Why Doesn't The Game Display Just Fill The Screen?

[Ronin]

I have been using a Sony BVM-20F1U for retro gaming for a while now. The picture is great, especially using RGB. However, the one thing that I find strange is that the game screen does not automatically fit to the size of the monitor screen. I have to manually adjust the geometry and because each game system has a different screen size, I have to readjust the geometry every time I change systems. Even then, I can never get the display to fit the screen "perfectly".

This isn't really a big deal. I can get the screen good enough and I have the alignment numbers for each game system written down, so changing systems doesn't take long. I am just curious if anyone knows why it is this way?

Back in Ye Olde 1990's, I played games on CRTs, as everyone did. Every game I played automatically fit the TV screen perfectly, regardless of what game system I was playing. I never had to adjust the geometry. This is the same way it works with my current generation systems connected to my modern TV. No screen adjustments necessary.

So what is the deal with my BVM? Maybe it is because it is a broadcast monitor and not a commercial CRT. I doubt it as anything to do with using RGB. Does anyone know?

[kamiboy]

Back in the day the games certainly did not automatically fill the screen perfectly. You just wasn't paying attention as a wee lad, as wee lads are wont to do.

[austin532]

The reason why every game fit the screen on a CRT TV is because of overscan which usually cuts off a good 10%-15% of the image. I would not recommend changing the screen size each time because not only is every system different, every game can have a different screen size as well.

Use the 240p test suite grid pattern to fill the screen. I would not worry about if a game does not fill the entire screen because it's not harming anything. Where as if you fill the screen with one game you might be cutting off the image on another. Make sense?

[Lawfer]

The only SD console who's gamescreen fill the whole screen is the Original Xbox.

All PS2, PS1, GameCube, Wii games I have tried had some kind of underscan resulting in the games not filling the screen.

[ZellSF]

https://en.wikipedia.org/wiki/Overscan

In case you didn't know what it was and just wanted to read a basic overview. Games probably don't render outside the safe area out of performance concerns (why render what many people can't even see).

[accaris]

Super Mario Bros. 3 is one of the worst. Nintendo must have expected consumers to play that game on nearly every TV imaginable; that's the only reason I can think of for such massive and overbearing overscan compensation.

[Lawfer]

Super Mario Bros. 3 is one of the worst.

Which? The NTSC or PAL version?

PAL games have the most underscan.

[mikejmoffitt]

I recommend calibrating to the 240p test suite, and cut off about 1/4 of one square (a 16x16 block) on each side for generally good compatibility.

[gray117]

The only SD console who's gamescreen fill the whole screen is the Original Xbox.

All PS2, PS1, GameCube, Wii games I have tried had some kind of underscan resulting in the games not filling the screen.

...Games probably don't render outside the safe area out of performance concerns (why render what many people can't even see).

... game has nothing to do with overscan? It's just how the screen is set. Many games (+tv shows/dvd menus etc etc) compensate with anything between 5<->12% border between image edge and important info [e.g. ui, brand, logo etc.].

If a particular console appears to 'fill' a screen better it's just because it's combination of frequencies and resolution are a good match for your screen's settings/mechanics.

To the OP - your childhood perception or memory is playing tricks on you - it's always been like this with crts - some just hide it better than others - think of it more like focusing camera/binoculars/zeroing a scope etc. with different users/eyes/distances : the awkward analogue world

[austin532]

I hear it's best to overscan the image by about 10% on CRT TV's to hide any kind of flaws or voltage irregularities.

[Ikaruga11]

I hear it's best to overscan the image by about 10% on CRT TV's to hide any kind of flaws or voltage irregularities.

But then you're stretching the image.

[bobrocks95]

I hear it's best to overscan the image by about 10% on CRT TV's to hide any kind of flaws or voltage irregularities.

But then you're stretching the image.

You can overscan by the same amount on all sides and aspect ratio is preserved.

[austin532]

Yeah, I think 10% sounds like a bit much. 5% sounds about right. I highly doubt CRT's came out of the box with zero overscan.

