Main > Main Forum
You too can do KILLER vectors at 15khz!!
RandyT:
--- Quote ---But........that is _exactly_ what I wrote ::)
--- End quote ---
Well, not really. Even if the vector display had phosphor so light in color that it approximated the worst raster scanning CRT in the black areas, the vector display would still far outshine it in brightness in the areas where graphics were displayed. Your explanation seemed to focus on this difference between the bright and dark areas as being the primary reason for the enhanced display characteristics, when it is almost 100% due to the reasons I outlined. That is why I stated "not exactly", instead of "incorrect". Also, I could be wrong, but I highly doubt that they "slow the gun". Doing so would cause terrible flicker on everything that wasn't bright, and they were constantly battling this as more objects were placed on screen. It's far more likely that the entire screen refreshed at a constant time-base, with brighter objects simply getting more power from the gun(s). The reason brighter objects flicker less at the same refresh rate is because the long persistence phosphor ( the reason everything had a "trail") glows longer when blasted with more electrons.
--- Quote ---Quadrascan was simply the name that Atari used for XY monitors (B/W and color). Because they were writing the "four quadrants" of the screen.
--- End quote ---
Then the wiki is wrong. You should probably correct it if you know better.
--- Quote from: Wiki ---Color displays
Some vector monitors are capable of displaying multiple colors, using either a typical tri-color CRT, or two phosphor layers (so-called "penetration color").[citation needed] In these dual-layer tubes, by controlling the strength of the electron beam, electrons could be made to reach (and illuminate) either or both phosphor layers, typically producing a choice of green, orange, or red. Atari used the term Color Quadrascan to describe this colour version when used in their games.
--- End quote ---
RandyT
CheffoJeffo:
Atari used the term QuadraScan to refer to their vector monitors in general -- to my knowledge, the term QuadraScan has nothing to do with dual-layer phosphors (as evidenced by the fact that they refer to their BW vectors the same way). A quick reading of the memo to ops for the WG Color QuadraScan confirms that it uses three beams.
The particular reference that RandyT cites is WikiPedia, not the BYOAC wiki, and is written poorly enough that it seems to imply something that I don't think is true.
My understanding of the dual-layer phosphor (and I can't recall where I read about it) is that it was limited in terms of the number of colours that could be produced (which would make sense since there are only two layers, hence only two colours to blend).
RandyT:
--- Quote from: CheffoJeffo on June 11, 2009, 03:50:55 pm ---My understanding of the dual-layer phosphor (and I can't recall where I read about it) is that it was limited in terms of the number of colours that could be produced (which would make sense since there are only two layers, hence only two colours to blend).
--- End quote ---
Like I said, someone should change that Wiki if they know better. The odd thing is that this is not the only reference I found stating this while digging, so it may be a wider misconception.
Also keep in mind that this could still produce quite a few colors. The guns are analog, so a number of variations of green, yellow, orange and red could be produced with only two colors. But no blues or violets without a third color. So looking at it from that perspective, and unless Atari shifted gears somewhere, it doesn't seem likely that this is accurate.
Could be that someone just assumed it was different because of the different name and that the "quadra" came from X, Y and 2 levels of Z (Quad=4)
Ummon:
--- Quote from: RandyT on June 11, 2009, 04:10:42 pm ---Like I said, someone should change that Wiki if they know better.
--- End quote ---
That's why relative to here I say 'the wiki', but for Wikipedia say 'Wiki', no 'the'.
Navigation
[0] Message Index
[*] Previous page
Go to full version