Do newer revision CPU/PPU work on older revision motherboards?

[hippy dave]

Hello
So I quite recently got myself my first real Famicom, I went for a red & white one for the full retro *aesthetic*, bought it from a seller who did a nice clean up/refurb, mod for composite output and 5v USB input etc.

It's a revision 7 board (HVC-CPU-07) with revision E chips. It's working great, none of the glitches of the really old revisions, but the one thing it turns out I miss is the readable OAMDATA/palette RAM of the G/H revisions, because I got a (clone) everdrive and like the option of using save states. Reloading a save state will trash the palette and turn most stuff black, so is unusable during gameplay, I can work around for games where I save at a point where it's about to refresh it all (eg SMB lives remaining screen or Metroid password screen, before returning to gameplay) but not all games have a convenient moment like that, plus it would be nice to be able to use it at any arbitrary point.

So hypothetically would it work if I swapped revision G or H chips onto my revision 7 board? IDK if I'm committed to this idea yet but would be good to know my options. I'd probably put sockets in if I were doing it.

--

Tangential revision-related question while I'm here: I read in older threads that the red & white Famicoms that have the FF logo on the front sticker are always newer models that have a one-piece motherboard, whereas mine has the older design with the RF and power stuff on a separate board. It does have the FF logo on the sticker tho - is this a combination that actually happened back in the day, or is it more likely that the seller put a different sticker on? This one's just for curiosity.

Thanks! 

[P]

I don't really know but, it's entirely possible that some PPU revisions requires an extra resistor or something on a pin which another doesn't. It might be easiest if you look for HVC-CPU-07 boards with a newer PPU and also check that it doesn't have any new components around it.
HVC-CPU-07 and the rare HVC-CPU-08 mainly seems to be using PPU revision D and E from what I've seen, but I haven't looked very hard.


Nintendo sometimes swapped boards when doing repairs, so it's hard to say if it's the original board for the shell, for not mentioning the chance that a previous owner has repaired it.
The FF logo seems to mainly be used on newer Famicoms (probably GPM boards and later), but I doubt it can be guaranteed. If Nintendo's factories had a lot of the older boards lying around but only the newer shell, it would make the most sense to use the newer shell with the older board, as long as it fits.

Edit: Indeed the G-0 has a bug which requires some extra resistors according to this page.