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For the unaware, this quadrascan drew vector graphics by aiming the electron gun only where lines needed to be. This meant most of the screen wasn't illuminate

For the unaware, this quadrascan drew vector graphics by aiming the electron gun only where lines needed to be. This meant most of the screen wasn't illuminated most of the time (think LCD vs OLED). This is why long exposures like this are possible and super interesting.

pmarreck 3y ago
Are you sure? I see scan lines (of the NTSC/PAL variety) when I zoom in. I also don’t see how this scheme would be less possible with NTSC/PAL. That’s disappointing, but understandable. It would need to be original cabinet hardware to be THAT cool. EDIT: Ah, duh, in order to produce color it necessitates differently colored phosphors and a shadow mask, which might explain what I'm seeing. It does look like horizontal vector scan lines though, if you look at the screenshot I provided in other comments
- aquova 3y ago
  > Are you sure? I see scan lines (of the NTSC/PAL variety) when I zoom in. The electron gun is still having to hit discrete pixels on the screen. Rather than drawing the image line by line, it's traveling at angles to render the image. It wasn't so much that these graphics couldn't be done with the NTSC/PAL standard (although you would have an increased backlight), but it was a limitation of game hardware of the time. Defining a series of points to draw lines between required less memory than sprite-based graphics.
  - pmarreck 3y ago
    Everyone's linking me to the vector graphics data but I know- Gen X here- I know that actual vector hardware would draw the actual lines and not leave horizontal scan lines visible. This looks like a photo of an emulator. See? https://imgur.com/a/PwWpRg7 https://imgur.com/a/PwWpRg7
    - deleted 3y ago
      [deleted]
- anentropic 3y ago
  https://www.youtube.com/watch?v=smStEPSRKBs https://www.youtube.com/watch?v=smStEPSRKBs https://en.wikipedia.org/wiki/Vector_monitor https://en.wikipedia.org/wiki/Vector_monitor
  - pmarreck 3y ago
    I know what that is. The scan lines I see are horizontal. An actual vector monitor would NOT leave horizontal scan lines as it would ACTUALLY be drawing the ACTUAL image (and not a rasterized version of it) I'm not sure why everyone's jumping to (unnecessarily) correct me instead of actually zooming in on, say, the 2nd photo to see what I'm referring to. Here, let me try to screenshot: https://imgur.com/a/PwWpRg7 https://imgur.com/a/PwWpRg7 Do you not see the horizontal scan lines here? A vector monitor has free reign over the beam's direction and would then not need to rasterize EDIT: Ah, duh, in order to produce color it necessitates differently colored phosphors and a shadow mask, which might explain what I'm seeing. I was presuming single color vector display and no shadow mask, which is of course incongruous with the fact that Tempest is full-color.
    - Tempest1981 3y ago
      Perhaps the CRT shadow mask? And RGB phosphors? https://en.wikipedia.org/wiki/Shadow_mask https://en.wikipedia.org/wiki/Shadow_mask
      - pmarreck 3y ago
        Oh. You're right. Appropriate username btw!
    - Luc 3y ago
      What you're seeing are not 'scan lines'. This pattern is typical for a color vector monitor and is visible on real hardware (source: I own a Tempest arcade machine). On a monochrome vector monitor, like an oscilloscope or Asteroids, there is one electron beam that draws on the single-phosphor screen, without obstructions between the beam and the screen, leaving sharp lines. There are no pixels as such (though the hardware in arcade games may be limited to moving the beam to discrete locations), the glass is just covered with a smooth layer of phosphor. On a color vector monitor however there are three beams, and the screen has an RGB pattern of color sub-pixels. In between the electron guns and the screen is a 'shadow mask'. This is basically a plate with holes, positioned such that the 'blue' beam can only hit the blue subpixels, and likewise for the other colors. What you see in the pictures is the result of the beams sweeping over that mask and interacting with the small dots of colored phosphor on the glass. The CRT of a color vector game is just a standard television CRT. The electronics are very different however.
- nwallin 3y ago
  > I see scan lines (of the NTSC/PAL variety) when I zoom in. Color vector monitors still have discrete phosphors. You're not seeing discrete scanlines, you're seeing discrete lines of phosphors. > I also don’t see how this scheme would be less possible with NTSC/PAL. Vector drawn video games must necessarily be on an all black background. Video games that draw backgrounds and sprites typically illuminate the entire screen. Your character will move around on a colored background. It wouldn't make any sense to do a long exposure on an illuminated background; it would just be a picture of the background with some blurriness where the sprites occasionally were.
  - CmdrKrool 3y ago
    Here are a few long exposures of sprite-based games I just happened to have lying around: https://imgur.com/a/zmWL1bX https://imgur.com/a/zmWL1bX (Not sure why Imgur is gating that with an adult content warning, but I assure you all it contains nothing of the sort.)
    - mrguyorama 3y ago
      Those worked way better than I would have expected.

