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What the Death of CRT Display Means For Classic Arcade Machines (venturebeat.com)

An anonymous reader shares a VentureBeat report:The cathode-ray-tube technology that powered the monitors for nearly every classic arcade game in the twentieth century is defunct. Sony, Samsung, and others have left it behind for skinnier and more lucrative LCDs and plasmas, and the CRTs that are left are about to sell out. The current stock of new 29-inch CRT monitors is dwindling. Online arcade cabinet and parts supplier Dream Arcades has fewer than 30 of those large displays sitting on its shelves. When it sells out of the current inventory, it will never get another shipment in that size again. "We've secured enough [of the other sizes] to get us all the way through next year," says Michael Ware, founder of Dream Arcades. "After that, that's it." The future of arcade-cabinet restoration is looking bleak. "The old arcade games are like aging people," says Walter Day, founder of high-score-keeping site Twin Galaxies. "They have old livers and aging kidneys. There will come a day when very few arcade cabinets have original components. Time will wear them out." To be clear, it's not that games like Donkey Kong or Pac-Man will suddenly become unplayable. The games can run on newer LCD screens, but they may not look as the developers intended.

36 of 184 comments (clear)

  1. How are light gun games developed now? by damn_registrars · · Score: 5, Interesting

    This is somewhat orthogonal to the topic, but the CRT was a requisite for the home user to play light gun games on systems like the NES. However in the arcade we still see new installments of Time Crisis and others, and they are even done on wide screen monitors. This suggests to me that they have moved to LCDs, but I can't find good information on how they work if they did. Anyone know the answer?

    --
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    1. Re:How are light gun games developed now? by Anonymous Coward · · Score: 2, Informative

      NES lightgun just inserted a totally a black frame with white shapes where the target was and the gun sensed the light. At 50/60 Hz it was fast enough to not see it.

    2. Re:How are light gun games developed now? by realmolo · · Score: 3, Informative

      If they're using an LCD screen, the lightgun games work the same way as a WiiMote, basically. Just more accurate. There were a few "lightgun" games on the Wii, and that setup worked well enough.

      If the game uses a gun that is permanently mounted to the machine, then obviuosly the gun is really just a big joystick, and the screen used doesn't matter.

    3. Re:How are light gun games developed now? by GoRK · · Score: 3, Informative

      They just use some other means of referencing position such as IR LEDs + camera (like a wiimote or in reverse), image capture/analysis, gun position sensing, or some combination of these things. Most use IR LEDs. Some older technologies such as the NES Power Glove used ultrasonic positioning.

      A lot of the 2000's era arcade gun games such as Time Crisis 4 used DLP projectors from the get-go and were using these types of gun controllers from the start; so they are relatively easy to convert to LCD.

      Classic CRT based light gun games -- while I'm sure it's possible to build some sort of device that emulates the original gun in hardware, it is probably a much easier job to simply run them in an emulator.

      One saving grace to this article is that while it's true that the CRT business might be winding down, the tubes themselves do usually last far longer than the electronics and will be around for a very long time still. I have had to replace some components on my Wells Gardner CRT that I used in my scratch-built cabinet because it had gotten very dim, but after a new neck board and some new capacitors it's back to looking like new.

    4. Re:How are light gun games developed now? by tepples · · Score: 5, Interesting

      The Zapper does not work with LCDs. It uses a circuit similar to that found in infrared remote control receivers. The circuit is tuned to sense light that flickers at roughly 16 kHz, which matches the horizontal scan rate of a CRT SDTV.

      Furthermore, some NES games actually measure the time between the start of the picture and when the Zapper begins to detect light. This lets the game tell how far up or down the gun is pointed and narrow down the set of targets that it has to turn on in sequence. Operation Wolf does this, as does Zap Ruder (source).

      If you have an LCD, you need to wait until 2026 for the Wii Remote patents to expire.

    5. Re:How are light gun games developed now? by ausekilis · · Score: 2

      A little more info. If you're looking at building your own arcade cabinet with light guns, then ultimarc has the Aimtrak. I picked up a couple guns and the IR sensor bar for my cabinet, basically it's just like the WII with an IR sensor bar mounted either above or below the screen, and each gun appears as a mouse to the computer. The actually work pretty well for games like Area 51.

      Note that is for the "free-standing" guns that are tethered with a cable. Games like RevolutionX and Terminator 2 have hard-mounted guns on a swivel. Those are joysticks in disguise.

