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Atari 2600 Resolution - A 'Straight' Answer...


Trebor

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Please pardon my ignorance or/and stupidity, but could someone please tell me the max display resolution of an NTSC Atari 2600?

 

For instance:

 

Atari 5200: 320x192

Atari 7800: 320x200(some claim 320x240)

ColecoVision: 256x192

 

Atari 2600: From what I've read and trying to comprehend - 48x192 or 160x262. I know this is probably inaccurate. Could someone *please* tell me what is the acutal numbers?

 

Thanks.

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The sprites' pixels, if stretched across the entire width of the 2600's potential output, would be 160 pixels horizontal. The playfield limits you to 40 pixels, however.

 

The vertical is a different story. For NTSC you can draw to any scanline you want up to the point where it goes off into overscan. So that's about 200 pixels or so.

 

However, we recently discovered that the 2600 can also generate an interlaced display like a regular broadcast signal. Therefore it can really draw 400+ pixels vertically, although there probably isn't much you can do productively with that extra resolution, given the added flicker of interlace and the wide horizontal pixels and all.

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The sprites' pixels, if stretched across the entire width of the 2600's potential output, would be 160 pixels horizontal.

The word "would" is very important here, because in practice you can only use 48 of the 160 pixels (except when you want to repeat the same pattern again and again). That's the usual resolution of e.g. six digit score displays or hires title graphics.

 

The recommened vertical resolution of a NTSC game is 192 lines, but many (esp. later) games display a few more lines.

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However, we recently discovered that the 2600 can also generate an interlaced display like a regular broadcast signal.  Therefore it can really draw 400+ pixels vertically, although there probably isn't much you can do productively with that extra resolution, given the added flicker of interlace and the wide horizontal pixels and all.

 

Are you sure there's absolutely not a single game-concept that would benefit from this technique?

 

Mabe it could be used for a scrolling background for a shootemup?

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Please pardon my ignorance or/and stupidity, but could someone please tell me the max display resolution of an NTSC Atari 2600?

 

[snip]

 

Atari 2600:  From what I've read and trying to comprehend - 48x192 or 160x262.  I know this is probably inaccurate.  Could someone *please* tell me what is the acutal numbers?

 

Thanks.

 

 

Background graphics resolution is 40 pixels across. Vertical resolution is standardised at 262 pixels, of which some 200 or so lines may be used for graphics display. It's up to the programmer, but not all TVs will fit larger numbers of lines on the visible display area. Recent developments have extended the display resolution to 525 pixels INTERLACED (that is, 262.5 lines over 2 frames, each frame offset by half a line). Sprites missiles and ball have a finer horizontal pixel resolution (160 pixels), but these are limited in number and usage.

 

So the "straight answer" is that "it depends".

 

Theoretical resolution: 160 x 525.

Practical resolution: 40 x 262, with some sprites over that.

 

In short, the best actual image you will be able to display, full-screen, is roughly 40 pixels across by 400 lines deep (interlaced). Using sprites gives you better resolution but much less screen coverage.

 

As you see, there's no simple "straight" answer at all!

 

Cheers

A

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Are you sure there's absolutely not a single game-concept that would benefit from this technique?

 

Mabe it could be used for a scrolling background for a shootemup?

There might be, but don't forget this automatically causes some flicker (each line is updated only every 2nd frame).

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Are you sure there's absolutely not a single game-concept that would benefit from this technique?

 

Mabe it could be used for a scrolling background for a shootemup?

 

 

 

 

Scrolling causes problems with interlace unless you animate at only 30fps, otherwise you get this comb or strobing effect.

 

You don't notice it that much on live action or antialiased stuff on modern consoles, but on the 2600, it would be pretty annoying.

 

One thing you might be able to use it for is to interface with 3D LCD goggles. Most LCD goggles designed to be used with special VHS or DVD videos separate the two images by field. These are now quite inexpensive.

 

http://www.i-glassesstore.com/h3dvidviewsy.html

 

If you attempted to drive goggles like that with a regular 2600 kernel or via any other console that outputs "noninterlaced" video you'd only wind up with an image on one side of the goggles, most likely, assuming the synchronizer loses sync and blanks out every other field.

 

Maybe someone should buy a pair and see what happens with a standard kernel vs. interlaced.

 

You could probably write a port of Subroc 3D this way.

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well heres a question, we know the 2600 cant PLOT more than X graphic elements horizontally, but in its 'highest resolution' what is the number of horizontal pixels across? even though it cant fill all those pixels, that would still give you the resolution and aspect ratio. so, the 525 & 260 would stay the same. but the other number would be the actual horizontal resolution (even thought it may only be able to fill 1/2 or 1/3 of that with image....)

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Hi there!

 

well heres a question, we know the 2600 cant PLOT more than X graphic elements horizontally, but in its 'highest resolution' what is the number of horizontal pixels across? even though it cant fill all those pixels, that would still give you the resolution and aspect ratio. so, the 525 & 260 would stay the same. but the other number would be the actual horizontal resolution (even thought it may only be able to fill 1/2 or 1/3 of that with image....)

 

The normally visible, non-interlaced NTSC resolution would be 160 double-width pixels * 192 lines.

