nesdev.com

There is an amusing bug with the most recent version of Nestopia UE, Castlevania US, either revision will fail miserably just after you enter the castle gates. You will see a glitchy background and instantly fall to your death. This does not happen with the European or Japanese cart, PlayChoice-10 or disk versions.

Make sure you don't have any "Cheats" loaded (Options -> Cheats), temporary or permanent, that don't match the specific game checksum. I've been bitten by this more than once.

Watching routine Ppu::Run you can easily see that the flag of VBLANK and the NMI are performed to cycles.hClock 681 (HCLOCK_VBLANK_0), 682 (HCLOCK_VBLANK_1) and 684 (HCLOCK_VBLANK_2) that is virtually one scanline after the VACTIVE (240) scanlines. This is fine for PPU_RP2C02 (NTSC) and PPU_RP2C07 (PAL) but not for PPU_DENDY that needs another 50 sleep scanlines. What I did was nothing more than adding these 50 scanlines first of the HCLOCK_VBLANK_0 that are performed only when the variable (ssleep >= 0) and this is true only in the case of PPU_DENDY.

This way I left intact the logic with which the routine work for NTSC and PAL, intervening only for Dendy mode because ssleep will always be -1 for PPU_RP2C02 and PPU_RP2C07.

I hope that I was able to explain well.

D'oh! I had some cheats enabled, I totally forgot about that. Disabling them fixed these games. Sorry about that silly mistake.

One thing that isn't a bug, Windows Nestopia UE 1.47 will crash if I try to load The Incredible Crash Dummies or Mickey's Safari in Letterland with the iNES 2.0 header set to the Acclaim MMC3 clone.