    6. Re:How are light gun games developed now? by thegarbz · · Score: 2

      But other games like Operation Wolf seemed to work on an entirely different principle.

      The principle is the same, just the method by which they got to the answer was different.

      For Duck Hunt the only thing of interest was if a duck was hit or if it was not. To do this every trigger pull caused a few frames to be rendered. Firstly a black frame for calibration, then a frame with a white box over one duck, then a frame with a white box over the second duck, etc. By timing which frame you were on you knew which duck got hit.

      Operation Wolf on a trigger would draw a black frame, followed by a white frame. The key is it timed how long between the start of the frame and the point where the gun registered light was. Based on this it knew the exact pixel that the gun was pointing at as a CRT rendered each frame line by line from side to side.

  2. I realize this is bad for 'purists' but... by Baron_Yam · · Score: 5, Interesting

    I'm not terribly troubled by it. My MAME cabinet has an LED screen in it, which means lower power requirements, a sharper image, and no real worry that the main screen will burn in.

    If the retro community is big enough, somebody will produce a 4:3 aspect ratio, slightly convex LED with a thick glass cover - and perhaps even an onboard function that can simulate burn in.

    It still won't be the same, of course, but neither are the guts of most arcade systems anyway.

    1. Re:I realize this is bad for 'purists' but... by Thyamine · · Score: 2

      I feel the same way. I have a MAME cabinet running with an old 21" monitor (78+ pounds) which at the time was great. Now it just feels antiquated and like more of a hassle to deal with when I want to move the cabinet around. I'm sure I'm not a purist enough, and this is more about original cabinets. If I had a original game, I can see being disappointed that it may be hard/impossible to get original-stye replacement parts.

      --
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    2. Re:I realize this is bad for 'purists' but... by AmiMoJo · · Score: 5, Interesting

      There are actually plenty of screens out there, just look on eBay or at your local charity shop. The problem is that arcade monitors are a bit special, typically more adjustable than a standard TV and accepting different signal levels. I expect we will start to see more and more conversion kits and signal conditioners to cope with this as supply dries up.

      A lot of supposedly dead CRTs could be fixed, if people knew how or if it made economic sense. Sounds like the point at which spending a few hundred bucks to repair a screen is almost here. It's like with VCRs - they were so cheap you might as well chuck a broken one and replace it, but now you can't buy them new and second hand ones are a crap shoot people are willing to spend money maintaining good ones.

      --
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  3. Wasn't there a "translator" made to handle this? by ctilsie242 · · Score: 3, Interesting

    I was reading that someone made a translator that could take the VGA signal from games made for CRTs, and "convert" it to display accurately on LCD monitors, where the fringing aspect (as in Apple ][s) was accurately simulated. Perhaps this might be the way to go.

  4. Vector? by drinkypoo · · Score: 2

    I don't take this problem seriously for most machines, because they can use software filters and high resolution displays to emulate the look pretty closely. But vector games will require crazy high-resolution displays to get the same effect, and those aren't cheap. I wonder if you could just bounce a laser (or simply a highly focused light) off a MEMS mirror or something. Or maybe you'd use multiples?

    I've thought about building an upright arcade machine with a good-sized pivot LCD, I've got two 25.5" and I use one on my PC and the other one is sitting around. To me, using a LCD is a massive feature because I can build the machine shallower.

    --
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    1. Re:Vector? by Khashishi · · Score: 2

      Yeah. The last time I saw an old asteroids cabinet, I was spellbound. The vector graphics were crisp and had smooth diagonal lines, and the bullets were awesomely bright with an ethereal glow that you see on old oscilloscopes. I don't think you can get that kind of brightness with an LCD.

    2. Re:Vector? by metaforest · · Score: 2

      Vector games did not have very high resolution, and did not draw pure 'analog' vectors. Go take a look at the schematic for Asteroids.... There is a pair of line drawing state machines that steer the X-Y position of the beam at a resolution of 1024. Technically, +- 512 because the DAC output is run through a buffer Amp that takes the output of the DAC and centers it around zero. The input to the DAC is treated as a 10-bit signed integer. There is a bit more magic upstream to generate the clock pulse chains that get sent to the position accumulators. They were just drawing lines. If you want the gory details you can read about them here from one of the engineers that worked at Atari on these games: http://www.jmargolin.com/vgens...

