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Re: Name of this game?

Posted: Sat Jan 08, 2022 10:52 am
by MaskRomz
Dwedit wrote: Tue Jan 04, 2022 3:53 pm US version of Master Chu is Mapper 11, Taiwanese version is either Mapper 133, or Mapper 79, same program works on both boards. That board seems to be Mapper 79, not 133.

But if you really wanted to mapper-hack a game to work on Mapper 79, I guess you could. To hack a CNROM game, you'd change the write address from 8000-FFFF to be 5F00 instead. Would need to fully playtest the game to verify that the mapper hack worked.
I need information about this pcb MB-91<H> I found informations about MB-91<A> and MB-91<E> but nothing about H version, know where I can find this?

Re: Name of this game?

Posted: Mon Jan 10, 2022 5:25 pm
by MaskRomz
pcb MB-91<H> is mapper 79 or mapper 11?

Re: Name of this game?

Posted: Tue Jan 11, 2022 5:08 am
by aquasnake
Connect the output pins of the two latches (2bit D flip-flop trigger) and properly scramble the bit order. When the corresponding output levels are the same, it works safely. If not, an IO conflict will be triggered, causing the hardware to burn down

I strongly oppose this kind of protection, which may be the most radical hardware practice

Re: Name of this game?

Posted: Wed Jan 12, 2022 8:44 am
by Dwedit
Did Mapper 79 have that protection, or was it just Mapper 133?

Re: Name of this game?

Posted: Wed Jan 12, 2022 10:10 am
by NewRisingSun
I don't know what scrambled bit order he means.

Re: Name of this game?

Posted: Thu Jan 13, 2022 8:52 pm
by aquasnake
wild guess

The register initialization routine must be run in time after startup. ASAP!

The IO always conflicts at the moment of startup, but there will be no problem for a short while. After that, the current drops down

If you dump 32K Prom directly without proper dump script writing to the register in advance, the IO will be completely short circuited after a certain period of accumulation, and even the dumper will be damaged

Re: Name of this game?

Posted: Fri Jan 14, 2022 10:18 am
by Dwedit
Every owner of a NES has inserted a game then had it fail to boot properly due to the cartridge not having a solid connection.
Does this mean that a cartridge with this kind of protection would damage a console if it was powered on but in a not-yet booted state? Or even if you powered it on while holding Reset?

Re: Name of this game?

Posted: Fri Jan 14, 2022 10:31 am
by Ben Boldt
Won’t that just burn out the latch chips in the cartridge? It seems it just connects the conflicting outputs of the latches together in your drawing. When the latches burn out, everything should be fine/unprotected as long as the 7805 in the console didn’t burn out?