On the wiki page, APU Frame Counter, do the APU cycle values work for PAL carts?
Did you read this line? 
Quote:
TODO: describe PAL
Zepper wrote:
Did you read this line?
Quote:
TODO: describe PAL
Yep. I saw that. But, I wasn't sure if it was referring to an earlier section or the tables.
If the numbers are not available, I can probably get away with scaling everything by 5/6.
It might be 15/16 instead if the "frame" counters aren't supposed to refer to actual video frames.
Nintendulator has some numbers for PAL...
No idea where they came from though.
Probably divide by 2 to get the Wiki's numbers.
No idea where they came from though.
Probably divide by 2 to get the Wiki's numbers.
Code:
const int FrameCyclesNTSC[5] = { 7456,14912,22370,29828,37280 };
const int FrameCyclesPAL[5] = { 8312,16626,24938,33252,41560 };
const int FrameCyclesPAL[5] = { 8312,16626,24938,33252,41560 };
Dwedit wrote:
Nintendulator has some numbers for PAL...
No idea where they came from though.
No idea where they came from though.
They all have a common ratio: 1039 / 932 (approximately 1.1148). I'm not sure what that is exactly.
That's close to 312/262*15/16 = 1.1164, presumably reflecting an assumption that the APU Frame Counter was supposed to keep the same ratio to a PPU frame on PAL as on NTSC. I have no PAL NES, or I'd make a test ROM.
tepples wrote:
That's close to 312/262*15/16 = 1.1164, presumably reflecting an assumption that the APU Frame Counter was supposed to keep the same ratio to a PPU frame on PAL as on NTSC. I have no PAL NES, or I'd make a test ROM.
That would make sense. They should have used 66495/59561. Maybe there is some rounding error when they converted to ints.
It's just enough different from the right ratio I have to wonder if it's deliberate.
The values I used for PAL were based on somebody else's findings, but they're not 100% exact like the NTSC ones are.