Search found 522 matches

by Fiskbit
Wed Sep 28, 2022 2:44 pm
Forum: NESdev
Topic: Weird PPU writes
Replies: 26
Views: 6446

Re: Weird PPU writes

Some additional thoughts: The 3rd version of N-K's palette glitch ROM doesn't write to palettes at all in the normal case. Instead, it turns rendering off mid-screen, and when rendering begins again on the next frame, v is $3F10, which is supposedly a 'safe' value. In this ROM, the corruption depend...
by Fiskbit
Wed Sep 28, 2022 1:51 pm
Forum: NESdev
Topic: Weird PPU writes
Replies: 26
Views: 6446

Re: Weird PPU writes

I've put a little bit of time into this and it looks like the issue is related to the value of v when rendering begins. In both places one place where Vectrex28 encountered this, rendering is turned on mid-screen with v pointing into palette RAM ($3F01 and $3F04 ). [Edit: This results in $3F00 being...
by Fiskbit
Tue Sep 27, 2022 4:50 pm
Forum: NES Hardware and Flash Equipment
Topic: Help collecting pictures of CPU and PPU packages
Replies: 48
Views: 2066

Re: Help collecting pictures of CPU and PPU packages

Ah, gotcha. I mentioned the B and D heatspreaders earlier, but I think it must've gotten lost in the thread! Nintendo was very worried about PPU heat. Many early PPUs have some kind of rubber heatsink under the chip, others have these heatspreaders, and anything in an always-on environment (includin...
by Fiskbit
Tue Sep 27, 2022 4:29 pm
Forum: NES Hardware and Flash Equipment
Topic: Help collecting pictures of CPU and PPU packages
Replies: 48
Views: 2066

Re: Help collecting pictures of CPU and PPU packages

I feel like I'm missing something here. Nintendo used heatspreaders like this on many PPUs, with the chip name stamped into the metal. Attached is an image from Lockster (cropped down a bit to fit on the forum) with B and D examples.
by Fiskbit
Tue Sep 27, 2022 3:55 am
Forum: NESdev
Topic: Weird PPU writes
Replies: 26
Views: 6446

Re: Weird PPU writes

Vectrex28 seems to have encountered this palette issue on an AV Famicom when doing mid-screen palette updates. Writing 3F 00 00 00 to $2006 after the palette write or writing a full palette both fix it. I guess we can call this confirmed at this point and just need to work out the details of what ex...
by Fiskbit
Tue Sep 27, 2022 3:40 am
Forum: NES Hardware and Flash Equipment
Topic: Help collecting pictures of CPU and PPU packages
Replies: 48
Views: 2066

Re: Help collecting pictures of CPU and PPU packages

I don't have any of those, but I do have an RC2C05-03, which is currently missing a photo, so I'll take a picture of that. I also have a clean RP2C02D-0, so we can have a better photo than the current one that has a weird line through it. I'm also curious about why an "RP2C03G" is listed ...
by Fiskbit
Mon Sep 26, 2022 12:51 am
Forum: NESemdev
Topic: Count Errors Test ROM and some new DMC glitch info
Replies: 57
Views: 4824

Re: Count Errors Test ROM and some new DMC glitch info

Lockster has run my dmc_dma_implicit_stop_test on different 2A03G's in the same console. He found that his 1987 and 1989 G's fail (no 4-cycle blips) and two 1991 G's pass (yes 4-cycle blips). This confirms that the behavior is definitely caused just by differences in the CPU and that there are at le...
by Fiskbit
Sun Sep 25, 2022 2:17 am
Forum: NES Hardware and Flash Equipment
Topic: Help collecting pictures of CPU and PPU packages
Replies: 48
Views: 2066

Re: Help collecting pictures of CPU and PPU packages

Nice to have more RGB PPUs pictured! Do you happen to have any full-chip pictures of the RP2C03B, RP2C04-0001, or RP2C04-0004? They're cropped down on the wiki because the pictured chips have heatsinks on them. I can supply images of B and D chips with heatspreaders, if those are interesting. I've n...
by Fiskbit
Sat Sep 24, 2022 8:33 am
Forum: NESdev
Topic: SMB1 Hacking
Replies: 18
Views: 1660

Re: SMB1 Hacking

I've merged them, except for Change to Winter Graphics? because the posts wouldn't be contiguous in this thread. That topic looks finished, though, so I think there's no harm in leaving it separate.
by Fiskbit
Thu Sep 22, 2022 7:22 am
Forum: NESdev
Topic: Does 30 fps look too uncanny for a retro style game?
Replies: 14
Views: 837

Re: Does 30 fps look too uncanny for a retro style game?

30 FPS games feel noticeably less smooth than 60 FPS games. They're still fine, and a stable framerate is worth a lot, but almost every game on the NES is 60 FPS and so it's definitely noticeable when you play one that runs slower. That's not necessarily a problem, and being able to do more at a low...
by Fiskbit
Wed Sep 21, 2022 11:47 pm
Forum: NESdev
Topic: Gameplay actions that don't need to be done every frame
Replies: 7
Views: 538

Re: Gameplay actions that don't need to be done every frame

Zelda 1 has an interesting strategy where enemies all spawn 1 frame apart, which spreads out their background collision checks so they usually don't all happen on the same frame.
by Fiskbit
Mon Sep 19, 2022 9:04 pm
Forum: Reproduction
Topic: Issue with repro of "The Legend of Zelda Redux"
Replies: 8
Views: 577

Re: Issue with repro of "The Legend of Zelda Redux"

Not sure about the file... I think I took special attention to use what the hack requires The problem isn't your source file. The patching process is turning your 128 KB input ROM into a 177 KB output ROM. Files only increase in size from patching if the patch includes changes that are beyond the e...
by Fiskbit
Mon Sep 19, 2022 6:12 am
Forum: Reproduction
Topic: Issue with repro of "The Legend of Zelda Redux"
Replies: 8
Views: 577

Re: Issue with repro of "The Legend of Zelda Redux"

Got it, sorry for the confusion regarding the headers. The file size is still bizarre, though; the resulting ROM should not be 177 KB. And yeah, I wrote the MMC1 animation stuff hoping they'd abandon MMC5, since they switched to it specifically for background animation. Knowing that people insist on...
by Fiskbit
Mon Sep 19, 2022 3:57 am
Forum: Reproduction
Topic: Issue with repro of "The Legend of Zelda Redux"
Replies: 8
Views: 577

Re: Issue with repro of "The Legend of Zelda Redux"

The MMC1 version of this hack, which is indeed what you should be using, requires different hardware from the original Zelda. Instead of an 8 KB CHR-RAM chip, it needs a 32 KB one to support the animated backgrounds. You're seeing animation problems, suggesting this is your issue. Separately, I'm ba...
by Fiskbit
Thu Sep 15, 2022 4:39 am
Forum: Homebrew Projects
Topic: Counting Button Presses
Replies: 5
Views: 638

Re: Counting Button Presses

Indeed, a normal button press is probably almost always longer than a frame. For games with tricks that require one-frame taps, such as the 'screen scroll' glitch in Zelda where Link wraps from one side of the screen to the other, people usually come up with some unusual method of pressing to make i...