atari7800 How to get more color in 320 modes (Without the high DMA)

[Ecernosoft]

Hey, I was wondering if this would be viable for games.

 

By using a DLI at the start of the screen (The very top) and switching PxC2 and CHARBASE between two values on each scanline, you can get 2bpp by alternating the even and odd scanlines per frame like in 160C. (Ex: color 1 on odd for first frame, color 1 on even for second frame)

 

This is for @Muddyfunster! Hopefully he'll give this some love. 😃

It's like having 320B with 320A DMA costs, more colors (9 instead of 7) AND the best 320 mode in my humble oppinion: 320C.

 

It would look something like this:

; The top two frames represent the even and odd frames, and the bottom represents what the person would probably see. The brown would be more of a  greenish color though. It would work more similarly to 5200 2bpp sprites. Having the "or color" be the color 3 in this case. So, it isn't 100% 320B capability, but with real 320B, you need to deal with "The curse" in which you need to have C2 or C3 paired with C1 to have C1 show up. I'm going to call this 320BI (320B interlaced). 

 

You can also do something similar w/ 320B to get T320BI (True 320B interlaced) to get 9 colors (10 with transparency) by alternating the pallete per scanline instead of a PxC2 color.

Hope this was useful! Tell me what you think.

 

Also, if you run out of VBLANK time, you can just alternate between the "Color 1" and "color 2" frames.

 

Edit: Have you guys ever tried this before?

Edited October 2, 2022 by Ecernosoft

[Ecernosoft]

Here's another example, this time actually being coded!

; Green + Yellow = Tan in this case.

320BI_test (1).a78

[+Muddyfunster]

I do find these kind of techniques fascinating. I tried something a bit similar back in the 80's on the ZX Spectrum, to get a funky "orange" from fast switching red and yellow patterns. It kinda worked, but on modern non-CRT displays, the effect isn't quite the same.

 

For developing games, I tend to steer away from flicker or artifacting effects because not everyone sees them the same way or not everyone has the same display. I always want to try to have a consistent experience for the player irrespective of whether they play on PAL or NTSC, LCD or CRT (the $1x issue with colours...). 

 

320 experimentation is something I plan to come back to as some point but first I have few other things I want to get done, one of which is A.R.T.I.

 

 

[Ecernosoft]

2 hours ago, Muddyfunster said:

I do find these kind of techniques fascinating. I tried something a bit similar back in the 80's on the ZX Spectrum, to get a funky "orange" from fast switching red and yellow patterns. It kinda worked, but on modern non-CRT displays, the effect isn't quite the same.

 

For developing games, I tend to steer away from flicker or artifacting effects because not everyone sees them the same way or not everyone has the same display. I always want to try to have a consistent experience for the player irrespective of whether they play on PAL or NTSC, LCD or CRT (the $1x issue with colours...). 

 

320 experimentation is something I plan to come back to as some point but first I have few other things I want to get done, one of which is A.R.T.I.

 

 

That's true. If you have a 30FPS display and no 60 or above FPS display, it won't look right. Or if you play on PAL it will flicker some.

Speaking of A.T.R.I. Are you going to sell that? And note if you use POKEY, it will be practically impossible to buy.

Also, when I brought my Atari to my friends house, they played quite a lot (They too are partial atari fans, especially after their experience) and they had quite the time with Danger Zone. It was the public demo and since I used Concerto they couldn't hear the music, but they had a lot of fun!

[+Muddyfunster]

33 minutes ago, Ecernosoft said:

Speaking of A.T.R.I. Are you going to sell that? And note if you use POKEY, it will be practically impossible to buy.

A.R.T.I. still has a lot of work to be done before it's complete.

 

I'm not sure why any game that would need POKEY would be hard to buy. Mostly they would be available from AtariAge with a HOKEY on the cart, so fairly easy to get hold of. Also POKEY alternatives have been around for a while, like POKEYMax and more recently "HOKEY".

 

If I get around to making the ROM available to buy separately then there will be lots of ways to play that. For multi carts (Concerto, Dragonfly and the upcoming GD7800) they all support POKEY or some modern equivalent like HOKEY. Modern emulators pretty much all support POKEY (varying levels of accuracy but a7800 is great) and the MiSTer core supports POKEY. 

 

So not sure I follow why it would be practically impossible  

 

33 minutes ago, Ecernosoft said:

Also, when I brought my Atari to my friends house, they played quite a lot (They too are partial atari fans, especially after their experience) and they had quite the time with Danger Zone. It was the public demo and since I used Concerto they couldn't hear the music, but they had a lot of fun!

