Linux on TV
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Kernel-based DVD- and TV-Card-Support, improved graphic-card access for X-Servers and MPEG-Player with DivX-Codec. But whats the use of all this if you need to sit on your uncomfortable office-chair in front of an old 15"-Screen? |
Media convergence
is just one of many phrases used by marketing-experts to impress mortal people for we should adore them and praise things like the multimedia-refrigrator with Web-Access and webcams.
To connect a PC with a TV-set makes a lot more sense. Be it to show presentations or to watch DivX-movies.
But we shouldn't look for the posibility to read and write eMails on the TV cause he TV-screen is much too blurry.
Many companies manufacturing and distributing SetTop-Boxes for this purpose do realise that now, too.
Graphic-Card-Manufacturers already recognized this sign and provide beneath the commonly known VGS-Port an additionl TV-Out.
Unfortunately these Cards require a special driver software to reroute the output to this port. Drivers for Linux are seldom provided by the manufaturer. But it's gonna work without...
TV-Out DIY
Commonly known Linux-users are related to Gyro Gearloose and so it is not surprising that there are already some solutions for that problem. So even people owning an old graphics adapter can now be cheerful and will be able to connect their PC to the TV-Set soon...
We have to thank the X-Servers flexibility and its Modelines whithout which there would be no such solution...
For the X-Server the TV Set is nothing else than a monitor with bad resolution and a frequency of 50Hz.
The only problem is an adapter which converts between the graphic adapters VGA-out and the TVs Scart-Input
A large variety of of circuits exist to fit this purpose, the one tested by me can be found at http://www.sput.nl/hardware/tv-x.html
and looks like this:
(download EPS-File)
The Ground-lines can be connected to each other:
5,6,7,8,Shell ------------------------------------ 5,9,13,17,21
Some TV-Sets require an additional votage of 0.9 to 3 Volts connected to pin 16 to switch to the Scart-Input.
But be careful: Higher voltages could cause serious damage to the TV!
Disillusionment
As soon as the hardware is compiled we have to configure the X-Server. And this ist more problematic that compiling the hardware.
Unfortunately there is no "standard-Modeline" fitting for every X-Server using the cheapest graphics adapter ever. You have to find a special X confugartion for every hardware/software combination instead.
This adapter was primary thougt to be used with laptops to connect it to TV-Sets for showing presentations.
After testing many modelines which work with other users DIY-adapters (as they say themselves) I had to realize that none of them worked for me.
The adapter itself was compiled correctly. Connected to a PC with Voodoo3-graphics adapter the screen could be seen on TV. What a pity that the Voodoo3-card already provides a TV-out itself, so the adapter is completely useless...
Additionally you have to pay attention trying alien modelines.
Nearly everybody has already read the safety notice for the X configuration script saying "be careful, this program could destroy your Monitor!" and clicked on "continue". Normally modern Monitors turn black (not blue) if a modline cannot be displayed. In the worst case you'll get a flimmering something on the screen.
The Notebook instead, a "Toshiba Satellite 1700-400", which contains a ATI 3D Rage P/M Mobility Graphics-chipset (AGP 2x, 4MB VideoRam), shows some of the tested modelines with X
XFree86 Version 3.3.6 / X Window System (protocol Version 11, revision 0, vendor release 6300) Release Date: January 8 1999a distorted desktop. Hoping for a better chipset-support the X server was updated to
XFree86 Version 4.0 / X Window System (protocol Version 11, revision 0, vendor release 6400) Release Date: 8 March 2000The result was a pure catastrophy, because from now on - with some of the tested modelines - it was possible that the complete pc (not only the X server) commited suicide due activating the external VGA output.
Even if the TFT-display won't get any damage due this there may surely data be lost during such hangs, especially when using a 'wrong' kind of file system (Laptops shouldn't be running a journalling filesystem at all).