[Einzelherz]

I recommend calibrating to the 240p test suite, and cut off about 1/4 of one square (a 16x16 block) on each side for generally good compatibility.

This is a good start, but due to timing differences (iirc), each system will put the screen in a slightly different place. You might have to tweak it a little more afterwards.

[austin532]

I've wondered about this as well. Do any of the test suites output a perfectly center image? The Xbox is the only system I can think of that's closest but there is no test suite for that yet.

[Taiyaki]

I think Ronin is talking about something else here folks. It's true that with my pro monitors each console had different phase requirements to fit the screen. This is why the BVM is so good in that respect as you can map a horizontal phase setting for each channel and set them up for each console one at a time to make things easier. Some consoles require varying amounts of adjustments to actually have a centered picture. I had no such trouble with consumer sets ever, one geometrical setup was good to get all consoles centered without much more than 0~2% overscan.

[Ronin]

Thanks for all of the feedback everyone!

I guess as a wee lad I wasn't aware of overscan, so maybe I am remembering things wrong, however, I think I used the wrong words when I talked about fitting the screen "perfectly". Part of what I am talking about is what Taiyaki brought up in that different systems have different phase requirements. Although sometimes it seemed like the vertical and horizontal sizes were different too (looking at it again, I may be wrong about that).

Another thing I am refering to is the border around the screen. I wouldn't mind it so much if it was just a black border, but with some games the outer areas of the display change based on the level. For example, Super Mario Bros. has a sky blue color surrounding it on overworld levels. Sonic The Hedgehog has the sky blue border as well as some pixelization on the very bottom of the border. I guess these are things that were always there, but I just never saw it back in the day due to overscan. It really isn't a big deal. It doesn't ruin the games for me. I was just wondering why it is the way it is.

I did take some pictures in case I did not describe what I am talking about very well. The lighting isn't very good, but you can see what I am talking about. Notice that Super Mario World doesn't have the sky blue borders that SMB and Sonic have. So I guess it isn't every game.

Super Mario Bros.- http://imageshack.com/a/img924/2479/HE68V7.jpg
Super Mario World- http://imageshack.com/a/img921/4720/yFdXE3.jpg
Sonic The Hedgehog- http://imageshack.com/a/img924/3070/F3KTSq.jpg

Also, pardon my ignorance, but can someone explain the 240p Test Suite to me. I have heard about it, but have never actually used one. Thanks!

[ZellSF]

The only SD console who's gamescreen fill the whole screen is the Original Xbox.

All PS2, PS1, GameCube, Wii games I have tried had some kind of underscan resulting in the games not filling the screen.

...Games probably don't render outside the safe area out of performance concerns (why render what many people can't even see).

... game has nothing to do with overscan? It's just how the screen is set. Many games (+tv shows/dvd menus etc etc) compensate with anything between 5<->12% border between image edge and important info [e.g. ui, brand, logo etc.].

If a particular console appears to 'fill' a screen better it's just because it's combination of frequencies and resolution are a good match for your screen's settings/mechanics.

Did you somehow not understand what I wrote? I realize what overscan is and games likely chose not to render outside the safe area out of performance concerns.

TV and movies will actually have content outside the safe area (just not important content) because it does not cost them anything to have that content there.

It does cost video game consoles something to render more things on the screen.

Yeah, I think 10% sounds like a bit much. 5% sounds about right. I highly doubt CRT's came out of the box with zero overscan.

10% is right if you want no borders in almost all games. It's what I settled on as a standard and adjusting from there if there's something I can't see / if there still are any borders.

I think you'll find 5% is inadequate to get rid of borders a lot of the time.

[gray117]

Did you somehow not understand what I wrote? I realize what overscan is and games likely chose not to render outside the safe area out of performance concerns.

Nope I understand, I don't know of any games offhand which don't extend to the full frame; after all the the whole idea is create the illusion of a clean edge. It's just that critical components like, say, health bars are typically positioned within a [guessed at] safeframe, with the game rendering beyond/around them.

