Help fix a famicomclone from PAL-D to PAL

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byemu
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Help fix a famicomclone from PAL-D to PAL

Post by byemu »

I have a famicomclone,the PPU CPU and Crystal same as PAL famicom,
But it's a PAL-D system,why they are different,how to fix to a PAL system.
lidnariq
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Re: Help fix a famicomclone from PAL-D to PAL

Post by lidnariq »

https://en.wikipedia.org/wiki/Broadcast ... _standards

Systems D/K should be like "normal" PAL but audio via the RF jack won't be receivable with System B/G/H equipment and vice versa.

In practice, I'd be surprised if most receivers can't deal with both D/K and B/G/H.
Last edited by lidnariq on Sat Mar 18, 2017 5:31 pm, edited 1 time in total.
tepples
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Re: Help fix a famicomclone from PAL-D to PAL

Post by tepples »

The difference between PAL B and PAL D is the RF channel spacing. A replacement RF modulator circuit would solve it; I'm guessing changing out some passives would as well, but that'd be more complicated. So would using A/V outputs (composite video and mono analog audio) instead of RF outputs.
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byemu
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Re: Help fix a famicomclone from PAL-D to PAL

Post by byemu »

But I fond m2 base IRQ games on PAL-D famicomclone is OK,such as Gimmick.
but they play on PAL NES will have problem.

And some PAL game can not play on famciomclone PAL-D.
lidnariq
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Re: Help fix a famicomclone from PAL-D to PAL

Post by lidnariq »

My best guess is that your famiclone probably is what we've taken to calling a "Dendy", a famiclone designed for 50 Hz operation that's compatible with 60 Hz software. This is unrelated to System B vs System D.

I don't think there's any way to convert a UM6538-based system to act like it has a 2C07, short of actually replacing the PPU and CPU.
kazblox
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Re: Help fix a famicomclone from PAL-D to PAL

Post by kazblox »

PAL clone PPUs have altered logic from real PAL PPUs to render more dummy scanlines, so unless you do the work of God and snap your fingers so you can shift molecules around in integrated circuits without causing the end of the world, you will have to replace the clone PPU with a real 2C07.

You can leave the APU alone, but to make it perform like how a real PAL APU should, you need to alter the divider logic on the PCB so that it divides at 16 and not 15. This is fortunately easy, unlike the PPU issue.
Last edited by kazblox on Tue Mar 28, 2017 7:06 pm, edited 1 time in total.
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byemu
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Re: Help fix a famicomclone from PAL-D to PAL

Post by byemu »

I see,I give up.
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