(This ~ matches a C64 in Multicolor mode.)

 

Greetings,

Manuel

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so even tho its technically 320 X 260 or 525,

No, it isn't 320 x anything. It's 160. Stop confusing the issue... it's confusing enough as it is.

 

With regards to the 2600's sprites, the most accurate thing to say is that their maximum resolution is 1 color-clock horizontally by 1 scanline vertically.

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WOW! So much for trying to get a 'straight' answer...lol. Let me rephrase... From a 'practical', what an original (aka Non-Home Brew - Retail) game used as a resolution is what I'm shooting for. The best I think is 160x192 which does makes sense. I'm not denying the theoretical 160x262/525 - but what I'm looking for is what the actual games used.

 

Most games I have tried *appear* to be using the 160x192... The only exception I have seen (or perhaps noticed) is running Sneak'N'Peek.

 

Right when you start the ROM up on an emulator the path and the person walking up is cut off at the start under any emulator I've tried - No matter what resolution I set. If I try to adjust the screen then the top portion of the display runs off the screen. Play it on a real 2600 and you'll see what I mean.

 

Nonethless, the answer I believe I'm looking for is 160x192. Under this assumption, the possibly closest resolution settings under an emulator (which doesn't support *exact* resolutions but 'standards') is:

 

Atari 2600 actual- 160x192 ----------------Emulator- 320x200

Atari 5200 actual- 320x192 ----------------Emulator- 320x200

Atari 7800 actual- 320x200(240/242) -----Emulator- 320x240

Atari Jaguar actual 768x567----------------Emulator - 800x600

Intellivision actual 192x160 ----------------Emulator - 320x200

ColecoVision actual 256x192---------------Emulator- 512x384(x2 size)

SMS actual 256x192-------------------------Emulator- 512x384(x2 size)

NES actual 256x224(240)-------------------Emulator- 400x300

TG-16 actual 256/320x256------------------Emulator- 400x300

Sega Genesis-CD-32X 320x224 -----------Emulator- 320x240

Super Nintendo 256x224--------------------Emulator- 400x300

 

I've spent *a lot* of time researching this info (actual resolutions). I couldn't believe the difference in opinions on some of these systems. Most difficult is the 2600, 7800, NES, TG-16. Seems to be several different viewpoints. However, I went with the most logical and generally accepted against the facts. Some (as you can see) I still undecided on (IE NES & 7800 - Notice the alternatives in parantheses).

 

Don't mean to drag this out for so long, but for the most part I was basically using 800x600 (Older Radeon) or 1024x768 (New Radeon) with hardware stretch for everything. Recently, I started taking note of distortion and aspect ratio in respects to image. Particularily with Rygar on the NES. Characters looked smaller and fatter. Then I realized the problem and changed resolution settings and the game look *much* better than before (Closer to the *real* console display).

 

Obviously, the 2600 is a *very* high priority with respects to this as well. And although the proud owner of a 4-switch wood grain and 150+ cartridges, sometimes emulation is my only or better option for playing. Nonetheless, I want the image being displayed via emualtor to match the actual display of a real 2600 as close as possible.

 

The specific numbers (ie 160x192) become even more important now as Direct X 9 supports specific resolution and outputing (So I've read). Hopefully with time, emulators will also allow this to be done (Some already do). In other words, for the user to select the exact resolution they want the emulator to run a game at. For now, I'm trying to come as close as possible with the 'basic' available resolutions.

 

Again, I apologize. Call it the perfectionist that I am (Just ask my wife...lol)

 

Thanks again.

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Atari 2600 actual- 160x192 ----------------Emulator- 320x200

That might be to small for some games (esp. PAL but also some NTSC games), IMO 320x240 is a better choice.

 

How is it too small for some NTSC games? Again, please excuse my ignornance, but if the actual display used by the games is 160x192, how is 320x200 not big enough?

 

160 less than 320

192 less than 200.

 

Why/how is 320x200 an issue? Could you please explain? Let me clarify again and state I am an NTSC user and are only concerned with *Original* *Retail* games - nothing 'Home Brew'.

 

Thank you.

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Why/how is 320x200 an issue?  Could you please explain?  Let me clarify again and state I am an NTSC user and are only concerned with *Original* *Retail* games - nothing 'Home Brew'.

Since it is completely up to the programmer of a game to decide how many (visible and invisible) scanlines a game produces, some games (e.g. Hole Hunter) display a few more scanlines than 200.

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When specifying these things, it's easier, in my opinion, to separate the 2600 into 2 displays:

 

1. A 2 color playfield display that's 40 pixels across

 

2. Dual single color sprite (player/missile) engines that produce pixels 1/4 the width of playfield pixels, although they cannot span the screen. This is why it's deceptive to say 160. They only provide limited areas of higher resolution.

 

As has already been pointed out, you can make as many lines visible as you want, so the vertical resolution isn't set in stone (although it's subject to the limitations of the broadcast standards).

 

That said, in theory you would need a display that can handle a 160 x 220(ish), and in practice you'll need to double up on the horizontal pixels (this is where people are getting 320 from) to make them the right aspect ratio (since they're wider than tall). You might want to display some left and right border area as well.

 

-Bry

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