What do you use for 31-kHz gaming these days? A tiny 20'' VGA PC monitor? I hope you don't !
I use a Diamondtron (Trinitron licenced to Mistubishi) 22" PC monitor. 20.5" of visible picture (52 cm). An UNMATCHED quality, no other screen can display this resolution with such a precise and pleasant to the eye pixel, no other screen can produce this "scanline feeling", so "video games" like.
There's no way I would play 480p on fixed res flat screen (no matter LCD, plasma, DLP...). Even If I find one of those 4/3 40" 640x480 plasma (to avoid any loss of picture quality and lag due to scaling), I would not trade my little PC monitor. Even when you consider CRTs (the best technology ever for gaming :P ), I wouldn't buy a large 29" tri-sync monitor (from any type), because I know I wouldn't get such an amazing picture (because of the large pitch, and quite unprecise cathodes, focus system and yoke winding). Sure, I would still get a very nice picture (much better than any crap flat screen), but "plain" (= no "scanlines", no little black space between lines) and rather soft, with some moiré and convergence issues (which can be slightly reduced for the few tubes with a slightly smaller picth, and with a precise yoke that you will need to adjust anyway for convergence issues, because they become very annoying when you go to the limits of the tube).
So, for me, the ultimate gaming screen (only one, for every use, meaning every resolutions) doesn't exist.
You need CRT technology of course :D , but you definitely need at least two kinds of CRT:
- one for 15 Khz (and the few 24 Khz stuffs).
Easy, it exists since forever, it's the "standard resolution" tube, that can display the best 240p output in large format, direct view (29" to 40"). No other tubes can display such a large beam, with all the quality we like from the behavior of the beam (visible variations of scanlines size).
The curved Trinitron is your best friend, especially in tate, because it gives you not only the sharpest beam and precise scanlines (with nice variations of size according to colors, and still precise for the smallest spot size), but the cylindrical shape gives you an "Axelay effect" to all your vertical shooters, much more than a spherical tube (and of course a flat CRT ^^').
Playing some masterpiece like Layer Section (with lots of "3D" effects due to paralaxes and multiples sprites with their own speed for big enemies) on a finely tweaked curved Trinitron is really amazing, a quality you had never find in any arcade cab'. It's like you rediscover the game ! ^^
The old analog chassis (before 1994) are the best to provide you accurate and well balanced colors, with the least modifications of video signal, and easy geometric corrections. Digital chassis tend to have too much "enhancement" features (denaturation of the signal), and on flat CRT, it's a pain in the ass to get a good linearity (when you want perfect scrollings, something you especially want in shoot'em ups), and even difficult to adjust colors (because of design choice, every manufacturers wanted to show a model with the blues more blue than blue and reds more red than red, because the digital ships allow it easily).
But you can only find "raw deinterlacing" (as a feature in the TDA-8366 for example) in digital chassis, and until I managed to achieve a separate circuit to do it properly (or someone else do it ^^), it's the only way to do it with genuine hardware and games.
- then, if you want the best 31 kHz picture, you need CRTs that can go higher than 31 kHz. But because they can go higher, it means they can't go lower than 31 Khz (when they accept 15 kHz input, they upscal it to 31 Khz).
The easiest and cheapest way is to buy a high-end PC monitor, you can buy some for a few peanuts (<- we use this expression a lot in french, for saying "ridiculously inexpensive" ^^' ).
I have 5 big 21-22" monitors, from 1995 (curved Trinitron) to 2002 (flat Diamondtron). They all produce nice pictures, but the last one delivers an amazing display. Each lines have the same characteristics as the ones you see from a regular 29" Trinitron at 240p. It's your 31 kHz stuff with a 240p look, Trinitron quality. Something that I personnaly highly appreciate. :P But OK, it's small...
To find the same quality on a bigger display, you don't have to look over regular tri-sync monitors who are basically "simple TV tubes" (large pitch) with electronics that allow 31 Khz (and think that many large "XGA" CRTs (that are supposed to handle 1024x768) have a large picth too, meaning you can't achieve the same quality than on a smaller PC monitor (fine pitch). No, you need to find one of those early HD TV in USA (around 1999, fine pitch and 4/3 format) or expensive (even in the second-hand market) broadcast/graphist monitors. Almost none of them support 15 kHz. Because they are basically PC monitors of bigger size (and they were damn expensive when they where out, and non available to home market).
An other way is to use a tri-tube projector. You need a dedicate room to operate it if you want a decent picture, and of course you need to know how to set-up the projector. You can also make a rear-projection system with tri-tubes projector (the basic 7" ones can produce a nice 800x600 easily and are cheap nowaday), so you can use it in a daily room, but you have the typical issues of rear-projection: narrow view angles, low contrast. Never as good as a direct view tube.
So, for me, in tri-sync monitors, only the chassis are interesting. Just buy the electronics and adapt it to a good TV tube (you find it for free on the streets, or buy it in repair shops for 10-15 €). But, in arcades, there aren't any Trinitron tubes, so all the chassis are designed to run on the classic shadow mask tubes, either spherical or flat. And the difference of quality between a 240p picture on a Trinitron and on a shadow mask tube will be even stronger for 480p stuff, because a Trinitron is better to display thin spot (but you always have the large pitch issue, a 29" large pitch Trinitron can't produce the same précision as a 22" low pitch). But, hey, it's a decent quality anyway, but from everything I saw until now (in arcades and home cab' of friends), the 480p result is far from my little 22" monitor. Even worse, a 480i non filtred picture on a classic Trinitron is more precise (because the shadow mask dont' have enough space to let the beam strike the phosphore in every situations). That's why I don't want to spend several hundred € (monitor and shipping) to buy a thing that my little 30€ PC monitor will put to shame (and even the old 1995 one, found for free in the street, will produce a better 480p picture :P).
Yeah, it's not easy, you need to know exactly what you want, what is available, and your degree of exigency.