CRTs and EDID (was: Re: [gentoo-user] Anybody want to beta test Gentoo with mdev instead of udev?

CRTs and EDID (was: Re: [gentoo-user] Anybody want to beta test Gentoo with mdev instead of udev?

[Michael Mol]

On Tue, Nov 15, 2011 at 1:21 AM,  <waltdnes@waltdnes.org> wrote:
> Contrary to the FUD I've heard, X works just fine, thank you, without an
> xorg.conf.  Modern flatscreens with EDID info are set up automatically.  I
> suppose that old CRT monitors without EDID info might require xorg.conf,
> but that's "exotic hardware" nowadays.

Just an FYI, EDID blocks have been part of CRT tech since the mid to
late 90s; it's the basis of "plug & play" monitors.

IIRC, the EDID block is transported via DDC, which is essentially I2C
implemented on top of your VGA cable. I've got three EDID-supporting,
19" 1600x1200 CRTs staring me in the face right now.

https://plus.google.com/108080062547354628132/posts/ZLLw66eL4We

-- 
:wq

Re: CRTs and EDID (was: Re: [gentoo-user] Anybody want to beta test Gentoo with mdev instead of udev?

[waltdnes]

On Tue, Nov 15, 2011 at 09:53:47AM -0500, Michael Mol wrote

> Just an FYI, EDID blocks have been part of CRT tech since the mid to
> late 90s; it's the basis of "plug & play" monitors.
> 
> IIRC, the EDID block is transported via DDC, which is essentially I2C
> implemented on top of your VGA cable. I've got three EDID-supporting,
> 19" 1600x1200 CRTs staring me in the face right now.
> 
> https://plus.google.com/108080062547354628132/posts/ZLLw66eL4We

  Maybe X has learned how to read them without udev's help.  The xorg
logfile shows the EDID block, max/min horizontal/vertical scan rates,
supported modes, etc.

-- 
Walter Dnes <waltdnes@waltdnes.org>

Re: CRTs and EDID (was: Re: [gentoo-user] Anybody want to beta test Gentoo with mdev instead of udev?

[Michael Mol]

On 11/16/2011 06:20 PM, waltdnes@waltdnes.org wrote:
> On Tue, Nov 15, 2011 at 09:53:47AM -0500, Michael Mol wrote
>
>> Just an FYI, EDID blocks have been part of CRT tech since the mid to
>> late 90s; it's the basis of "plug & play" monitors.
>>
>> IIRC, the EDID block is transported via DDC, which is essentially I2C
>> implemented on top of your VGA cable. I've got three EDID-supporting,
>> 19" 1600x1200 CRTs staring me in the face right now.
>>
>> https://plus.google.com/108080062547354628132/posts/ZLLw66eL4We
>   Maybe X has learned how to read them without udev's help.  The xorg
> logfile shows the EDID block, max/min horizontal/vertical scan rates,
> supported modes, etc.
>
Xorg's been around since 2004, and udev since 2003, so it's possible
that it's depended on udev for displays.

It seems unlikely, though; I remember XFree86 4.x having EDID support,
just prior to people migrating over to Xorg. It was a royal pain,
actually; my Thinkpad 760XL's LVDA (I think it was LVDA. It wasn't a
common laptop video connection yet) display didn't support EDID, and I
never did manage to get any version of XFree86 newer than 3.3.6 working
on it.

Point is, Xorg autoconfiguration has worked find for *most* setups for
almost a decade. At the very least, it's worked fine since the first
graphical Knoppix and Ubuntu live CDs.