HD and Retro ...

[h8b1llg8ts]

I have two questions I want to ask back to back and want to thank you in advance for any help you could provide.

I just finished my first gameroom with is all modern gaming with a LCD, surround sound, ect. My next project is to work on my second game room with will be all retro. I'm going to use my old 42" CRT, storage, the works. But I'm also thinking ahead about my light gun games of 'ol also. Within a couple more years my CRT isn't going to work anymore and those old tubes are going to be hard to come by. I don't want to go with that Top Gun system because I like the feel of my Super Scope 6 ... really!

My first question to you is do you know if either an old projector system will work or how about the new HD projectors?

And secondly, I am running a Philips 42" 1080p LCD for all my current systems. And for now I am running my Saturn and Dreamcast of the same LCD using RCA. Is the upgrade to S-Video for either systems really going to make that much of a differance. And for those who are running VGA, for your Dreamcast, my TV doesn't have a VGA option available.

[MrPopo]

Light guns are very hit and miss on projectors. If you really want to keep using the light guns you will need to keep a CRT TV on hand (a 60 Hz one). As for the video cables, I feel it makes the Saturn look better. I use VGA for my Dreamcast, so I can't compare that. That's really weird that your LCD doesn't have a VGA port, though.

[crux]

I'm not sure what you're asking about projectors. Will they work with Cathode Ray light guns? The answer's right in the name - CRT. It COULD work with a CRT projector, but don't expect great results. I imagine someone will fill the gap when CRTs are impossible to find. Niche markets are niche markets.

S-Video will always be an improvement over RCA. The question is to what degree. There are two predominant problems with HDTVs and any system from previous generations (PS2 and older, with the exception of Dreamcast with VGA). The first issue is that upscaling low resolutions presents all kinds of ugliness on older consoles. 480i systems will see less severe issues (Saturn and Dreamcast with S-Video fit the bill), but even then it isn't ideal. The bigger problem, perhaps less noticeable for some, is the lag introduced with upscaling. The further a resolution is from the native resolution of the television, the more input lag will be introduced. If your television has a "gaming mode," that can help, but otherwise the only solution is a product like XRGB-2+, which will display the systems in a higher resolution.

Essentially, for ideal performance, any older systems should be played on the older television. Gamecube and Xbox (and Dreamcast with VGA) can output 480p, but anything older is 240p or 480i in the vast majority of cases.

[h8b1llg8ts]

I'm mostly talking about either an old projector system from the 80's. You know the old red, green, blue system or even better the new HD projector systems. I'm thinking those old systems should work because that's what Nintendo started off with when they introduced skeet shooting (remember the arcade in Karate Kid). I mostly want to use it for the NES Zapper and Guncom 2 PS1 games.

[lordofduct]

I'm not going into detail, general basic stuff is kinda answered.

Try searching the forum first next time. This is a highly spoken about topic with tons of information. I've personally gone into lengthy explanations of SEVERAL of the issues that come out of playing older consoles on newer televisions.

Oh and crux, devices like the XRGB still introduce lag because they do the SAME exact thing that your TV is doing by upscaling them. It's performance in reducing lag only depends on the quality of the upscaler in your television.

Personally I use a Marantz receiver with a high quality video processor in it to perform all my scaling and timing issues. Very little lag has been introduced into my games using it. When playing something like Radiant Silvergun directly hooked to my TV or passed through my Receiver and outputted from it over HDMI... your really can tell a HUGE difference in speed.

[racketboy]

LoD also wrote a nice guide that I'm getting ready to publish soon on the whole Retro/Home Theatre thing
Stay tuned

[DeckardBR]

How old are the CRT televisions? Any crt built in the 90s or 2000s should work for many years. I bought a sony crt in 1994 and just replaced it last year, but it was still going strong.

[lordofduct]

I'm mostly talking about either an old projector system from the 80's. You know the old red, green, blue system or even better the new HD projector systems. I'm thinking those old systems should work because that's what Nintendo started off with when they introduced skeet shooting (remember the arcade in Karate Kid). I mostly want to use it for the NES Zapper and Guncom 2 PS1 games.

Oh, you want to know about light guns... that's a very big issue to deal with.

Now the NES gun will probably work on a projector because of the mechanics behind it. But not all light guns will work as different light guns utilize different methods.


A quick review:

A) first lightgun design ever... model used by the NES zapper - This method basically has a switch that sends a signal to the game (i.e. pulling the trigger). When this is done the screen flashes to all black with coloured blocks where each target is located. The game then asks the gun to open its view scope (the barrel) and figure out the colour it is looking at (usually only black or white). It then responds with the answer and the game knows if a target was hit or not. This only supports a couple of targets at a time... more colours supports more targets but isn't as accurate.

You can tell if this is the type of design you are using by sticking the light gun up to a lightbulb and pulling the trigger. If you do this you "should" hit a target no matter what over and over. (the colour produced by the light bulb really plays a role in how well this will work).

You may also notice if you watch carefully in a game like Duck Hunt that when you pull the trigger the game flashes very bright. This isn't a "special effect" to create some feeling of interactivity. NO, instead it is actually a required part in the process of making the gun work. Of course the creative designers take the nuisances that engineers inject into their designs and turn them into "features".

You know... the ol' programmer dogma, "That's not a bug... that's a feature!"

These kinds will work on projectors and HDTVS. The only problems that can be introduced is the "time delay" created in upscaling. But if you have a fast upscaler or your TV is CRT and doesn't need to perform upscaling, then these light guns will work just fine.

