On Wed, 27 Oct 2021, Haines Brown wrote:

>
>Ludovic, thanks for the feedback. The Z590 chipset is new (March
>2021), but I did see that someone had installed linux on it and so
>assumed it could be done. I don't see Gigabyte's specification of the
>video chip.
>
>The lspci command returns
>

>  VGA compatible controller: Intel ... Device 4c8a (rev 04)
>    (prog-if 00 [VGA controller])

>

I don't care about the model of your motherboard, that's not really relevant.
Actually, no motherboard is very relevant anymore. You need to care about the
chips installed on them: iGPU/GPU/CPU. We still don't have that information, and
we still don't know if your hardware is properly supported by the kernel,
firmware and drivers available from debian.

If your chip isn't yet supported by the kernel (which is doubtful for intel),
it'll fallback to known standards that every manufacturer should support. If
your display driver shows VESA, that's what I'm talking about. Since the kernel
shipped by debian is usually old, check the backports and see if that version
will help you.

>
>The non-free and contrib were already specified in my sources.list. I had
>not installed firmware-linux but doing so made no diference.
>

Too bad.

>
>You imply it would do me no good to get and install a video card.
>That came as a surprise. I had assumed that it was the card is that
>made the dpi modes accessible.
>

If there is something being displayed on your screen, you then have something
capable of computing graphics. I have no clue about the configuration of your
hardware, what's installed, what's available or not available. I don't know if
you have a GPU or if you don't.

What is made available to you are both your screen capability and your graphic
card. The graphic card will do it's best do compute an image, and that's kind of
all it does. There needs a synchronicity between the GPU and the screen polling
rate.

Your monitor carries an EDID (Extended Display Identification Data) which has
all the necessary information for the source (Xorg and co.) how to compute
compatible modes. If that can't be read or understood properly, you'll have a
limited display support or nothing at all. The software running on your computer
will then be able to tell the GPU how and when to generate an image.

I you want to know more about how to display an image on a screen, I invite you
to watch Ben Eater's instructive videos:

* https://www.youtube.com/watch?v=2iURr3NBprc&t=498s
* https://www.youtube.com/watch?v=BUTHtNrpwiI