[Einzelherz]

I've wondered about this as well. Do any of the test suites output a perfectly center image? The Xbox is the only system I can think of that's closest but there is no test suite for that yet.

Essentially you're asking which system sends the most centered image. I think this is hard to answer since everyone's adjustments are different.

I'd say adjust with whichever suite you have access to and then throw games up from each system to tweak slightly until you're happy.

[ZellSF]

Did you somehow not understand what I wrote? I realize what overscan is and games likely chose not to render outside the safe area out of performance concerns.

Nope I understand, I don't know of any games offhand which don't extend to the full frame; after all the the whole idea is create the illusion of a clean edge. It's just that critical components like, say, health bars are typically positioned within a [guessed at] safeframe, with the game rendering beyond/around them.

Most old games render black, or colored bars around the image. Which is what this topic is about. It's really only the HD consoles that stopped doing that.

[Lawfer]

I've wondered about this as well. Do any of the test suites output a perfectly center image? The Xbox is the only system I can think of that's closest but there is no test suite for that yet.

Essentially you're asking which system sends the most centered image.

Original Xbox.

At least the NTSC Xbox through component output does.

Wii doesn't, PS2 doesn't, PS1 and Saturn definitly don't, NTSC Gamecube with Component output doesn't, FM Towns Marty doesn't.

The original Xbox is awesome like that:

- Full screen games
- 99% of games have a 480p compatibility support
- All games have in-game Dolby Digital output support
- Support both YPbPr and RGB outputs (just like the PS2)
- Best graphics out of all the 720x480 consoles
- 720p and 1080i support for a few games

Big problem with the Original Xbox is the library, because in comparison to the PS2, PS1, SNES and such it doesn't have much to offer in comparison. Well at least it has some pretty awesome titles such as this one:

https://www.youtube.com/watch?v=UW7WPn4pWEI

The only SD console who's gamescreen fill the whole screen is the Original Xbox.

All PS2, PS1, GameCube, Wii games I have tried had some kind of underscan resulting in the games not filling the screen.

...Games probably don't render outside the safe area out of performance concerns (why render what many people can't even see).

... game has nothing to do with overscan? It's just how the screen is set.

That's wrong, games have everything to do with it. Wanna know which game has the most underscan ever? Enemy Zero on Sega Saturn, the game was beautiful for it's time and as such the devs probably wanted to have the game be able to run on the Saturn, so you get a game that is 320x240 but with gigantic underscan so that the in-game screen is a small picture inside that 320x240 output.

Each game has it's own type of underscan, it is up to the developers to decide that.

[Einzelherz]

Essentially you're asking which system sends the most centered image.

Original Xbox.

At least the NTSC Xbox through component output does.

It sounds like it sends the fullest image, but not necessarily the most centered. Have you centered it and then thrown up many other systems to confirm that they orbit around it rather than all skew to one side?

[gray117]

That's wrong, games have everything to do with it. Wanna know which game has the most underscan ever? Enemy Zero on Sega Saturn, the game was beautiful for it's time and as such the devs probably wanted to have the game be able to run on the Saturn, so you get a game that is 320x240 but with gigantic underscan so that the in-game screen is a small picture inside that 320x240 output.

Each game has it's own type of underscan, it is up to the developers to decide that.

...that is not underscan... they're only updating something like a 288x144 window area within a 320×224 frame.

Of course you can render a smaller area within your full frame if you're forced to for performance reasons. They'll be some ports that retain a certain pixel aspect ratio too. But no one chooses not to fill the a frame because just possibly it might be covered by overscan. It can help if you have to, but the rationale is because either i)you have to for performance or ii)it looks better because you're sticking to a certain aspect ratio.

[ZellSF]

That's wrong, games have everything to do with it. Wanna know which game has the most underscan ever? Enemy Zero on Sega Saturn, the game was beautiful for it's time and as such the devs probably wanted to have the game be able to run on the Saturn, so you get a game that is 320x240 but with gigantic underscan so that the in-game screen is a small picture inside that 320x240 output.