Modelines
If you're still reading this article you can try following modelines, which are provided by other Linux-users and named to be working correct with them - AT YOUR OWN RISK:
| Modelines |
Modeline "PAL_CCIR" 13.5 720 734 800 864 576 580 583 625 -HSync -VSync Modeline "PAL_768" 13.5 768 777 820 964 576 580 583 625 -HSync -VSync Doublescan Modeline "PAL_768" 15.0625 768 777 820 964 576 580 583 625 -HSync -VSync Doublescan Modeline "PAL_768" 15.0625 768 777 820 964 576 580 583 625 -HSync -VSync Modeline "PAL_904" 14.125 720 730 796 904 576 580 583 625 -HSync -VSync Modeline "736x575i" 14.16 736 760 824 904 575 580 585 625 interlace -hsync -vsync Modeline "640x480i" 14.16 640 712 776 904 480 532 537 625 interlace -hsync -vsync Modeline "640x480i" 14.16 640 728 792 904 480 532 537 625 interlace -hsync -vsync Modeline "736x288" 14.16 736 760 824 904 288 290 292 312 -hsync -vsync Modeline "PALi" 50.00 768 832 856 1000 576 590 595 630 Doublescan -HSync -VSync interlace Modeline "736x575i" 29.50 736 760 824 904 575 580 585 625 -HSync -VSync interlace Modeline "640x480i" 29.50 640 712 776 904 480 532 537 625 -HSync -VSync interlace Modeline "736x288" 14.40 736 760 824 904 288 290 292 312 -HSync -VSync ModeLine "TV1" 14.16 704 756 828 976 552 556 589 629 +hsync +vsync interlace Modeline "TV2" 15.00 688 790 810 960 530 560 580 625 Interlace Modeline "TV3" 15.00 688 768 800 960 516 529 537 573 Interlace Modeline "TV4" 15.00 640 728 792 960 480 509 517 573 Interlace modeline "TV5" 14.16 704 756 828 976 552 556 589 629 +hsync +vsync Interlace Modeline "TV6" 15.00 688 790 810 960 530 560 580 625 Interlace Modeline "TV7" 15.00 688 768 800 960 516 529 537 573 Interlace Modeline "TV8" 14.16 736 760 824 904 575 580 585 625 Interlace -hsync -vsync Modeline "TV9" 16.90 792 848 920 1080 532 554 559 625 -hsync -vsync interlace Modeline "TV10" 16.90 640 792 864 1080 480 532 537 625 -hsync -vsync interlace Modeline "TV11" 16.90 760 840 912 1080 480 532 537 625 -hsync -vsync interlace Modeline "TV12" 9.3 541 561 571 591 255 256 265 290 Interlace ModeLine "TV13" 15 800 856 872 952 470 490 510 525 Interlace Modeline "TV14" 14.161 690 728 792 904 271 272 288 313 +hsync +vsync Modeline "TV15" 14.16 690 728 792 904 540 544 608 625 interlace +hsync +vsync Modeline "TV16" 13.5 702 722 785 864 576 580 584 625 interlace Composite -c Modeline "TV17" 13.5 702 722 785 864 576 580 584 625 interlace -hsync -vsyn Modeline "TV18" 13.5 640 702 756 864 545 568 572 625 interlace composite |
# **********************************************************************
# Monitor section
# **********************************************************************
# Any number of monitor sections may be present
Section "Monitor"
Identifier "My Monitor"
VendorName "Unknown"
ModelName "Unknown"
[...]
Modeline "TV17" 13.5 702 722 785 864 576 580 584 625 interlace -hsync -vsyn
Modeline "TV18" 13.5 640 702 756 864 545 568 572 625 interlace composite
[...]
you can add them to the "Screen section" to choose between them using the "STRG"+"ALT" and the "+" or the "-" keys after restarting the X server (in the necessary color depth):
Section "Screen"
Driver "svga"
# Use Device "Generic VGA" for Standard VGA 320x200x256
#Device "Generic VGA"
Device "My Video Card"
Monitor "My Monitor"
[...]
Subsection "Display"
Depth 16
Modes "1280x1024" "1024x768" "800x600" "TV17" "TV18"
ViewPort 0 0
EndSubsection
[...]
It would be very useful to create a list of modelines that work with a special hardware/software combination and our TV-adapter compiled above.
working Modelines:
- Voodoo3-3000 (with TV-Out)
XFree86 Version 3.3.6
Modeline "TV18" 13.5 640 702 756 864 545 568 572 625 interlace composite
If anybody has another working hardware/software combination you should let us know (e.g. using the comment-area below this article) so we can maintain this list.
While this part of the article was dedicated to compile and configure the DIY TV-Out the second part of this article is dedicated to the configuration of graphics adapters providing a TV-Out such as the Voodoo3 or a nVidia Geforce.
to the second part...
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