Changing the resolution on a CRT normally doesn’t make the picture smaller. There is no native resolution, phosphors are not pixels. My Viewsonic would display 640x480 or 1600x1200 on the whole 21” regardless. You can also watch the video, it’s not using a smaller area.
I believe the limitation is bandwidth, not the electron beam.
There is a limit on the spacing of the colour bands though. If you want colours then you have to hit the spots where the correct phosphors are and this limits the usable resolution.
Yeah I didn’t think it would make the “pixels” smaller, but the beam would need to pulse less often and therefore could travel more. Maybe I’m misunderstanding what they did.
Electron beams scan insanely fast, that isn’t the limiting factor. Getting that much bandwidth across a VGA cable is tough. If you wanted super high refresh rates on old CRTs you’d have to drop the resolution. Same concept.
Yeah basically you can only signal “on-off” so many times a second in a vga cable before the ons and offs get blurry and unusable. So you can trade lower resolution for a higher frame rate as long as you keep the total number of on-offs below the limits.
It makes sense you’d be able to get a much higher refresh rate on a tube if you reduce the resolution, since you would be reducing the beam’s travel.
Changing the resolution on a CRT normally doesn’t make the picture smaller. There is no native resolution, phosphors are not pixels. My Viewsonic would display 640x480 or 1600x1200 on the whole 21” regardless. You can also watch the video, it’s not using a smaller area.
I believe the limitation is bandwidth, not the electron beam.
There is a limit on the spacing of the colour bands though. If you want colours then you have to hit the spots where the correct phosphors are and this limits the usable resolution.
What do you mean? The shadow mask ensures the gun for each colour can only hit the phosphors of that colour. How would a lower resolution change that?
Yeah I didn’t think it would make the “pixels” smaller, but the beam would need to pulse less often and therefore could travel more. Maybe I’m misunderstanding what they did.
Electron beams scan insanely fast, that isn’t the limiting factor. Getting that much bandwidth across a VGA cable is tough. If you wanted super high refresh rates on old CRTs you’d have to drop the resolution. Same concept.
Ah. I see, so reducing the resolution was more about sending frames to the monitor faster, not about optimizing the tube hardware’s behaviour
Yeah basically you can only signal “on-off” so many times a second in a vga cable before the ons and offs get blurry and unusable. So you can trade lower resolution for a higher frame rate as long as you keep the total number of on-offs below the limits.