Subject: Re: problems with X configuration
To: Wolfgang S. Rupprecht <wolfgang+gnus20050105T125146@dailyplanet.dontspam.wsrcc.com>
From: Steven M. Bellovin <firstname.lastname@example.org>
Date: 01/05/2005 18:36:12
In message <email@example.com>, "Wolfgang S. Rupprecht
>Steven M. Bellovin writes:
>> Yes, it has 1600x1200 resolution; it's a 20.1" display.
>> ... sku=320-1578
>I just love the marketing phrase "up to XXX" and a long list of
>resolutions. LCD's have one and only one pixel pitch. The fact that
>they list all those other resolutions leaves me wondering which one is
>real and which ones are interpolated.
>> What I don't understand is the phrae "Supported Future Video Modes".
>> Does that mean that VESA is considering the mode, but hasn't endorsed
>> it yet? And what, if anything, in the X suite should know about it?
>My two CRT monitors here both run in the resolutions mentioned in the
>"future modes". I don't think the "future" tag in and of itself is
>the kiss of death.
>(II) MGA(0): Manufacturer's mask: 0
>(II) MGA(0): Supported Future Video Modes:
>(II) MGA(0): #0: hsize: 640 vsize 480 refresh: 85 vid: 22833
>(II) MGA(0): #1: hsize: 800 vsize 600 refresh: 85 vid: 22853
>(II) MGA(0): #2: hsize: 1024 vsize 768 refresh: 85 vid: 22881
>(II) MGA(0): #3: hsize: 1280 vsize 1024 refresh: 85 vid: 39297
>(II) MGA(0): #4: hsize: 1600 vsize 1200 refresh: 75 vid: 20393
>What I needed to do at one point was widen the default V and H clock
>ranges (after hunting them down in the manufacturer's manuals). After
>that X had no qualms about using the future modes. The reluctance was
>simply caused by it not wanting to exceed the compiled-in default H
>and V frequency ranges.
> Section "Monitor"
> # Sony 20seII
> HorizSync 30-96
> VertRefresh 48-160
> # # hitachi Superscan Supreme 803
> # HorizSync 31-115
> # VertRefresh 50-160
>And yes, I agree X really needs to do better automating this. One
>shouldn't have to become an XF86Config file expert just to get X
>working correctly. Luckily Xorg does a much better job of
>autoconfig-ing things (it even managed to squeeze a few more pixels
>out of my Hitachi monitor, cranking it up to 1920x1440.)
I haven't found any detailed manual; the Dell web page says that this
monitor can handle "Max Sync Rate (V x H): 76 Hz x 80 kHz". X
recognized that. (Another page gives the minimum and maximum for those
values; again, X found them properly.) The X log says
"Not using mode "1600x1200" (no mode of this name)"
Where does it get the table of modes?
Poking through the X source, I see a file etc/vesamodes which
does list 1600x1200 @60 Hz, with hsync of 75 Khz. That's certainly
compatible with what the log file already knew about the monitor.
(Btw, that file refers to VESA standards from 1998 -- hardly new!)
There's another file xf86cfg/vidmode.c that lists a table modes; that
mode is listed there, too. So I don't understand where the problem is
coming from... Is the problem the vesa driver? If so, why, given that
this is an old VESA mode.
I said earlier that X confused me. That's part of it -- more, I think,
is that graphics hardware confuses me terribly. I understand some of
the physical realities of scans on CRTs and an analog cable. I would
think that LCD monitors with DVI cables could behave more -- well,
"rationally" is the word I'd use, from my perspective as a software
X has made a lot of progress; 4.4.0 is much easier to configure than
older releases. Most of the last few systems I've built have just
worked, without the arcana that used to be necessary. But I never know
when I'm going to run into something like this... (When I configured
the system, I worried about the SATA controller and the Ethernet
controller. I thought that X with an ATI controller would just
It sounds like what I should try is (a) the ModeLine that Christos
suggested, but with 162 for that first magic number, and then (b) try
Xorg. (Query: if i do use xorg, do I need to rebuild anything in
pkgsrc? Why is X11_TYPE=xorg necessary?)
--Prof. Steven M. Bellovin, http://www.cs.columbia.edu/~smb