FCEUX overclocking

[tepples]

Can your emulator play the Rick Rolled! demo?

[feos]

Can your emulator play the Rick Rolled! demo?

It's now optional
Config -> Timing.

Also, I couldn't set it up for new PPU at all, so I blocked overclocking for it.

[Eugene.S]

I've set 999 extra scanlines.
Tepples's overclock test rom shows 1264 lines/frame

[feos]

7-bit samples still can't be properly played at high overclocking. I can only limit PPU loops before they start, checking if 7-bit is already playing. If I check it during PPU loop itself and break it, there are clips.

So it has to be checked only before the loop, and then it's up to user to set proper value for extra scanlines. BTDD samples play okay at 90 maximum, but TMNT3 needs 200 in 2-1.

[Dwedit]

Works really well! Armadillo is a lot more playable once you remove the slowdown that plagues that game.

[furrykef]

Isn't it a given that changing timing specifications is going to break any kind of programming that relies on the spec being unchanged? Just look at early dos games like Bouncing Babies which become unplayable as CPU speeds increase, with certain manufacturers going as far as adding a "turbo" switch on the PC to flip the clock speed between a compatible one and a fast one.

I imagine few NES games don't wait for vertical blank at the end of every frame. The only case I can think of where you might not do it is when you're writing PCM audio to the DPCM delta counter, and few games did that.

[tepples]

If by "few" you mean "quite a few", I'll agree. Off the top of my head, I can think of Skate or Die 2, The Three Stooges, all Wheel of Fortune games, Joshua, Big Bird's Hide and Speak, Countdown, SCAT, Blades of Steel, Action 52 menu, Mito Koumon 1 and 2, and I think the US version of Bases Loaded. I wrote decompression tools for many of these several years ago. And when I used to hang out on Pocket Heaven years ago, I gained kind of a reputation for reminding the PocketNES developers that Big Bird's Hide and Speak still didn't work.

[furrykef]

Considering the huge library of NES games, that really isn't a lot, and most people aren't interested in most of those games. I'm not saying they're not worth supporting if possible, but I think most people really won't mind if a minor emulator feature isn't compatible with those games.

It's also only relevant when PCM audio is being played. At other times the game will probably wait for vblank like normal.

Hypothetically you could add an option to disable overclocking for frames where $4011 is written to directly, although in a few games this will be triggered at inappropriate times, such as the percussion in FF3's music. But the player probably won't mind if these games aren't overclocked.

[feos]

Hypothetically you could add an option to disable overclocking for frames where $4011 is written to directly, although in a few games this will be triggered at inappropriate times, such as the percussion in FF3's music. But the player probably won't mind if these games aren't overclocked.

Yeah, hypothetically.

[tepples]

I guess an emulator could detect more than 10 writes to $4011 in a frame and disable the extra post-render lines for that frame.