  5. I grew up with arcades in the 80s by MindPrison · · Score: 3, Interesting

    And I even had a whole bunch of the arcade machines in my home (my parents weren't terribly happy about that, they saw it as gambling machines), but nonetheless they where a lot fun to mess around with, I used so called "gender changer" plugins to change PCBs from various manufacturers to work with my arcade cabines, oh the fun times!

    That aside - I don't find the LCD panels so terrible as a replacement. I've just recently built my first own Arcade machine ever (it's mame based of course), but I built it out of the blue, no blueprints - just on the memories from the arcade halls, and it turned out fantastic. In fact, it is so good - that I don't really miss the blurry scan-lines and out of focus convergence RGB issues the old CRTs back then had.

    And, I've buried the LCD deep into the arcade so I can't really spot the difference, it's not easy to see there's not a "curved" crt inside there, and it looks amazing. I instantly felt the nostalgia when I fired it up.

    --
    What this world is coming to - is for you and me to decide.
  6. Progress/ by ledow · · Score: 2, Interesting

    I imagine pretty much the same as the death of AM/FM radio for old wireless sets, or the death of leaded petrol for old cars.

    They won't work the same, will require conversion, you'll have to keep a stock of old parts, or forever stay as an historical artifact that "doesn't work because we don't use those for that any more".

    There's nothing a decent LCD can't replicate, and only the purists care. Those people who want to remember the game will load up an emulator, which is probably infinitely more convenient to use and have in the house nowadays than a huge great expensive cabinet with parts you can't replace any more.

    Things move on. At least you *can* emulate the old games still. I'm all for emulation / preservation projects. But unless someone bothers to keep making CRTs in a variety of different sizes in an affordable manner, they've gone the way of the dodo - like Kodachrome film and Polaroid snaps.

    The only loss might be to lightgun games that use certain technologies but, to be honest, pretty much those kinds of input can be emulated in much more convenient ways too.

    1. Re:Progress/ by jwdb · · Score: 2

      There's nothing a decent LCD can't replicate, and only the purists care.

      Actually, there's at least *one* thing: true vector graphics. There's a few games out there - Asteroids comes to mind - where the game ran the CRT like a line plotter rather than like a raster printer, such that you ended up with very sharp perfectly antialiased line art. You'd need a high-DPI LCD to even approximate this.

  7. I've never really tried to service a game cabinet by King_TJ · · Score: 2

    ... but I thought I just read an article a week or two ago about a huge electronics recycler who it turns out wasn't really doing much recycling of old CRTs after all. They had warehouses chock full of old televisions and computer CRTs.

    I can see where maybe a 29" CRT is an odd size that's difficult to source. But I would think you could reuse a working CRT tube out of a television or monitor for a game cabinet in many cases?

  8. Bad TV Adjust Box? by Chordonblue · · Score: 3, Interesting

    Stella's (2600 emulator), implementation of 'Bad TV' adjusts is just amazing. It simply wasn't the same playing 2600 games with perfectly clear graphics. In fact, some of those old games COUNTED on a little bleed and fuzziness! I have mine set for RF with a little bit of drift - just like the old days with my uncle's G.E. 25" lightning-struck set.

    If you haven't seen the 'Bad TV Adjust' feature on Stella, it's worth a look - and that got me thinking (always dangerous!)...

    What if you could construct a box that would take an RGB-based analog signal, run it through the same formulas that Stella borrowed, and then output that to an LCD or OLED? That way, you could get all the scanlines and composite NTSC color drift you wanted... If it didn't delay things too much, that is.

    --
    "...Well, there's egg and bacon; egg sausage and bacon; egg and spam; egg bacon and spam; egg bacon sausage and spam..."
    1. Re:Bad TV Adjust Box? by PPH · · Score: 2

      Can this emulate a loss of horizontal sync? I miss the old days of watching scrambled porn.

      --
      Have gnu, will travel.
    2. Re:Bad TV Adjust Box? by FyRE666 · · Score: 2

      You can actually create scanlines, focus, tear blur effects etc with pixel shaders with no CPU overhead. It wouldn't be that difficult to take the framebuffer from MAME and use it as a texture to a shader to get any kind of distortion needed really. You could even make it appear as though the game is playing on a curved display.

  9. The warmth of vinyl by Overzeetop · · Score: 4, Insightful

    CRT renderings of the games was not how the designers wanted them to look, just as musical artists and engineers don't want to sound like a vinyl record. They wanted them to look like modern 4k, photorealistic games but were held back by the technology. No, what will be gone is the experience of the fuzzy-edged, low resolution games people remember playing as children. What we're losing is nostalgia, not veracity or design intent.

