Atari TIA and limitation question

[Uzumaki]

Sometime ago people was able to prove that Atari can do 480i but virtually no game used it because that's rather challenging to do. Theoretically can 2600 do 720i or even 1080i on modern TV? The only issue I could see is that composite and S-Video didn't support that mode as they were around before higher resolution TV came about so some TV may refuse non-240/480 signal on composite and S-Video.

 

Another question, can one fake wide screen mode by having more on screen pixel before calling h-sync?

[Cybearg]

There's a bigger issue of how many cycles your processor has. Maybe you can hit 480i, but will you have enough processor power left over to actually do anything?

[+SpiceWare]

Processing time isn't a problem for 480i, as it's the same as for 240p¹. The main problem with 480i is flicker.

 

The scanline count of TIA is totally under software control. However, adding additional scanlines results in a slower framerate as the time it takes for each scanline to be output is fixed. The decreased framerate of a 720 or 1080 image would result in a severely out of spec signal. It's highly doubtful anything would show it.

 

I've not seen any TIA tricks that could output more than 160 pixels per scanline.

 

 

¹ 240p is the modern nomenclature for the Atari's 262 scanline display.

Edited March 29, 2013 by SpiceWare

[raindog]

I don't think 480i creates a problem with running out of cycles, it just isn't that different than doing 30Hz flicker. If you're clever, maybe someone with a sharp eye can tell that you're displaying a slightly flickery 160x480 image rather than a slightly less flickery 160x240 image, but it just doesn't get you that much.

 

As for the other formats, the 2600 produces an NTSC (or PAL or SECAM) analog signal. HDTV is digital, at least in the US. Even if you have a monitor that'll take a 720i analog signal (which isn't a legal HDTV resolution, btw, but if it were, it would use half the bandwidth of 720p and less than half the bandwidth of 1080i) and a 2600 that's modded to produce it somehow, you'd have the same 16.67ms to produce 460800 pixels (one field of a 720i frame) that you currently have to produce 38400 pixels (one field of a 480i frame). And it's not like the TIA is going to magically get the ability to produce smaller pixels in the players, missiles, playfield or ball.

 

So it may be possible to produce such a signal for all I know, but forget about displaying anything useful, and forget about getting your game to work on a stock 2600.

 

As for simulating widescreen, the way the Wii did it was to compress everything horizontally so that when your HDTV stretches the image, it appears normal. I guess you could make a game with especially tall and narrow graphics if you meant for it to be viewed on a 16x9 screen, stretched. Or you could letterbox your game, have the HDTV zoom instead of stretching, and use the extra black space for more game logic. Either way, you don't get any extra cycles per scanline just because it's displayed wider. The TV will move on to the next scanline whether your kernel is ready or not.

[Keatah]

Output thousands of lines and rotate the screen 90 degrees.