Games with black bars on top and bottom

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Pokun
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Re: Games with black bars on top and bottom

Post by Pokun »

Regarding mirrored registers, commercial games do use mirrors although maybe no game have used this particular one yet. Emulators that doesn't mirror PPU address space correctly will for example break on Super Mario Bros since it uses mirrored palette entries in the code.


Fiskbit wrote: Tue Jul 12, 2022 7:26 pm Thanks, though I should've been more clear: I've seen the effect before, but I don't intend to play there on a rev A PPU myself to see the actual result. I also wouldn't be able to test a hack that makes it easy to access because on-cart VRAM on the Everdrive N8 Pro doesn't work properly on rev A PPUs (writes receive a corrupted value).
Have you reported this bug? The old Everdrive doesn't seem to get new updates anymore, but the Everdrive Pro may.
lidnariq
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Re: Games with black bars on top and bottom

Post by lidnariq »

Drag wrote: Wed Jul 13, 2022 10:51 am Excellent, thank you, because was interested in familiarizing myself with all of this recent info, but there's no way I'd be able to effectively search the forums and find it all.
I have an early draft here: https://www.nesdev.org/wiki/User:Lidnariq/PPU_glitches

It needs a lot of work, so please let me know if anything is unclear.
Ti_
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Re: Games with black bars on top and bottom

Post by Ti_ »

DRW wrote: Tue Jul 12, 2022 1:43 pm By the way, what do you think of my attempt? Disabling the background at a certain scanline and placing sprites on the black border to simulate a status bar, but without the hassle of actually implementing a proper status bar in a vertically scrolling game. Is this something any game actually did?
My "sand emperor" demo does this. Backgrounds disabled by blank chr.
And sprites swapped between left and right patterns (8x16 mode). One of spr patterns becomes also blank, while other use another sprite chr's than out of status bar. This gives extra characters for sprites and no needs of 8 sprites usage. Also it differs between ntsc and pal/dendy.
'1500' - 4 sprites:
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DRW
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Re: Games with black bars on top and bottom

Post by DRW »

Ti_ wrote: Sun Jul 17, 2022 1:48 am Backgrounds disabled by blank chr.
no needs of 8 sprites usage
In my case, the eight sprite usage is nothing that I need to implement specifically for this effect. Even before I thought of the status bar, the two player characters already were supposed to have up to four energy points. And since I use 8x16 sprites, I can place them in a way, so that they appear on the second row of the status bar and they still cance out all sprites that walk into either the first or second row.
My game "City Trouble":
Gameplay video: https://youtu.be/Eee0yurkIW4
Download (ROM, manual, artworks): http://www.denny-r-walter.de/city.html
Ti_
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Re: Games with black bars on top and bottom

Post by Ti_ »

DRW wrote: Sun Jul 17, 2022 3:58 am In my case, the eight sprite usage is nothing that I need to implement specifically for this effect. Even before I thought of the status bar, the two player characters already were supposed to have up to four energy points. And since I use 8x16 sprites, I can place them in a way, so that they appear on the second row of the status bar and they still cance out all sprites that walk into either the first or second row.
It's good until someone will play on emulator with disabled sprite limit.
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DRW
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Re: Games with black bars on top and bottom

Post by DRW »

Yeah, but if he does that, then "The Legend of Zelda" will look wrong as well, so why should I design my game around non-standard behavior in emulators?

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My game "City Trouble":
Gameplay video: https://youtu.be/Eee0yurkIW4
Download (ROM, manual, artworks): http://www.denny-r-walter.de/city.html
Fiskbit
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Re: Games with black bars on top and bottom

Post by Fiskbit »

Pokun wrote: Thu Jul 14, 2022 4:16 pm Have you reported this bug? The old Everdrive doesn't seem to get new updates anymore, but the Everdrive Pro may.
I haven't, but the Everdrive isn't the only thing I've seen misbehave on rev A consoles. Two other modern games I've tried on it have had similar issues. One uses CHR-RAM and shows bad graphics from the start (not sure if it's bad on the write or read, or both), and the other uses CHR-RAM and has bad data in the HUD after the console warms up (but the data is already written, so this is a read problem). Every contemporary game I've tried (even complex ones, like Napolean Senki (4-screen VRAM) and Just Breed (MMC5)) works just fine, so I'm not sure what the modern hardware is doing wrong.
Pokun
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Re: Games with black bars on top and bottom

Post by Pokun »

Hmm could it be chip access time is different on rev A so that newer faster chips fails? But if reading doesn't work correctly, CHR-ROM games would fail too I guess.
iNCEPTIONAL

Re: Games with black bars on top and bottom

Post by iNCEPTIONAL »

DRW wrote: Sat Jul 09, 2022 5:17 am I'm playing with the thought of doing this for my game, so I'd like to know:

Are there any commercial NES games that used the MMC3 IRQ during vertical scrolling to disable rendering in the first and last few rows?
The reason to do this: Due to TV overscan, it might be problematic to allow a character to move completely to the top or to the bottom of the screen since he might not be visible anymore. But if you set a hard line that the character cannot cross, then it might feel unnatural that you see a gap between a wall and the screen bottom, but the character cannot move between it, even though he would usually fit.

So, to overcome this, you could simply disable rendering for the first and last 16-24 pixel rows and make this the playfield border. This way, the character is never blocked from moving to visible parts of the screen, but he's not in danger of moving to the offscreen area either.

Of course, if you have a status bar, this is a non-issue, at least for one side of the screen. But did any games that didn't have a status bar ever reduce the visible screen by adding black bars?
I was actually thinking of adding 8 pixel or maybe even 16 pixel black bars to the top and bottom of my game, but for a slightly more novel reason, which is to use it to do a faux 3D effect where only some elements of the game pass over those bars to created the illusion that they're coming slightly out of the screen. And, when combined with the Pulfrich effect and a pair of glasses designed to work with this, which I'd like to include in the box if I ever made a physical copy, I think it could actually be a rather cool USP.
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