Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: Ummon on August 10, 2009, 12:23:03 am
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From what I understand about how CRTs work, refresh is directly proportional to scan rate. Either one goes up or down, so does the other. In this sense, resolution is independent.
I was sorta under the impression that 15khz was a standard scan rate for monitors up until the 80s or so, and so I've often wondered how several vector games could be so much less than 60hz, for example Star Hawk: 224x256, 38hz refresh. The works out to be a scan rate of 10.34khz.
Really?
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What you know only applies to RASTER monitors, but not to VECTOR monitors.
The big difference between raster and vector screens would be that a raster monitor scans the whole screen, line by line.
A vector screen however doesn't do that. It can move the beam all over the screen in any direction.
Technically the tubes are the same. The chassis (and the yokes) are different.
Note that most vector games are black&white tubes, which have a finer dot pitch, and the got "color" with colored overlay on the screen.
Another difference would be that on a raster monitor the vertical and horizotal deflection yokes are differently, where on a vector monitor they are pretty much the same.
If I remember correctly, Asteroids for example has 10bit "resolution" on both axes resulting in 1024x1024 possible points.
The "scan rate" on a vector monitor would be measured in "points per second".
Vector monitors usually have a better contrast (by keeping the beam on the same point for some time) and look way sharper (because of the b/w tubes finer dot pitch) HOWEVER they can't show "filled" objects very good. Just think of drawing something with a pencil.
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If I remember correctly, Asteroids for example has 10bit "resolution" on both axes resulting in 1024x1024 possible points.
The "scan rate" on a vector monitor would be measured in "points per second".
I'm thinking this is the pertinent part - which is why the image is 'zoomed' in MAME when trying to run at the actual resolution - and so obviously, the calculation is different. Thank you.
Incidentally, with such high-resolution capacity, one could draw in shapes - but of course there were issues of speed and accuracy back in the day, but now? Hmmm.
PS - it comes to mind Randy actually said some of what you said above, some months ago in another thread, but if so I obviously didn't get it. Or forgot that I did. <shrugs>
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If I remember correctly, Asteroids for example has 10bit "resolution" on both axes resulting in 1024x1024 possible points.
I think it was 1024 x 768, but can't recall where I got that from (I remember because it was a reasonable SVGA resolution at the time that I read the article in question and the coincidence struck me as odd).