Search found 4916 matches

by Dwedit
Mon Mar 18, 2024 10:26 pm
Forum: NESdev
Topic: Forbidden Four: Space Bounty
Replies: 1
Views: 70

Re: Forbidden Four: Space Bounty

Would suggest removing the BPS file, when applied to an empty file, you get most of the ROM data from the other games. Not enough to actually run the game though.
by Dwedit
Thu Mar 14, 2024 3:06 pm
Forum: NESdev
Topic: NTSC timing questions
Replies: 7
Views: 515

Re: NTSC timing questions

Missing dot also screws up game captures (next 16 scanlines have a curve to them), and jitters on real TVs. You generally don't see this unless you play with the vertical hold knob, but the jittery scanline 0 is real.
by Dwedit
Wed Mar 13, 2024 10:47 am
Forum: NESdev
Topic: NTSC timing questions
Replies: 7
Views: 515

Re: NTSC timing questions

"in 341 pixel resolution we only have 227.5 samples of color" The 341 pixels also includes the vblank hblank, vsync horizontal sync, colorburst, and overscan area. The actual visible area is the 256 pixels. So then you have about 170.6666 "pixels" worth of color information. But ...
by Dwedit
Sat Mar 09, 2024 9:28 pm
Forum: NESdev
Topic: nescartdb submission system expectations
Replies: 14
Views: 2406

Re: nescartdb submission system expectations

Static doesn't mean no JS.
by Dwedit
Sat Mar 09, 2024 2:42 pm
Forum: Newbie Help Center
Topic: NES Game I wrote in 1990
Replies: 11
Views: 615

Re: NES Game I wrote in 1990

Which OCR software is freely available and good for code? Shouldn't have to retype stuff when scanners and OCR exist.
by Dwedit
Sat Mar 09, 2024 12:23 pm
Forum: Other Retro Dev
Topic: GBA flashcart abnormal behavior in NDS
Replies: 2
Views: 212

Re: GBA flashcart abnormal behavior in NDS

The scratchy noises happen any time a GBA game crashes. The game is still playing DMA sound, and when the vblank interrupt doesn't run to reset the sound pointer, it just keeps playing forever. Mother 3 uses FLASH512_V13 as the save type, not battery-backed SRAM. As for why the game is crashing? No ...
by Dwedit
Sat Feb 24, 2024 10:46 pm
Forum: NESdev
Topic: MMC5 and third pattern nametable
Replies: 30
Views: 2228

Re: MMC5 and third pattern nametable

When it's time to fetch the sprite graphics (around x=257), it does bank switching to make the sprites come from another graphics bank. Then when it's time to fetch background tiles again (around x=337) it switches back.

Also image is missing now?
by Dwedit
Sat Feb 24, 2024 6:01 pm
Forum: NESemdev
Topic: How are SFX played over music?
Replies: 7
Views: 513

Re: How are SFX played over music?

I assume you just play another sound effect to stop the charge sound?

Playing song F0 is used by Mega Man 5 to stop music.
by Dwedit
Fri Feb 23, 2024 3:32 pm
Forum: NESdev
Topic: Running mapper 206 as MMC3
Replies: 8
Views: 476

Re: Running mapper 206 as MMC3

So in other words, Nintendulator NRS (and not actual Nintendulator) is ignoring the mirroring state from the iNES Header, not performing the boot-time write to the A000 register, and instead you just get Vertical Mirroring regardless of what the NES header says. So that just means that Nintendulator...
by Dwedit
Fri Feb 23, 2024 1:52 pm
Forum: NESdev
Topic: Running mapper 206 as MMC3
Replies: 8
Views: 476

Re: Running mapper 206 as MMC3

I just tested out 80 different mapper 206 games, and every single one of them worked fine (booted and scrolled correctly) when changed to mapper 4.

What game is specifically not working correctly?
by Dwedit
Fri Feb 23, 2024 12:02 pm
Forum: NESdev
Topic: Running mapper 206 as MMC3
Replies: 8
Views: 476

Re: Running mapper 206 as MMC3

It appears that no MMC3 games shipped that required hardwired mirroring, so no MMC3 cartridges with hardwired mirroring were ever produced. Except for Rad Racer II which used 4-screen. (Gauntlet was also 4-screen but was not MMC3) According to Quietust's post, Nintendulator is initializing the mirro...
by Dwedit
Fri Feb 23, 2024 12:40 am
Forum: NESemdev
Topic: How are SFX played over music?
Replies: 7
Views: 513

Re: How are SFX played over music?

Just tested out Megaman 4's NSF. Init is 8003 and play is 8000. If you call Init with a sound effect number while the music is playing, it will play a sound effect while continuing to play the music. It works in some games, but not others. Some NSFs use a track replacement lookup table at the beginn...
by Dwedit
Thu Feb 22, 2024 2:02 pm
Forum: NESemdev
Topic: How are SFX played over music?
Replies: 7
Views: 513

Re: How are SFX played over music?

I haven't tried it yet, but what happens if you call Init (specifying sound effect number) without clearing the state first?
by Dwedit
Wed Feb 21, 2024 9:31 pm
Forum: NESdev
Topic: MMC5 and third pattern nametable
Replies: 30
Views: 2228

Re: MMC5 and third pattern nametable

Post said that it synchronizes to the two NT reads at end of scanline, then counts down 256 dots or 128 total memory accesses.
by Dwedit
Wed Feb 21, 2024 2:39 pm
Forum: NESdev
Topic: MMC5 and third pattern nametable
Replies: 30
Views: 2228

Re: MMC5 and third pattern nametable

Value of attribute doesn't matter, all that matters is that it was a fetch *done by the PPU itself* from an attribute table. It's watching for which address got fetched from. Nametable addresses: 2000-23BF 2400-27BF 2800-2BBF 2C00-2FBF Attribute table addresses: 23C0-23FF 27C0-27FF 2BC0-2BFF 2FC0-2F...