O-kay, I've read a ton and searched the forums concerning how to get the values for the "DisplaySize" setting in the XF86Config-4 file. Obviously, all of my attempts at trying to find the exact settings have not yielded anything legible (man, those fonts are hurtful in the TV Guide). And since all of the references I've found are for either a 27" TV or an HDTVMofo, none of those settings have helped. They've only confused me more than I normally am. So I'm hoping someone here can help me with the following:

DisplaySize settings for a 32" TV (I'm using an nVidia FX5200, S-Video)
Font Point Sizes used (if not using MythTV's default)
What theme is being used (I've discovered that not all theme guides are created equal)

Thanks.

I think you missed the point. The real display size doesn't matter since the trick is all about lying to the X server so it chooses a 100dpi or 75dpi font size. What really matters is the desired display resolution (640x480, 800x600, ...) and the DPI number for the font that you want to use. The numbers in my previous examples should work as is for an 800x600 display (the numbers are in millimeters, don't ask me why they used mm for the display size and dpi for the font size). Here's how to get the right "fake" numbers for 640x480 at 75 DPI:

640 pixel dots / 75 dots per inch = ~8.53 inches
8.53 inches * 25.4 millimeters per inch = ~217 millimeters

(480 / 75) * 25.4 (do we really need to show the units again?) = ~152

So you would use: DisplaySize 217 152

For 100 DPI replace the 75 above with 100, for different horizontal and vertical resolutions replace the 640 and 480, ...

Edited to correct the units and misplaced decimal point in the second example.

Aaaahhh...now I understand how it works. Being able to actually SEE the math calculation really helps. Thanks a ton tjc. I think this should really be added to the "FontSizeHowTo" on the KnoppMyth Wiki site. At least it would give the newbies (or idiots like me) a better idea on how to calculate these settings. BTW, is that a typo in the section "(480 / 75) * 2.54" since above it you're using 25.4 for the unit of multiplication? Thanks again for the help.

actually I think the 25.4 centimeters per inch is the typo.

_________________
Have a question search the forum and have a look at the KnoppMythWiki.

Xsecrets

Actually 25.4 is right since it makes the numbers work, but centimeters isn't. I should had said millimeters instead. I'll go back and fix it to prevent accidents for naive users...

Millimeters...centimeters...it's all metric.

Anyway, after some tweaking, it looks like DisplaySize 214 163 (100 DPI @ 800x600) renders readable fonts in the Guide and everywhere else. Thanks again for your help. Now it's just a matter of tweaking my nvidia-settings.

great post after a little playing i have a legible guide finally.

Thanks

OK, I get the displaysize math but...Since I set it up incorrectly to begin with, HOW DO I and WHERE DO I edit the file to make the change to keep from going blind.

See the example here: http://www.knoppmythwiki.org/index.php?page=XF86ConfigForFX5200HowTo

OK -- Here's the bonus round...

How do I affect the font and widget size of the underlying gdm window manager, so that I can actually see menus and read text on an xterm when the frontend is down?

I can see the Myth menus and such easily, but when I exit the frontend and try to use something like nvidia-settings, I can't even read the menus or text because of ny 1920x1080i display. It's gotten even harder to read with the 8174 driver.

It seems to me I need something like a 200 or 400 dpi font size for gdm!

_________________
Do you code to live, or live to code?
Search LinHES forum through Google

Well you can always try hunting down where those are invoked (look in /etc/X11/fluxbox/ and /home/mythtv/.fluxbox/) and add appropriate -font or -fn setting to the command lines...

I'd like to set my display correctly.
But I read somewhere that I can destroy my TV if I enter wrong values.

I understood the math calculation.
But Am I compelled to use a 800x600 resolution? NTSC is 720x480 isn't it?
How do I know if I shoud use 100 DPI or 75 DPI?
For now I'm in 800x600 but xterm is unreadable , the GUI is too large and TV is not square. (it's round on the EDGE).

My TV is 27". I'm using S-video.

Please don't hijack threads like this. The topic of this thread is how to determine the correct pseudo DisplaySize to force the use of 75 or 100 DPI fonts, not how get a good/safe X configuration for TV output.

The critcal factors for getting a safe TV out mode are the HorizSync and VertRefresh rates. These are completely independant of the DisplaySize setting. If you want to discuss this further please start another thread or follow up on one where this is already being discussed.

tjc, I apologize.
I mixed DisplaySize and Refresh rates.
I though this topic was near to my questions, that's why I posted here. I didn't want to post a redundant topic.

Sorry about that.