Game Genie Decoder question

Discuss emulation of the Nintendo Entertainment System and Famicom.

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sleepy9090
Posts: 81
Joined: Fri Aug 22, 2008 10:04 am

Game Genie Decoder question

Post by sleepy9090 » Wed Sep 03, 2008 10:36 am

Hello all,

I was bored and coded a game genie decoder in C# after reading a few docs on how it works. The problem I'm running into is this:

When I follow how it works reading this doc:
http://tuxnes.sourceforge.net/gamegenie.html
or this one
http://nesdev.com/nesgg.txt

we take for example this code (as in the above text): GOSSIP
translates to (as in the above text): address = 0xD1DD, data = 0x14

When I download other programs that already have been coded and enter the same code it translates to: address = 51DD data = 14



So either the author is wrong or I am missing something? Any help would be appreciated.

sleepy9090
Posts: 81
Joined: Fri Aug 22, 2008 10:04 am

Post by sleepy9090 » Wed Sep 03, 2008 11:10 am

I figured it out, appears the text file was wrong, when decoding the code the text did not explain to make the high bit low if it is high and not touch it at all if it is low in the address conversion.

So basically a quick fix:
if (bitThirteen == "1")
{
bitThirteen = "0";
}

durr
thanks

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