[Techtalk] Very basic tty question

[Akkana Peck]

David Sumbler writes:
> I have a second monitor, which is normally switched off.  (I use it
> occasionally when editing files in Lilypond, which produces printed
> musical scores.)  The resolution of the second monitor is 1280x1024
> pixels.  So it looks as if the console is using the dimensions of the
> smaller screen.
> 
> I thought I could check this by rebooting the computer with the second
> monitor disconnected.  I did this and, yes, the console filled the
> whole of the 1920x1080 pixels.
> 
> Having now reconnected the small monitor, and rebooted several times, I
> find that the coloured lines are no longer appearing on the large
> screen.  No idea why.  However sometimes after rebooting I have had the
> large screen being used in full (with the image on the small screen
> being cut off and incomplete), but other times I just get a 1280x1024
> console on both screens.  I can't figure out why it is sometimes one,
> and sometimes the other.
> 
> I need a way of telling the computer to ignore the smaller screen
> completely when formatting the console, and always to use 1920x1080. 
> How can this be done?

Sorry, I don't know. In X there are lots of things you can do with
xrandr -- I've been playing around with various ways of combining
the laptop screen and an external monitor or projector using xrandr.
But I've never tried to do that on the console. "framebuffer" is
probably the term to google for, but I don't know how much control
it offers. Possibly "mode switching" would be another helpful search
term: that's what happens during boot when the monitor suddenly goes
from VGA mode to its native mode, but I'm pretty sure there are ways
to initiate mode switching after boot. I'm seeing some possibly
useful results by googling:
  linux framebuffer OR console "change resolution" -xrandr

If you only use the second monitor occasionally, is it hard just to
leave it disconnected or turned off?

I'd guess the sometimes one, sometimes the other tells us that
monitors are like USB devices, and don't show up in any particular
order; whichever device is quickest to answer ends up being device #1.
But that's just a guess and doesn't help solve the problem.

Good luck -- sorry I don't know more about framebuffers and how they
choose their resolution, but maybe those google search terms will
help you find an answer.

        ...Akkana