    --
    Is it just my observation, or are there way too many stupid people in the world?
    1. Re:The warmth of vinyl by omnichad · · Score: 2

      I agree (mostly). However, they did count on it for dithering colors with the bleed and smoothing jagged lines.

      I certainly prefer SNES graphics with nearest-neighbor scaling to hq2x and the like. There are too many errors in the added details and it's way more of a distraction than jaggies. It's worse than the 120Hz motion interpolation that was a big deal in last generation's TVs. I don't want all the downside of CRT - fuzzy edges, distortion, scanlines, etc. Back when I had a TV like that, I wanted better. Why would I want worse now?

    2. Re:The warmth of vinyl by squiggleslash · · Score: 5, Insightful

      Well, kinda. Yes, the original authors probably wanted higher quality graphics, but they designed for hardware that couldn't show those graphics, and they made use of the features of the technology available to them, some of which aren't replicated in the 'better' replacements.

      To put it another way, had better technology been available, they wouldn't have made the same design decisions, because design decisions intended to make something like awesome on a CRT can make things look worse on a better screen. Color bleed and interlacing would be two examples of things you make use of, that would make a game seem better on a CRT than not using them, but would make a game look awful if the technology is used on an LCD.

      --
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  10. What kind of mind reader is msmash? by 140Mandak262Jamuna · · Score: 2

    but they may not look as the developers intended.

    Now we know. Msmash is a time traveling mind reader. Knows what the original Donkey Kong developer intended!

    Did it occur to people that this crisper better images is probably what the developers intended to create, but unable to deliver? Yes, it is different from what I saw back in 1980. But to think the developers intentionally went out to create exactly that image, is a stretch.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  11. India's Videocon still makes CRTs / Recycling? by BUL2294 · · Score: 5, Informative

    I call bullshit. Sounds like "Dream Arcades" is trying to find out creative ways to announce that they will jack up their refurbishment prices--and their profit margins...

    1) An Indian manufacturer named "Videocon" still manufactures CRTs. So, while it's not Sony or some other high-quality manufacturer, they are still making them. In fact, as of a year ago, they were accepting leaded CRT glass for recycling into new CRT TVs. https://resource-recycling.com...
    2) There's a warehouse in Columbus, OH, which will likely become an EPA superfund site, that was run by an electronics recycler called Closed Loop--which went bankrupt. It's full of old CRTs that I can imagine could be reused with some minor disassembly & testing. https://motherboard.vice.com/e...

    --
    Windows 3.1x calc: 3.11 - 3.10 = 0.00
  12. There is hope by Oasiz · · Score: 4, Interesting

    This is a big issue with demanding gamers like those in the speedrunning community, a traditional (15KHz) CRT is a must for low latency.
    The concern for CRT loss was valid, however things are finally starting to look a bit better..

    I'll guess I will go a bit technical since I work with & troubleshoot "old system video stuff" quite often..

    What old consoles / arcade games pretty much always used was RGB input, which was virtually artifact free. Although with consoles you usually had to resort to composite/RF/svideo, RGB being more common only in EU/JP regions. NTSC/PAL artifacts also can still be included easily with an otherwise superior image, but I won't get in to that here..

    Biggest issue with flatscreens has always been that they only handle native resolution, anything else than native has to be scaled to be that specific resolution, resulting in blur and loss of image quality.
    What's even worse, older systems and games sort of hacked around the typical broadcast standards where it kept transmitting one field instead of alternating between odd/even, this gave you a stable picture of 60fps (Closer to 59.94Hz in reality) with the expense of dark lines on every other scanline and only 240 lines of vertical resolution. "Stretching" of the image happened naturally as the lines for both fields would go from top to bottom, resulting in a crisp image that was rather flicker free.
    Unfortunately almost no scaler that has been built actually respects this hack, hardwired to expect both fields, which is a 480 line image. While this works for TV broadcasts and looks quite good with such, it has very varying results with older systems as the flat panel will attempt to treat this low resolution image as something that's supposed to be higher resolution, resulting in awful scaling artifacts or the whole picture jumping/flickering.
    However there are thankfully scalers out there that do, like the micomsoft xrgb series or a pure linedoubler like the earlier xrgb or ther more recent ossc.
    With these, you can get pretty darn accurate results and can even simulate scanlines.