Each game has it's own type of underscan, it is up to the developers to decide that.

...that is not underscan... they're only updating something like a 288x144 window area within a 320×224 frame.

Of course you can render a smaller area within your full frame if you're forced to for performance reasons. They'll be some ports that retain a certain pixel aspect ratio too. But no one chooses not to fill the a frame because just possibly it might be covered by overscan. It can help if you have to, but the rationale is because either i)you have to for performance or ii)it looks better because you're sticking to a certain aspect ratio.

They're doing it because they have to for performance and because they know it's likely (not possibly, likely) it will be covered by overscan. Those two things are related and I've yet to see any good reasoning why you think they wouldn't be.

[speedlolita]

I used the 240p test suite on my (previously owned) Duo R when I adjusted the image on my 20M4E.

Worked pretty well overall, 240p from the PS1 looked good, as did 480i from GC/PS2/Xbox.

[gray117]

There's no way in enemy zero's case it's going to be covered... it's 100% performance in cases like that.

Aesthetics. I'm not encyclopedic, but I don't honestly know a 16 bit and up game that sacrificed real estate in the direction that it scrolled [typically horizontal] - unless they were sticking to some kind of aspect ratio, or performance/design restricted to a substantially smaller window. I certainly don't believe it was common.

Letter boxing, windowed resolution sizes, and [vertical] pal conversion issues shouldn't be confused with over/underscan image synching/sizing issues... You can often get a good fit, but it's still entirely normal for a crt to struggle to be consistent over a wide range of resolutions and frequencies (which is not restricted syncing just the vertical refresh rate).

[Lawfer]

They're doing it because they have to for performance and because they know it's likely (not possibly, likely) it will be covered by overscan. Those two things are related and I've yet to see any good reasoning why you think they wouldn't be.

Indeed, anyone ever noticed that when the games switched to cutscenes, suddenly the in-game screen became smaller?

It's because usually in cutscenes, the graphics/character models became better than the graphics/characters models during gameplay and as such, they had to "sacrifice" width of the in-game screen for improved visuals.

It's the developers choice, same thing with the PSP-2000/3000/Go situation, the PSP can have full screen in the XMB, but as soon as you start a PSP game suddenly the in-game screen is a smaller vieweing areas surrounded by underscans on all sides.

[gray117]

It's the developers choice, same thing with the PSP-2000/3000/Go situation, the PSP can have full screen in the XMB, but as soon as you start a PSP game suddenly the in-game screen is a smaller vieweing areas surrounded by underscans on all sides.

... when displaying on a tv right?

I mean absolutely no offence by this, but your first language isn't English is it? I feel you're mixing up terms.

This is not over/under scan - it's a window, and/or if you like a combination of 'letter' (vertical) and 'pillar' (horizontal) boxing for performance reasons within a larger frame, and stands no chance of being covered by typical overscan - there's no way a dev thought we'd might get away with this thanks to overscan, it was just the necessary evil.

The games are rendered in their native resolution (480x272) and no scaling takes place - it is simply centered within the total 720x480 frame [presuming widescreen... 640 horizontal on 4:3..at least I presume]. This has everything to do with performance and preserving a decent looking pixel ratio, it has nothing to do with over/underscan... Otherwise closest you'd get to (assuming spare horsepower for scaling - probably not otherwise it would have been an option) would be like 1.5x, and it'd be too wide for 4:3 screen option and likely just look a bit messy especially on 2d games.

By contrast the xmb was modified to accommodate additional resolutions, as well as 4:3 and 16:9 ratios, and no doubt was only ever allocated a fraction of system resources (as opposed to games).

[ZellSF]

There's no way in enemy zero's case it's going to be covered... it's 100% performance in cases like that.

It's performance combined with the knowledge that overscan is going to compensate for a lot of the black bars. 5% of the screen being black bars is more acceptable than 15% of the screen being black bars.

Reducing rendering size for performance and overscan considerations are not 100% separate like you seem to imply.