol"		"PS/2"
> 	Option		"Emulate3Buttons"	"true"
> 	Option		"ZAxisMapping"		"4 5"
> EndSection
> 
> Section "InputDevice"
> 	Identifier	"Generic Mouse"
> 	Driver		"mouse"
> 	Option		"SendCoreEvents"	"true"
> 	Option		"Device"		"/dev/input/mice"
> 	Option		"Protocol"		"ImPS/2"
> 	Option		"Emulate3Buttons"	"true"
> 	Option		"ZAxisMapping"		"4 5"
> EndSection
> 
> Section "Device"
> 	Identifier	"S3 Inc. 86C270-294 Savage/IX-/MV"
> 	Driver		"savage"
> 	VideoRam	8196
> EndSection
> 
> Section "Device"
> 	### Available Driver options are:-
>         Option      "accel"
>         #Option     "crt_screen"
>         #Option     "composite_sync"
>         #Option     "linear"
>         #Option     "mmio_cache"
>         #Option     "probe_clocks"
>         #Option     "reference_clock"
>         #Option     "shadow_fb"
> 	Identifier  "ATI Rage Mobility"
> 	Driver      "ati"
> 	VendorName  "ATI"
> 	BoardName   "Mach64 LM"
> 	ChipSet     "ati"
> 	ChipId      0x4c4d
> 	ChipRev     0x64
> 	BusID       "PCI:1:0:0"
> EndSection
> 
> Section "Device"
> 	Identifier	"ATI Radeon Mobility 9000"
> 	Driver		"radeon"
> 	VideoRam	65536
> EndSection
> 
> Section "Monitor"
> 	Identifier	"IBM ThinkPad LCD"
> 	HorizSync	30-57
> 	VertRefresh	43-72
> 	Option		"DPMS"
> EndSection
> 
> Section "Screen"
> 	Identifier	"X20 Screen"
> 	Device		"ATI Rage Mobility"
> 	Monitor		"IBM ThinkPad LCD"
> 	DefaultDepth	24
> 	SubSection "Display"
> 		Depth		1
> 		Modes		"1024x768" "800x600" "640x480"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		4
> 		Modes		"1024x768" "800x600" "640x480"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		8
> 		Modes		"1024x768" "800x600" "640x480"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		15
> 		Modes		"1024x768" "800x600" "640x480"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		16
> 		Modes		"1024x768" "800x600" "640x480"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		24
> 		Modes		"1024x768" "800x600" "640x480"
> 	EndSubSection
> EndSection
> 
> Section "Screen"
> 	Identifier	"T21 Screen"
> 	Device		"S3 Inc. 86C270-294 Savage/IX-/MV"
> 	Monitor		"IBM ThinkPad LCD"
> 	DefaultDepth	16
> 	SubSection "Display"
> 		Depth		1
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		4
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		8
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		15
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		16
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		24
> 		Modes		"1024x768"
> 	EndSubSection
> EndSection
> 
> Section "Screen"
> 	Identifier	"T40 Screen"
> 	Device		"ATI Radeon Mobility 9000"
> 	Monitor		"IBM ThinkPad LCD"
> 	DefaultDepth	16
> 	SubSection "Display"
> 		Depth		1
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		4
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		8
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		15
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		16
> 		Modes		"1024x768"
> 	EndSubSection
> 	SubSection "Display"
> 		Depth		24
> 		Modes		"1024x768"
> 	EndSubSection
> EndSection
> 
> 
> Section "DRI"
> 	Mode	0666
> EndSection
> 
> # end of XF86Config

-- 
rn214@hermes.cam.ac.uk  **  http://www.richardneill.org
Richard Neill, Trinity College, Cambridge, CB21TQ, U.K.