NES games don't fill the entire CRT screen? (left side)

[pvt_awol]

Hey guys, I could do a bit more testing on my end, but I'm at work right now and I thought I'd ask instead of going through all of the trouble. I tried to google this, but I'm not having any luck.


Does anyone know if the horizontal lines of resolution are cut depending on which model of the NES you use? Or how the video is hooked to the TV? Or even, what type of TV you have?

I have a decent Sharp X-Flat 27" 4:3 CRT that I use for retro gaming, and when I hook up my top load NES with coax (sadly, I don't have the composite AV type) the games seem like they don't have enough horizontal lines for the entire screen. It's always the left side that has no game elements. It doesn't seem like anything is pushed or missing off of the right side either, I feel like I can still see everything that I'm supposed to. It's hard to explain without pics, but try to imagine Punch Out with the life bars and the ropes around the ring, ending about 1/2" to 1" from the left side of the screen. But the actual canvas colors stretch all the way out. Does that make sense? It's like the foreground game assets don't stretch all the way across, and I've noticed this on EVERY game.

I don't notice this with any other systems. Is this just what to expect from a flat screen TV with the older NES games? Am I right on the money in thinking that NES games don't have as many lines of horizontal resolution as say, SNES or Genesis?

Just something to discuss I suppose.

[Hobie-wan]

Different signals and resolutions are, well, different. Because of this a CRT might display a certain signal a little further over in one direction or a little wider or skinnier. You might adjust the width and placement when you have the NES running, but it would also affect anythign else hooked up to that same input. If you played PC games in the 90s, you'd get this a lot too if you went from a text screen, to a 320x240, to a 640x480 game. They'd all be moved around a bit and so you had to adjust as best you could to maximize all of them unless you played with the adjustment all the time.

The other thing is the NES video can do slightly different things depending on the mapper that was used and if the screen simply scrolled, or if there was a HUD that stayed put while other stuff moved. If you play a NES on a CRT and have squeezed the picture in, you can sometimes see garbage off the edge of the screen that you normally wouldn't see. There might be backgound that continues off the edge a bit, but sprites don't go into that portion as they go off the screen. You might see garbage blocks that change into their proper panels or vice versa.

[CRTGAMER]

There are potentiometers in the back of the TV that can adjust the horizontal and vertical size. A compromise of all the signals, so verify with the cable box and DVD player as well. On newer models you have to pull the cover, be careful of the HIGH VOLTAGE around the tube and flyback transformer.

[MrPopo]

Back in the day you also had a phenomena called overscan. Essentially old TVs didn't actually display as much of the picture as the broadcast resolution supported, but it varied between manufacturers. So older consoles intentionally limited themselves to the area that they were guaranteed to be visible in.

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

[pvt_awol]

^

All great info guys. I especially like the overscan stuff, and I hadn't thought of that.

I need to do more testing I think. My LD player and other consoles that hook up through composite cabling don't have this effect, only the NES using coax right now. I'm going to try a coax'd Genesis tonight, and see if it suffers the same. Perhaps it is only the input that has the issue.

I wonder, if I adjust the screen using the pots, does it affect it for all inputs? My guess is that since it's a mechanical adjustment, it would.

[Hobie-wan]

Yes, it will affect all inputs. Since the Genesis outputs a different resolution than the NES, the image will be aligned differently. If the TV setting is way off and shoved to the right, you might see something but is is possible it might look fine. In the 90s with PCs on CRTs, going from DOS to a 320 to a 640 game could shift the image around half an inch sometimes on larger monitors.

[MrPopo]

Honestly you're probably better off just accepting it as it is. I get a similar effect when I pipe my inputs through my X-RGB3; it aligns the output in the upper right corner of the active area. There might a way to adjust it but I don't feel like fiddling with the Japanese menus any more than I already have.

[pvt_awol]

I wonder if this was a much less "non-issue" with rounded TV sets, as the area I'm now seeing would have been "hidden" by the curve, or even the screen bezel.

[MrPopo]

That's precisely it.

[Anapan]

Using the service menus of Sanyo, Sony, and Toshiba CRTs I've owned I've been able to find happy mediums for various consoles using the geometry adjustments. Some NES games use an insane ammount of Overscan (it's expected to be cut off by the edges of the screen, and/or the bezel) and it shows garbage but as newer devices (DVD players, etc) came out they started using the overscan area to get more detail out of the inferior connections used in CRTs. Newer CRTs started including the overscan as part of their regular picture so the DVD picture wasn't cut-off with their factory default settings.

I use PS2 and Nintendo as calibration refrences. I load a PS2 game with screen adjustments in it's options menu to show the entire (small for a console) picture, then swap the video out for NES, and pop in Super Mario Bros to see how much more it uses. I then try to make the PS2 picture a little smaller than the cutoff for the picture so the PS2 picture isn't noticably letterboxed or showing too-much black. If you're just using the screen for NES you can include the entire picture perfectly, but several games will have garbage or preloaded tiles from the other edge of the picture in that overscan area.

If you list your CRT's model number (on a tag on the back) I can get you the command codes on the remote to allow you to adjust the geometry if it's possible on your screen. I can usually find a proper PDF service manual too. You'll be able to adjust the width, height, and picture placement at the least, probably much more as well.