    While CRTs look cool, they're not all so cool to work with.. they can get dark/blurry/get color offset even after a couple years of active use on some cabs. Not saying they all do but rarely do I see a crisp image on an arcade cab crt these days. Flat panels do have their own issues but I guess what I want to say here is that It is indeed getting harder and harder to find replacements for a reasonable price, unlike flatscreens where an older 1600x1200 panel from 10 years ago can be perfect.

    Now I hate to sound like an advertisement but I highly recommend checking out the OSSC, It's a no compromise solution that does pure linedoubling, very good digitizing that keeps colors intact (along with noise filtering) and allows you to keep the original refresh rate intact, all combined are something that no scaler does. Personal results with flat panels and say.. a megadrive has given me pretty much emulator crispness on the picture and virtually zero latency (we are talking about a few scanlines as it doesn't have a framebuffer).

    Anyway, tools are there to get a superb image out of older systems, including consoles that have RGB output available.
    I wouldn't worry too much anymore as the quality you can get has already surpassed a CRT.
    Currently the main problem is the entry price, which can cost you $200 or up.
    Most likely in the future stuff like this is gonna come down in price and re-implemented & cloned for cheap in china.
    Cheap scalers that do better than the average TV do exist but I'd say that they still fall short.

  13. OLED replaces CRT nicely by funky_vibes · · Score: 2

    Forget LCD, last time I built a MAME-box it took me weeks of running around different electronics store showrooms to find that one IPS-display that happened to have good enough contrast and colour to replace an arcade-CRT.
    Also, when I inquired about the price, it cost like 3x as much as other similarly spec:ed displays.
    In the end, the colours were reasonable, but the viewing angles are still very much lacking.

    OLED has the best colours and contrast of any past or current display technology. That's what I'd hold out for when I get fed up of the blurryness and bad contrast of LCDs and want to upgrade my cabs.

  14. What it means? Nothing, but cost. by NotQuiteReal · · Score: 3, Interesting

    The answer to the question is it will cost more to get a CRT screen, since they are no longer produced on an industrial scale.

    There is no reason you can't make one.

    Maybe you can get this guy to make you a screen - he makes tubes, he just needs to think bigger...

    --
    This issue is a bit more complicated than you think.
    1. Re:What it means? Nothing, but cost. by iggymanz · · Score: 2

      hahaha, there are HUGE reasons why you can't make a modern color CRT screen, utterly beyond anything a hobbyist could ever hope to do. You should look up what is inside one and what tolerances are needed. That takes tens of millions of dollars worth of equipment.

  15. The last CRT rebuilder in the US shut down in 2010 by Ellis+D.+Tripp · · Score: 2

    , and the last one in Europe followed them in 2013.

    With the death of CRT manufacturing, the supply chain for the exotic materials and supplies needed for rebuilding has subsequently dried up.

    The Early Television Museum in Ohio has rescued some equipment from the last rebuilders, and is hoping to bring back at least a bare bones rebuilding capability, aimed initially at vintage TV collectors.

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  16. Light gun emulator by tepples · · Score: 2

    The point is though, existing CRT light-gun games will simply stop working when the CRT is replaced, and there will be no easy fix.

    An MCU that reads a Wii Remote and translates it into light gun signals is possible.

  17. A deeper look at the CRT 'look' by PhantomHarlock · · Score: 4, Interesting

    Putting on my old school broadcast engineering hat for a second. There are a lot of differences between CRTs and LCD displays, and in terms of nostalgia and authenticity towards 'the way it was' yes there will be something lost. For starters, CRT tubes were driven with an interlaced signal - the gun would scan top to bottom every other pixel row in 1/60th of a second, then scan the rows between those bottom to top in the next 1/60th of a second. Each set of half resolution rows is called a field. NTSC television ran at 60 fields per second, which gave the motion equivalent of 60 frames per second. A lot of these video games ran using only one field, for a vertical resolution of about 240 lines, at 30 fields per second. In between those lines were black lines, which gave the games a unique look. Rather than doubling each line, which makes the graphics look blocky, the black lines tricked the eyes into making it look like it was a higher resolution than it actually was, it gave a pleasing look. On some emulators such as MAME, there is an option to add the black lines in, which approximates the look. for the games that ran the full 60 fields, it also had a unique look as you could make out interlace flickering. Another artifact is the slight glow / spillover from each pixel, and the rather large visible discreet R, G and B dots that make up each pixel area, which also had some black between them. Add to that the curvature of the glass, and the frequent misalignment of the RGB pattern giving a chromatic abberation towards the edges of the signal. (when the R, G and B lines diverge) plus the softness of the analog signal overall, and you have a pretty unique look. In truth, emulators display games far crisper than they ever looked to us. This tends to over-emphasizes the simplicity of the graphics in a negative fashion. It's very possible to get close to the CRT look, but it will never be quite the same. I think that increased computing power will allow for the emulation of all of the artifacts listed above in realtime, it's just a matter of someone understanding them enough to emulate them. you could even dictate a level of screen burn for the attract screens, which most games tended to develop after a number of years cycling endlessly.