Good stuff, glad you had fun with it

 

[Ecernosoft]

3 hours ago, Muddyfunster said:

A.R.T.I. still has a lot of work to be done before it's complete.

 

I'm not sure why any game that would need POKEY would be hard to buy.

 

Atariage is weird like that. I too wondered why @Albert doesn't just use HOKEY. I waited over a year for Bently bear and it didn't become available.

  

3 hours ago, Muddyfunster said:

 

Good stuff, glad you had fun with it

 

It wasn't me.... more my friends. We also played other games though.

Edited October 6, 2022 by Ecernosoft

[Albert]

9 minutes ago, Ecernosoft said:

Atariage is weird like that. I too wondered why @Albert doesn't just use HOKEY. I waited over a year for Bently bear and it didn't become available.

I am using the HOKEY for all the new games.  It will make its way to the older games as well, I just don't have a large number of these new boards yet.

 

 ..Al

[Ecernosoft]

1 hour ago, Albert said:

I am using the HOKEY for all the new games.  It will make its way to the older games as well, I just don't have a large number of these new boards yet.

 

 ..Al

Ok. Thanks for the info!

[Astal4]

If you want more color, I'd switch to 160 and do higher color there, and scroll the screen to fit everything you would've in 320, or make the sprite half as wide, you can get a lot more on screen colors that way, and it is a good tradeoff for a 1984 console. There's tricks as well but color tricks on the 7800 could cause lots of issues because of the color shift issues it has already when not using tricks.

[Ecernosoft]

15 hours ago, Astal4 said:

If you want more color, I'd switch to 160 and do higher color there, and scroll the screen to fit everything you would've in 320, or make the sprite half as wide, you can get a lot more on screen colors that way, and it is a good tradeoff for a 1984 console. There's tricks as well but color tricks on the 7800 could cause lots of issues because of the color shift issues it has already when not using tricks.

Unlike 160A this runs in 320 mode, making 160A less nessesary.

[Astal4]

The artifacting effects will not work well, maybe at all through a retrotink/OSSC/other on an LCD, which is how MANY people play. I'd recommend against it, it might've worked ok in 1986 through an RF signal, but something like S-Video onto an LCD through a Retrotink you'll just have weird looking graphics and no extra colors.

[Traxx]

I'd focus on gameplay instead of more colors,you can have the highest color count for any game on 7800 but if it's riddle with bugs and is not fun to play then the color count won't make much difference.

Edited October 7, 2022 by Traxx

[Astal4]

4 minutes ago, Traxx said:

I'd focus on gameplay instead of more colors

This, if your game is colorful but shitty, it doesn't matter.

If your game has proper design/progression/etc, it could be in B&W on the 2600 and it doesn't matter. A good game is a good game from design, not from graphics. If you really want huge graphics from an Atari system there's also the Jaguar, pick the mode best for what you're doing, if that's high color, then 160 mode, if it's high resolution, then 320 mode, the system was designed in a specific way for a reason. There's strengths and weaknesses of a system and just do what is best for your game, not what ticks a checkbox.

 

Edit: you can also switch between modes, you're not locked into one from the start.

Edited October 7, 2022 by Astal4

[Ecernosoft]

18 hours ago, Astal4 said:

The artifacting effects will not work well, maybe at all through a retrotink/OSSC/other on an LCD, which is how MANY people play. I'd recommend against it, it might've worked ok in 1986 through an RF signal, but something like S-Video onto an LCD through a Retrotink you'll just have weird looking graphics and no extra colors.

I'm not artifacting, look at my example above.

Sure, it doesn't quite look as nice on LCD as it does on CRT but the only CRT I could ask to use is in rhode island at my gram's house.

18 hours ago, Astal4 said:

This, if your game is colorful but shitty, it doesn't matter.

You are right.

Also, I'm going to be totally honest right now: I am a terrible game-designer.

I have an idea. And then, I get a new one and really want to try it, but it doesn't work. So I try a new one, and again, and again, and things get messy real fast.

 

Edit: That's sort of why I'm making this post @Astal4. You guys are better game designers than I am. By far.

18 hours ago, Astal4 said:

Edit: you can also switch between modes, you're not locked into one from the start.

That's also true. Switching between 320B and 320C is useful since 320A and 320D are *Almost* identical.

Edited October 8, 2022 by Ecernosoft