Main > Main Forum
New arcade vga on pc monitor pics, Not impressed at all.
RandyT:
--- Quote from: Xiaou2 on September 20, 2006, 02:31:26 pm ---
I believe I know why you see the lines and I do not.
Its because your monitor is higher resolution than mine.
In such a case... the monitor is being fed too little information to fill all its
available pixels up... so it skips every other line when drawing. This causes
the lines to be there.. and maybe more visiable than not
--- End quote ---
A CRT is an analog device. It does not have "pixels". The number of lines it produces is based on the scanning frequencies. How many you can count is based on the dot-pitch and how well the focus and convergence can be controlled.
A 15.75khz scanning monitor with a 60hz refresh will produce the same number of scanlines as any other CRT running at those specifications (IE. Standard Resolution)
--- Quote ---However, on my turbo monitor, all the pixels are lit up, as there are no extras
so there is no need to skip lines. Thereore, you do not see the black lines.
--- End quote ---
Again, no pixels. It's just a piece of material with holes in it. A fat, fuzzy out of focus electron beam will pass through far more of those holes than it should. It will also cause impurities in your color and result in overall poor definition.
--- Quote --- The black lines are not created as an effect by drawing.. but instead, because they being skipped. However, not all monitors are skipping like this. The skipping is usually done in Interlace modes only... or maybe in such a case where there isnt enought data givin to completely fill all the pixels.. as described above.
--- End quote ---
Interlace doesn't "skip" lines. Doing so would be pointless. Interlace cuts an image of higher vertical resolution than the monitor can display into 2 parts and displays it in two passes. It relies on the persistence of the phosphor to keep the previous one lit until it draws the next, which is offset, using timing, to fill the gaps between the lines of the previous image. A standard res arcade machine draws a full frame 60 times a second (with a 60hz refresh). An interlaced screen draws a full frame only 30 times a second.
Your Turbo monitor is not interlaced, it's just old and / or improperly adjusted.
--- Quote ---
Btw, there are arcade games that have Interlacing. Tekken III is one of them.
It can be turned on in the service menu. This is a late model (3d fighting)
game... and such a feature was not in the golden oldies as far as I know.
--- End quote ---
I don't consider Tekken III a classic, which is why I stated it that way. But it's not surprising. It takes more horsepower (memory. processor speed, etc) to manipulate data for interlaced operation than progressively scanned output at the same frequency. Not an issue nowadays, but it was big one in the "old days".
--- Quote --- And finally, my rather newish Panasonic TV does not have the appearence of the
scanlines either. Its limited use, and its rather new age, tell me that the guns are not
out of whack. I can upload a pic later.
--- End quote ---
Of course it doesn't. It is NTSC and NTSC is by definition an interlaced technology. It probably also has long persistence phosphor so you don't see a lot a flicker ....for TV images anyway. Check out the Windows desktop at an interlaced 640x480 and watch your brain hurt.
RandyT
NoOne=NBA=:
--- Quote from: Kremmit on September 16, 2006, 02:16:15 am ---Now if they can just get my dad to stop stretching 4:3 pics to 16:9. Everybody's head looks like Ernie from Sesame Street!
--- End quote ---
There's no "Smart Stretch" mode on his set?
Mine will allow you to stretch the screen to fit while leaving the center of the picture relatively unstretched.
The idea is that you will probably focus more on whatever is at the center of the screen, so it stretches all the "not being looked at" stuff.
patrickl:
Xiaou2, doesn't it make sense that if the electron beam is finer than the scanline spacing that you get gaps between scanlines? Which is something which might happen when a CRT is used on a low resolution. Besides, if your monitor doesn't show gaps between scanlines it doesn't mean no game will ever show these gaps.
I wonder though, can't the electron beam be made roughly as wide as the scanline? But then maybe that's something they couldn't do properly back then (giving too much overlap and/or a fuzzy look)? Or is there simply a maximum width for the beam.
BTW how does ArcadeVGA handle this?
Anyway, I think I have to upload a picture I once took of a CRT screen too :)
OK, so I took it a few months ago and it's more "artsy" than technical, but it has purdy colors :angel: It's a (full frame) picture of a windows cursor on a TV screen (100Hz Philips Matchline so no gaps between scanlines showing)