3 ms·

Thats really cool. Especially completely analog. Like the original "tenis of two" circa 1960 https://en.wikipedia.org/wiki/Tennis_for_Two https://en.wikipedia

Thats really cool. Especially completely analog. Like the original "tenis of two" circa 1960 https://en.wikipedia.org/wiki/Tennis_for_Two https://en.wikipedia.org/wiki/Tennis_for_Two In a older thread about asteroids, I learned some older arcade games there were these things called XY monitors which were used by early video games (Asteroids, battle zone, starters, tempest..), which drew on the screen by moving a beam around the screen and turning on and off. Moving slower means things are brighter. Similar to an oscilloscope. https://news.ycombinator.com/item?id=13981733 https://news.ycombinator.com/item?id=13981733 There is a youtube video where someone takes a modern laser projector and recreates asteroids similar to the beam moving on the oscilloscope (Though programmed using c). https://www.youtube.com/watch?v=FkHjG759ABY&t=774s https://www.youtube.com/watch?v=FkHjG759ABY&t=774s There were some interesting links in response to my comments: including an xy monitor manual. [1] http://www.arcade-museum.com/manuals-monitors/Atari%20Monitor%20TM-146%20Issue%201%20Electrohome%20G05-801%20Monochrome%20XY.pdf http://www.arcade-museum.com/manuals-monitors/Atari%20Monito...

semi-extrinsic 10y ago
> drew on the screen by moving a beam around the screen and turning on and off Actually all CRT displays (box TVs/monitors) did this, only they move the beam in a predefined pattern (line by line downwards) and all you can do to control image is to turn the beam gradually on or off. Color uses an RGB shadow mask and three phospohors with different colors stuck together to make a pixel. But on vector displays like you mention, which were much less common, the software actually defined the beam path and you could have super-precise vector graphics. Some displays were of the storage tube type, which would glow for several minutes, so once drawn you could add more stuff to an image, but to erase you had to reset the whole screen - very similar to a Kindle display. Others had ~30fps refresh rate. Vector displays were great back when memory was so limited a 6404808 bits image was out of the question. Storing only vertices of polygons is much cheaper. But due to the poor text rendering and shading capabilities of vector displays, bitmapped CRTs took over once memory had been riding Moore's law for a while.
- problems 10y ago
  Wouldn't you expect vector text to look better? Sharper. Like going from text at 100 DPI to 300 DPI. Is it a precision issue with controlling the beam?
  - VLM 10y ago
    Linearity of the scope amplifiers was a big issue. Back when this was a thing there was a big difference in image quality between a Tektronix or HP oscope vs some no name scope. For probably 40 years people have been hooking up 8 bit microprocessors and DACs to a scope and trying to display a clock or something and getting a perfectly round clock dial with a cheap scope is not easy.
tyingq 10y ago
Trammel Hudson's blog is also a great resource for vector monitors, cool things done on oscilloscopes, etc: https://trmm.net/Category:Vector_display https://trmm.net/Category:Vector_display

semi-extrinsic 10y ago

> drew on the screen by moving a beam around the screen and turning on and off Actually all CRT displays (box TVs/monitors) did this, only they move the beam in a predefined pattern (line by line downwards) and all you can do to control image is to turn the beam gradually on or off. Color uses an RGB shadow mask and three phospohors with different colors stuck together to make a pixel. But on vector displays like you mention, which were much less common, the software actually defined the beam path and you could have super-precise vector graphics. Some displays were of the storage tube type, which would glow for several minutes, so once drawn you could add more stuff to an image, but to erase you had to reset the whole screen - very similar to a Kindle display. Others had ~30fps refresh rate. Vector displays were great back when memory was so limited a 6404808 bits image was out of the question. Storing only vertices of polygons is much cheaper. But due to the poor text rendering and shading capabilities of vector displays, bitmapped CRTs took over once memory had been riding Moore's law for a while.

problems 10y ago
Wouldn't you expect vector text to look better? Sharper. Like going from text at 100 DPI to 300 DPI. Is it a precision issue with controlling the beam?
- VLM 10y ago
  Linearity of the scope amplifiers was a big issue. Back when this was a thing there was a big difference in image quality between a Tektronix or HP oscope vs some no name scope. For probably 40 years people have been hooking up 8 bit microprocessors and DACs to a scope and trying to display a clock or something and getting a perfectly round clock dial with a cheap scope is not easy.

tyingq 10y ago

Trammel Hudson's blog is also a great resource for vector monitors, cool things done on oscilloscopes, etc: https://trmm.net/Category:Vector_display https://trmm.net/Category:Vector_display