B) As light guns progressed over time they needed support for more accurate targeting systems and a lot more targets on screen. One method was the hsync method.

On a CRT screen each horizontal line is drawn left to right, from top to bottom, one by one. This happens about 60 times per second on NTSC displays (hence 60hz) or 50 times a second on PAL tvs (50hz). Now what happens is a very tricky little thing.

The trigger is pulled an a pulse is sent to the game saying it was pulled.

The game then injects a high contrast point at the end of the hsync line. Most consoles supported this come the 16-bit era. This results in a line that moves vertically down the screen over 1/60th of a second... and in between each line draw horizontally across the screen. It's hard to describe with out a picture.

Anyways once the draw starts it sends a signal back to the gun to open its light sensor and watch the screen until it sees this high contrast point. The amount of time that passes along with the speed of the hsync results in a value representing the number pixels that passed. Then with a simple division and modulus of this number:

row = floor( value / horResolution )
column = value % horResolution

Now we have a cartesian coordinate representing the position the gun is looking at "approximately". And it can then compare this two the logical information describing the scene and know if you hit a target and what target that is... kinda like a mouse pointer.

This method suffers a LOT with upscaling and on projection screens. Two reasons:

upscaling puts in a delay... this delay means that the gun doesn't ever see the point. It registers as if you pointed the gun off screen. In most games pulling the trigger will always register as "reload gun".

upscaling stretches pixels... sometimes you scale to a different aspect ratio which introduces distortion. If no delay occured, you'll still register an innacurate point unrelated to where it actually was caused by the stretching (wide screen introduces this the most).

projection displays have this same stretching issue as they have to be "adjusted". If you finally tune your projector you may avoid it, but it's a LOT of work. Hopefully your game has one of the "tuner" apps built in (it usually has you shoot the 4 corners and the center of the screen), this will really help.

projection displays usually don't have the contrast ratio that allows the fun to recognize this effect panned across the sync. And of course the projection screen HAS to be a CRT projector (the old school red blue green lights). You'll usually need ALL the lights out and the light bulb fresh and bright.

CRT is a requirement. LCD and Plasma are fixed pixel distribution displays. It doesn't have a vsync. Each pixel is updated independently by the display controller. CRT has these sync lines because the CRT draws with one individual beam. It "scans" horizontally and vertically across the screen quickly changing it's frequency each step of the way. The frequency of the charge put on the chemical on the end of the bulb makes each red green and blue spec of chemical brighten up to a certain intensity quickly and for a very short moment. LCD and Plasma does NOTHING like this.

As you can tell... this type of light gun has the biggest issues. It is also the most common light gun used through out the 90's to present day.

C) IR tracing... only recently implemented in home consoles. Most notable is the Wii.

This method doesn't use the TV at all. It instead utilizes an IR pulsator on top of the television and a IR receiver in the controller... this is unique in that it works the opposite of other IR devices. Instead of the controller creating IR pulses, the display creates the pulses and the controller registers them. The thing is there needs to be a way to transmit these results back to the device... this is why it is only used on more recent consoles with the advent of wireless technologies that Nintendo and Microsoft have created that utilize things like "Bluetooth" and other frequency based wireless technologies.

How it works is basically the IR pulsator on top of the TV constantly creates a beam of multiple IR beams across the room. Basically mapping out this invisible plane across the room. (This is why you can actually replace the light bar from the Wii with candles and it still works... just not as well). The controller then watches this beam and figures out the angle at which the beam enters the IR receiver on the end of it. By "configuring" it the first time you use the console, it can use basic trig to figure out a cartesian coordinate on the screen.

Because it no longer uses the TV it bypasses ALL issues created by the TV.

Now problems that arrive here. You have to configure it for each TV as you the player still utilize the TV as your register point and your movements are in respect to it. The thing is the algorithm now depends on this configuration. Things like your play position now play a big role.

This means that if say you configure it at 6 feet from the TV, but then play the game at 12 feet from the TV, then error is introduced and it won't properly recognize your movements as accurately. This is why when you play the Wii in games like shooters it doesn't feel very accurate.

of course the Wii attempts to compensate for this as it is common for people to move around. And they use error correction algorithms to attempt to make it more accurate... but it isn't the most effective.

The design is most effective for "motion" sensing, and less for point accuracy.

[lordofduct]

not as quick as I was hoping... but eh, whatever.

LoD also wrote a nice guide that I'm getting ready to publish soon on the whole Retro/Home Theatre thing
Stay tuned

Oh... I don't remember this article. Maybe I should make an adendum to it that includes light guns as well.



[edit]
To any of the new members out there reading this.

HI! I'm LoD. I write LONG posts all the time. You might want to get used to it. I've been absent from the forums for a couple months for business reasons. Big programming job I had to dedicate a lot of time too.

But I'm back. So I hope you're ready to deal with my horrible grammar and technical expertise.


[edit 2]

Oh I just wanted to add, both methods A and B introduce another issue (more prevelent in method B). When playing multi-player error can occur if the guns are fired simultaneousily. Thankfully seeing as the amount of time allocated is 1/60th of a second, the chances of you firing at the same exact time is extremely slim. But if you have ever been in a fast fire shoot off with a mate, you may have noticed not all your shots registered.

[racketboy]

Do you want me to send it back to you for review?
I've been procrastinating on it for so long -- I keep thinking of tweaks to it.
I made a cool little table for which console support different connections and such.
Ok... so I'm getting off topic