pmarreck 3y ago

Are you sure? I see scan lines (of the NTSC/PAL variety) when I zoom in. I also don’t see how this scheme would be less possible with NTSC/PAL. That’s disappointing, but understandable. It would need to be original cabinet hardware to be THAT cool. EDIT: Ah, duh, in order to produce color it necessitates differently colored phosphors and a shadow mask, which might explain what I'm seeing. It does look like horizontal vector scan lines though, if you look at the screenshot I provided in other comments

aquova 3y ago
> Are you sure? I see scan lines (of the NTSC/PAL variety) when I zoom in. The electron gun is still having to hit discrete pixels on the screen. Rather than drawing the image line by line, it's traveling at angles to render the image. It wasn't so much that these graphics couldn't be done with the NTSC/PAL standard (although you would have an increased backlight), but it was a limitation of game hardware of the time. Defining a series of points to draw lines between required less memory than sprite-based graphics.
- pmarreck 3y ago
  Everyone's linking me to the vector graphics data but I know- Gen X here- I know that actual vector hardware would draw the actual lines and not leave horizontal scan lines visible. This looks like a photo of an emulator. See? https://imgur.com/a/PwWpRg7 https://imgur.com/a/PwWpRg7
  - deleted 3y ago
    [deleted]
anentropic 3y ago
https://www.youtube.com/watch?v=smStEPSRKBs https://www.youtube.com/watch?v=smStEPSRKBs https://en.wikipedia.org/wiki/Vector_monitor https://en.wikipedia.org/wiki/Vector_monitor
- pmarreck 3y ago
  I know what that is. The scan lines I see are horizontal. An actual vector monitor would NOT leave horizontal scan lines as it would ACTUALLY be drawing the ACTUAL image (and not a rasterized version of it) I'm not sure why everyone's jumping to (unnecessarily) correct me instead of actually zooming in on, say, the 2nd photo to see what I'm referring to. Here, let me try to screenshot: https://imgur.com/a/PwWpRg7 https://imgur.com/a/PwWpRg7 Do you not see the horizontal scan lines here? A vector monitor has free reign over the beam's direction and would then not need to rasterize EDIT: Ah, duh, in order to produce color it necessitates differently colored phosphors and a shadow mask, which might explain what I'm seeing. I was presuming single color vector display and no shadow mask, which is of course incongruous with the fact that Tempest is full-color.
  - Tempest1981 3y ago
    Perhaps the CRT shadow mask? And RGB phosphors? https://en.wikipedia.org/wiki/Shadow_mask https://en.wikipedia.org/wiki/Shadow_mask
    - pmarreck 3y ago
      Oh. You're right. Appropriate username btw!
  - Luc 3y ago
    What you're seeing are not 'scan lines'. This pattern is typical for a color vector monitor and is visible on real hardware (source: I own a Tempest arcade machine). On a monochrome vector monitor, like an oscilloscope or Asteroids, there is one electron beam that draws on the single-phosphor screen, without obstructions between the beam and the screen, leaving sharp lines. There are no pixels as such (though the hardware in arcade games may be limited to moving the beam to discrete locations), the glass is just covered with a smooth layer of phosphor. On a color vector monitor however there are three beams, and the screen has an RGB pattern of color sub-pixels. In between the electron guns and the screen is a 'shadow mask'. This is basically a plate with holes, positioned such that the 'blue' beam can only hit the blue subpixels, and likewise for the other colors. What you see in the pictures is the result of the beams sweeping over that mask and interacting with the small dots of colored phosphor on the glass. The CRT of a color vector game is just a standard television CRT. The electronics are very different however.
nwallin 3y ago
> I see scan lines (of the NTSC/PAL variety) when I zoom in. Color vector monitors still have discrete phosphors. You're not seeing discrete scanlines, you're seeing discrete lines of phosphors. > I also don’t see how this scheme would be less possible with NTSC/PAL. Vector drawn video games must necessarily be on an all black background. Video games that draw backgrounds and sprites typically illuminate the entire screen. Your character will move around on a colored background. It wouldn't make any sense to do a long exposure on an illuminated background; it would just be a picture of the background with some blurriness where the sprites occasionally were.
- CmdrKrool 3y ago
  Here are a few long exposures of sprite-based games I just happened to have lying around: https://imgur.com/a/zmWL1bX https://imgur.com/a/zmWL1bX (Not sure why Imgur is gating that with an adult content warning, but I assure you all it contains nothing of the sort.)
  - mrguyorama 3y ago
    Those worked way better than I would have expected.