    In the mean time, get thee to an arcade expo such as California Extreme to experience it 'as it was'.

  18. I'm not worried by jgotts · · Score: 2

    I didn't have time to read all of the comments. My apologies if this is already well-tread ground.

    There are hundreds of millions of CRT television sets out there, and if you do a search on Youtube you will find videos of people who are fixing (to a degree at least) television sets that have been sitting out in the elements for decades. Television sets that have not been abused will last, essentially, forever: Even if you have no electronics troubleshooting skills, you can swap parts with other televisions until the set works. The only real wear out component in most televisions is capacitors, and you can train yourself to do cap replacements. I would imagine for really old televisions you will need to make some internal adjustments. That's not rocket science, either. Download the service manual.

    Right now people can't give CRT's away. Even thrift stores don't want them. But if for some reason the supply-demand curve swings around the other way, then people like me will start servicing CRT televisions and reselling them. If you can still buy vintage radios from the 1940's, then you can find a television set made in the 1990's. The "problem" is that manufactures can't profitably make them, and they may never do so again. Existing CRT televisions, though, won't be disappearing any time soon.

    I'm looking forward to the day that we start going to landfills to retrieve electronics for recycling, but we're a long way from that level of desperation (or technical ability).

  19. It's OK... it's not worth it. by gosand · · Score: 2

    I will preface this by saying I grew up in the 80s, arcades, and even had 5 or 6 machines and about 30 boardsets in my day. I have burnt many a finger soldering up JAMMA or customized harnesses, and used to go to game auctions. It was a great time! I had friends that resurrected long-dead games from various ROMs they collected. I have seen and played one-of-a-kind games. I remember when people in the usenet community started building multi-game boardsets, it was very very exciting.

    If you would have told me I could have a big, thin, relatively cheap monitor for a cabinet that replaced the CRT, without the downsides of screen burn, weight, or the distinct possibility of electrocution, I would have loved it. Yes, there is something about the original monitors, the smell when they get warmed up, the glow, the look, etc. But that's because that was the best we had at the time! Newer isn't always better, but in this case I believe it is.

    I sold off my cabinets and boardsets about 10 years ago, it was sad to see them go. I am so glad that I got to grow up during that time. But I have a hard time being nostalgic for the CRT.

    --

    My beliefs do not require that you agree with them.

  20. Re:Wasn't there a "translator" made to handle this by Miamicanes · · Score: 2

    The thing is, most of those old games WEREN'T 'really' 30hz... they were 60fps.

    A NTSC display could only display 30 complete frames per second, but the video chips on most legacy games didn't send complete frames... they sent 60 FIELDS per second (each of which contained ONLY the odd or even scanlines from each frame). CRT TVs were "dumb", and depended on the video signal itself to tell them whether the next field was odd or even (with one shifted vertically to fill the gaps between the other). So games simply never TOLD the CRT that a field should be shifted, allowing those 60 fields to be repeatedly drawn over the same half of the scanlines while the remaining half remained dark.

    This actually caused problems with a lot of first-gen LCD TVs. They'd buffer a field, buffer the next, then freak out when they couldn't decide which one was supposed to be "even" and which one was supposed to be "odd". The usual result was either an empty blue screen (possibly with something like "invalid signal" displayed as well), or a mangled mishmash with what were SUPPOSED to be two independent 60fps frames forcibly-interleaved into the same 60fps frame and shown twice in a row.

    In any case, even if the native framerate WERE 30fps, high-bandwidth VRAM can solve the problem for you... buffer a few scanlines, then do the effects processing in the time it takes a later scanline to do its horizontal retrace and output the whole thing through the VRAM's back door, so you're only adding a few scanlines' worth of latency instead of an entire frame's worth.