Re: any pages listing text mode resolutions of video cards?

["Daniel B." <dsb@smart.net>]

Jochen Schulz wrote:
> Daniel B.:
> > Kevin,
> >
> > > And setting vga=771 or similar in your kernel options?
> > Yes.  I've been using vga=10 in my kernel options (via LILO) to set
> > the virtual console text mode resolution at boot time.
>
> I am not absolutely sure, but I don't think vga=10 gives you a real
> framebuffer. 

Right, it does not.  That's what I have been using up until now,
to select a video card hardware text mode (instead of selecting a
kernel framebuffer mode using video card hardware graphics mode
(assuming I understand things right)).

> It just changes the font, which may result in more
> characters on your display. 

Actually, it doesn't change the font (or just change the font);
it does change frequencies and the total number of pixels available
for the hardware to use to display text.


...

> vga=771 (and similar values) on the other hand really switches display
> resolution (and color depth) and is most certainly what you want.

Yeah, I'm trying that range of numbers and framebuffers now.



Hey, a related problem is that in graphics mode, the X server won't
use any mode where the dot clock is higher than 125 MHz, even though
the video card goes to 230MhZ.

(I made a 125MHz mode line and it worked; I changed it to 126 MHz and
the server excluded it, and it's not excluded because of horizontal
or vertical frequencies outside the monitor's range.)

/usr/share/doc/xserver-xfree86/README.ati.gz says

  ... maximum allowed clock frequency ... 3D Rage adapters.  For
  now, clocks will, by default, be limited to 80MHz, 135MHz, 170MHz,
  200MHz or 230MHz, depending on the specific controller.  This
  limit can only be increased (up to a driver-calculated absolute
  maximum) through the DACSpeed specification in XF86Config.

That doesn't quite match up:  The driver (or server) seems to have
a limit at 125 MHz, not any mentioned in that read-me file.

Anyway, I tried the "DacSpeed xxx" option in XF86Config-4 to set
tell the server and driver the limit, but it doesn't seem to have
any effect.

In fact, when I tried "DacSpeed 114", it did _not_ prevent use of a
mode with a dot clock of 125 Mhz.  It's like it's getting ignored
entirely.


My X server is Sarge's xserver-xfree86 4.3.0.xxx.
The server's driver is the "ati" driver.
The video card is an ATI Radeon Rage XL 8MB PCI card.


Thanks,
Daniel
--
Daniel B.
dsb@smart.net