Mapper 182 Hardware?

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Mapper 182 Hardware?
by on (#148490)
I want to make a repro from Super Donkey Kong (Unl) [!].nes which is Mapper 182

It seems it is very similar to a regular TLROM / Mapper 4 game, but the address / data lines are swapped on MMC3 side.
How the data lines are swapped seems simple.
But I can't understand how they swapped the address lines :

Mapper 182 MMC3
A15 A14 A13 ~ A0
--------------------
$8000 -
100~0 ?

$8001 $A000
100~1 101~0

$A000 $8000 (addresses further scrambled, see below)
101~0 100~0

$A001 -
101~1 ?

$C000 $8001
110~0 100~1

$C001 $C000+$C001 *
110~1 ?

$E000 $E000
111~0 111~0

$E001 $E001
111~1 111~1

Any help?
Thanks in advance
Re: Mapper 182 Hardware?
by on (#148491)
It can't just be scrambled address lines, because writing to m182@$c001 is equivalent to writing to two different MMC3 addresses.
Re: Mapper 182 Hardware?
by on (#148492)
Thanks for the answer
So rebuilding the hardware needs some glue logic with TTLs?

How about converting the game to Mapper 4?
Is it just editing / replacing the reg-ports?
And un-scramble the data which is written to them?
Or there is something more than that?
Re: Mapper 182 Hardware?
by on (#148498)
FARID wrote:
How about converting the game to Mapper 4?
Is it just editing / replacing the reg-ports?

So long as the game doesn't try hashing its code like Earthworm Jim 2 does.
Re: Mapper 182 Hardware?
by on (#148526)
Yeah, hacking the ROM seems easiest here, if requiring additional work for each individual game.