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PostPosted: Thu Feb 23, 2017 9:50 am 
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Here is a silly question.
Would an unmodified version of Contra run correctly on an Aladdin Deck Enhancer system if it was put onto a similar cartridge board as Micro Machines?

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PostPosted: Thu Feb 23, 2017 10:12 am 
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In an unmodified front loader, it would probably blink. Codemasters cartridges use a software-controlled CIC stun circuit, and I assume the Aladdin is the same way. So hacking Contra from mapper 2 to mapper 71 would need a few changes.

  • A routine to operate the CIC stun circuit by writing to even and odd $E000-$FFFF.
  • Move all mapper writes during operation to $C000-$FFFF, preferably $C000-$DFFF. Writes to $8000-$BFFF in particular will not change the PRG bank.

Open Contra in FCEUX for Windows, set a breakpoint on writes to $8000-$BFFF, and play through. Does it stop?


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PostPosted: Sun Mar 26, 2017 7:24 pm 
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Also dont forget that Codemaster's mapper does not have bus conflicts, UNROM does.


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