• frezik
    link
    fedilink
    arrow-up
    1
    ·
    edit-2
    11 months ago

    It will tend to turn the beam on when it’s off to the side, outside the normal range of the screen. X Windows users in the mid 90s had to put in their exact scanline information or else the screen could blow up. That went away with a combination of multiscan monitors and monitors being able to communicate their preferred settings, but those came pretty late in the CRT era.

    Edit: in any case, color screens need to have at least bands of red/green/blue phosphor. At a minimum, there will be breaks along either the horizontal or vertical lines, if not both.

    • Aceticon@lemmy.world
      link
      fedilink
      arrow-up
      1
      ·
      11 months ago

      I remember doing that configuration for X.

      You had to tell it when to change lines, when to start firing on a new line (i.e. you changed lines then waited a bit and only after started sending data), then when to stop firing and finally another wait after which a change lines (so there was some “empty” at the start and at the end of a horizontal electron gun trace and you had to tune those so that the image didn’t start or end outside the screen).

      There was also something similar for the vertical axis - i.e. instructing it to go back to the top and some empty lines at the top and the bottom.

      I wouldn’t say it was convenient (it was a bloody text file with weird-looking numbers and you did run the risk of blowing up the CRT), but it was kinda fun that you could create your own crazy screen resolutions for X once you understood the principle of the thing.

    • grue@lemmy.world
      link
      fedilink
      English
      arrow-up
      1
      ·
      11 months ago

      When you say “blow up” do you mean the tube would literally explode, it would burn through phosphors, a circuit board would let the magic smoke out, or something else?

      I remember configuring mode lines in X. Luckily, I never found out the hard way what happened if you got it wrong.