On Sun, 20 Mar 2005, [ISO-8859-1] Bernd M�ller wrote:
I put the caveat in there because I'm in the US and haven't ever personally dealt with PAL or SCART. As far as I understand it, however, SCART basically provides the *opportunity* to drive R/G/B directly, with composite sync... so no "conversion" to YPbPr is necessary. I have built my own equivalent circuit for NTSC that encodes to S-vid and had to program the modelines accordingly. Basically, though, all the video is the same. The only potential gotcha is what the trigger voltage on the SCART connector is. If it's TTL like the monitor, you should be set. I'm not completely sure of the spec, but I see a slight bit of weirdness here:Hello;
I didn't build the cable until yet. But will do next days. Your last posting was
a little bit scarring me, as you wrote that your informations are "only" hypothetical. Up to this point i've had believed you had build this cable and are using it successfully with the G400. As i've had spent so much time in the G400 and had also build three different VGA-SCART cables, which all do not worked for me, my motivation was not so high to test an new hypothetical cable. But as Peter wrote he is using this cable, although with a simple CAT5 wire, i will now hot my soldering iron.
http://www.hut.fi/Misc/Electronics/circuits/vga2tv/circuit.html
http://eab.abime.net/showthread.php?s=&threadid=13037
I'm sure it won't take much to figure out, but there might be an "rbg enable" requirement to make it go. I just assumed that sending RGBS would make it go.
I've to solve an other problem before. I'm not eble to find any valid PAL modeline for X. I tried the following onesI've gotten that message before, too, and it pisses me off. There's a big different between a mode not working due to dotclock, vs. due to interlace. Since it definately says that it will go down to 12MHz, it'd suspect it either can't or won't do interlacing.
Modeline "768x576" 14.767 768 769 839 945 576 577 581 625 interlace -csync Modeline "768x576i" 14.75 768 784 864 944 576 582 588 625 interlace -csync Modeline "720x576" 13.875 720 744 808 888 576 582 588 625 interlace -csync
but get
(==) MGA(0): Min pixel clock is 12 MHz (==) MGA(0): Max pixel clock is 360 MHz (II) MGA(0): PAL TV: Using hsync range of 15.00-80.00 kHz (II) MGA(0): PAL TV: Using vrefresh value of 50.00 Hz (II) MGA(0): Clock range: 12.00 to 360.00 MHz (II) MGA(0): Not using mode "768x576" (bad mode clock/interlace/doublescan) (II) MGA(0): Not using mode "768x576i" (bad mode clock/interlace/doublescan) (II) MGA(0): Not using mode "720x576" (bad mode clock/interlace/doublescan)
This is a little bit confusing me, because minimal dotclock is 12 MHz. The modes should be all valid. I've i general problems to use any interlaced mode for X. If i try some non-interlaced [EMAIL PROTECTED] modes with dotclocks around 27 MHz X will accept them. But they are not interlaced. Interpreting the above error message i would say, the G400 is not able to generate PAL dotclocks around 14 MHz. But from web i know the card is capable.
You need to have HorizSync set to a minimum of 15kHz on whatever head you're planning to run the TV on. Since you've got a dual-headed, tvout, beast of a card I'm not familiar with, I suspect there could be some other weirdness preventing you from cooking up your wanted modeline. It's odd, though, since normally a bad HorizSync line makes modes not work due to "horizonal frequency out of range", not "bad mode clock/..."I'm using the latest version 4.1 of the original Matrox driver. The importend lines from my XF86Config:
Section "Device" Identifier "Device[1]" Driver "mga" EndSection
Section "Monitor" Identifier "PAL TV" HorizSync 30.0-80.0 <-----BAD! This needs to be set to 15kHz VertRefresh 15.0 Modeline "768x576" 14.767 768 769 839 945 576 577 581 625 interlace -csync Modeline "768x576i" 14.75 768 784 864 944 576 582 588 625 interlace -csync Modeline "720x576" 13.875 720 744 808 888 576 582 588 625 interlace -csync EndSection
The matroxfb support is compiled in the kernel, but X don't use the framebuffer with this configuration. So i assume it dosn't matter.*Probably*, but you never know. I've had weirdness before with X and framebuffer arguing.
At least i would like to use the G400 with this general VGA-SCART cable. The solution with the framebuffer, i'm using it until yet, is frustrating me. First i've spend much time to configure kernel, frambuffermode and X, soldering the special matrox VGA-SCART cable an now i've to notice the whole setup does not work reliable. Changing framebuffermode, setting the registers for contrast, hue ist working in general bu sometimes not. Sometimes i simply get a greyscale or distorted image. Assigning frambuffermode or contrast a seconed time leads to a good image. I don't know if the problem is in hardware or software. But i know a solution using the general VGA-SCART cable has to be more reliable and more flexible 'cause some newer grafic cards, especially the ATI Radeon 7500 and higher, are supposed to be capable to generate valid PAL/NTSC signals
That's the sort of weirdness I was talking about.
I still think that getting it to work out of normal VGA is the best option... since like you say it'll work with other things. Convincing the matrox card to be normal might be the trouble... :)
-Cory
************************************************************************* * Cory Papenfuss * * Electrical Engineering candidate Ph.D. graduate student * * Virginia Polytechnic Institute and State University * *************************************************************************
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