PAR to GG???

[AleXstX]

Hi! Im new here and i have one question: how can i convert 0081:01(PAR) to GG? This is invicibility code for Kyoryu Sentai ZyuRanger(J) NES title, made by ReyVGM, all credits goes to him. I tried everything i know, tried with GGConvC but it dont work... the value needs to be 01 in order for code to work, but i am not that good in 6502 assembly...

[nolberto82]

You can't convert RAM addresses to Game Genie codes. For example:

0000:7FFF
Any address in this range can't be converted to game genie.

8000:FFFF
Any address in this range can be converted.

This is what you should have:

Invincibility
E441 D0 50 -  AIKTPGEI

E441 = The address is over 8000 so it can be converted into a Game Genie code.

[AleXstX]

You can't convert RAM addresses to Game Genie codes. For example:

0000:7FFF
Any address in this range can't be converted to game genie.

8000:FFFF
Any address in this range can be converted.

This is what you should have:

Invincibility
E441 D0 50 -  AIKTPGEI

E441 = The address is over 8000 so it can be converted into a Game Genie code.

So i can`t convert that RAM address to GG? What can i do then? Sorry, but i didn`t understand u quite well, im new to this, can you please explain better, if its not a problem?

[BigBossman]

I'm wondering about something on this too. I know you can't just outright change a PAR code to GG. But I've noticed that you can change a GG code to PAR. Normally, when you do this the PAR code won't start with 7E or 7F. Is it possible to convert a 7E or 7F code to the other PAR address (that you would normally get after converting GG to PAR)?

For example:
Combatribes SNES

the GG code for Infinite credits:
A2B3-A404

When you convert it to a PAR code it becomes:
009BE9CD

Is there a way to get it to its normal PAR address?
7E156409

I was thinking that if there's a way to convert it from the "7E" to the "00" code, that it might be possible to take that "00" code & turn it to a working GG code. But again, that's just a theory.

[thenewguy]

Only thing i know is 7E or 7F cannot be converted because there not consider snes gg codes.

[JLukas]

SNES $7E and $7F banks are RAM, which the SNES Game Genie doesn't support.

For the Comatribes example above, here's the original opcode usage:
$00/9BE9 CE 64 15 DEC $1564

The PAR code 009BE9CD replaces it with the following:
$00/9BE9 CD 64 15 CMP $1564

Changing the DEC (decrement) to CMP doesn't allow the game to subtract credits, which gives the same effect as the PAR RAM code 7E156409 (freezes credits value at 9)

There is no conversion formula to turn a SNES PAR RAM code to Game Genie. Instead, it needs to be done manually using a debugger to set a write breakpoint on the address (7E1564 in this case) and then watch for when it gets triggered.

[nolberto82]

So i can`t convert that RAM address to GG? What can i do then? Sorry, but i didn`t understand u quite well, im new to this, can you please explain better, if its not a problem?

If you have an address like 8E23:AD you can convert to game genie.
You can't convert RAM address to game genie like 0081:01 or anything below 8000.

The best way to make game genie codes is to use a debugger. Since you are talking about the NES you will need some basic 6502 knowledge. But if you are just trying to convert an existing PAR code it has to be over 8000.

[rimsky82]

RAM (Random Access Memory) is the area of memory that holds values, as kind of a scratchpad for the system. So if the game needs to know how many lives you have left, it checks the RAM. The Pro Action Replay device freezes values in RAM, so when the games checks for lives, it always reads a certain number.

The ROM (Read-Only Memory) is the instructions for the game. It tells the system to load the number of lives from RAM, decrement it, and store it back. The Game Genie device manipulates these instructions to achieve the desired effect, such as changing the decrement instruction to something else.

Because the PAR and Game Genie manipulate two entirely separate areas of the system memory, and are not directly related, codes can not be converted from one to the other.

What nolberto82 is saying, is that you can convert raw address/value pairs to GG, but they have to be changing a ROM address. For NES, thats in the $8000-$FFFF range. And because the NES, GB, GBC, and Game Gear use bankswitching/mappers, a compare value is usually necessary.

[OldSchoolGamer]

What nolberto82 is saying, is that you can convert raw address/value pairs to GG, but they have to be changing a ROM address. For NES, thats in the $8000-$FFFF range.

For the example 0081:01. The 0081 is the address and the 01 is the value. It has to be above 8000 to convert. So you take the last two digits of the address, which is 81, and the value which is 01, and you ignore the ":" and push both numbers together to get the number 8101. Now since 8101 is greater than 8000 it can be converted.

Is that what you mean when you say that it has to be greater than 8000 in order to convert it to a game genie code?

[Hybrid]

For the example 0081:01. The 0081 is the address and the 01 is the value. It has to be above 8000 to convert. So you take the last two digits of the address, which is 81, and the value which is 01, and you ignore the ":" and push both numbers together to get the number 8101. Now since 8101 is greater than 8000 it can be converted.

Is that what you mean when you say that it has to be greater than 8000 in order to convert it to a game genie code?

this will not work.
For "Kyoryu Sentai ZyuRanger"
to get a game genie code for the PAR code 0081:01 you would have to use a debugger use a read breakpoint on 0081
it breaks to here

$E43F:A5 81     LDA $0081 = #$00
$E441:D0 43     BNE $E486

this small snipet of code is what we should be concerned with changing the BNE to BEQ should effectively turn on the invincibility so
Address E441
Compare D0
Value F0
encrypted game genie code EYKTPGEI

[RyanfaeScotland]

I found it fasicinating when I first learnt how the GG and PAR worked, as a kid I just new them as these magic boxes that allowed you to cheat but occasionally screwed up your game. Who would have known several years down the line I'd be writing my own codes for them!

I could probably find it again but I don't suppose anyone here knows the 'encyption' algorithm for the GG, I was wanting to write a short program for converting memory addresses and values to Game Genie codes (more as a learning exercise than anything else as I know such programs already exist). On the subject, is the algorthim different for different versions of the GG? It's the Megadrive one I am interested in if so.

RHDN has some good documents on the GG if you'd like to know more: http://www.romhacking.net/?category=...o&title=&desc=

[rimsky82]

Actually, our own site describes the Game Genie algorithms quite well. You can find all of that information in the wiki.

The Game Boy and Game Gear shared the same algorithm, but the rest are different. I myself have written Game Genie converters for each system in javascript, flash (actionscript 4), php, and C#.

[RyanfaeScotland]

Nice one, thanks Rimsky, I'll check them out.

[Lazy Bastard]

I also wrote a guide to the various GG encryption schemes, which can be found in the Library: GG Encryption Schemes

[RyanfaeScotland]

I also wrote a guide to the various GG encryption schemes, which can be found in the Library: GG Encryption Schemes

Nice one, that's exactly the sort of document I was looking for. I searched the site as well and it didn't spot it, shouldn't a document like that turn up when entering "Game Genie" into the search field?

Thanks for writing and sharing Lazy Bastard.