UltraPIF timings question

[ConsoleRefresh]

Hi Jago85.

This is not an issue but a Quick Question. Does a Pal console with UltraPIF play NTSC games at exactly the correct speed? Or are there any slight discrepancies vs an actual NTSC console?

thanks for replying if you can.

thank
Nick

[jago85]

Hi Nick,

the video clock is adjusted as close as possible using the integrated clock generator circuit. I cannot measure how accurate it really is, but it should be very close. OSSC displays 60 Hz, while playing NTSC games on an unmodified PAL console would display 61 Hz.

Regards,
Jan

[VirtuaVespa]

Hi Jan,

Can I ask if we can get PAL colour timing with true 60hz (for 'PAL60') with this? I was under the impression that the subcarrier uses the same crystal as the 'game timing' so if that's changed to an NTSC one the colour timing gets changed, are you injecting two different timings into the N64?

Thanks

[jago85]

Hi Jan,

Can I ask if we can get PAL colour timing with true 60hz (for 'PAL60') with this? I was under the impression that the subcarrier uses the same crystal as the 'game timing' so if that's changed to an NTSC one the colour timing gets changed, are you injecting two different timings into the N64?

Thanks

Hi,

the UltraPIF does not generate two timings but exactly one clock which is fed into the chips of the N64 (RCP and video encoder). From the MX8350 datasheet, this is 48.681812 MHz for NTSC and 49.65653 MHz for PAL.

For an NTSC game on a PAL N64, the video clock is adjusted to the NTSC frequency. I don't have the technical background to claim this is 'PAL60'. But the output will be 60 Hz. And yes, changing the base clock will also change the timings associated with it.

I haven't done much work with the composite signal overall. Most of the testing I've done has been with RGB or HDMI mod. I also only have one TV that still has a composite input. And that is already an LCD TV. All versions of the N64 video encoders have pins that can switch between PAL and NTSC. At least that's what I assume they do. When I connect this pin of the video encoder to the FSEL signal of the UltraPIF, I always had a picture output. But I assume that was not 'PAL60' but 'NTSC'. I'm sure the result depends on the TV used.

[VirtuaVespa]

Thank you for this reply and great insight. I do believe you are correct in that if you use NTSC timing on a PAL N64 you would also need to set the encoder to NTSC. I am not technical either but I was hoping to achieve 'PAL60' since PAL colour space is better than NTSC (CRT S-Video looks really amazing in PAL). I guess some research is needed into seeing if crystal timing can be isolated for the encoder but that is way too complex for me lol

Have a good Xmas, Jan and thank you for your reply and knowledge.