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determining hex addresses? (I know its been covered before)


ren6175

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Ok, I read several threads about using nesticle or fceued to determine hex addresses. Several of the threads have comments by GRG and the links are broken.

So here is my question.

I open up fceued and load the rom. I start the name table and the pattern table viewers. I see for example when I hover over "S" that it is found at tile 53 in the pattern table. If I want to change that "S" to a "T" then I know I need to point to tile 54. How do I determine the address that tells the game to point to tile 54?

I see in the name table viewer that there is a "PPU address". Is that what I need to use? If so what math do I need to use? I know that with the large helmet addresses I had to add 10 and 60 then reverse the numbers to find the location. Is this similar?

I really did try to find the answer myself. Thanks.

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It isn't as easy as just opening up a screen and being told. What you are asking for is actual hacking and sometimes it is super easy and other times very hard.

Here is an easy example:

1. Open up the rom in FCEUXD SP 1.07

2. Hit F2 on the TECMO Presents Screen to pause

3. Open up the Hex Editor and go to the PPU Memory

4. Search for PRESENTS in text [x21ED to x21F4]

5. Know P = x50 in hex there and PPU Viewer shows the same

6. Select the P (x21ED) and right click choosing to add a write breakpoint

7. Use the emulator Reset to reload the game (press F2 to unpause)

8. On the debug screen hit run until A, X, or Y = 50 [A will quickly on $8211]

9. Press up on the code area to see a few lines above $8211

10. LDA ($60),Y @ $ABF1 = #$50 so $ABF1 is a likely spot so type ABF1 in the "Seek To:" box and hit the seek to button

11. Move to the left side of the screen next to $ABF1 and at the bottom it will display the rom location [x16C01]

12. On the Breakpoints, edit the $21ED so write is unchecked

13. Hit Run

14. In the Hex Editor go to Rom File and move to x16C01

15. Change x16C01 to J

16. Use the emulator reset

17. If the P is a J now then you found the right spot [it is] else you would put back your breakpoint and skip the first 50 as it was wrong

The harder stuff appears when an address writes to another address and you have to backpedal through each change.

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Ok, that is a little over my head, but I can follow your steps. I really appreciate you taking the time to explain it.

Many people edit the title screen (where it says "Start Game"). They may add there own name or something like that. Did they actually go through all those

steps to determine the address that needed to be changed?

You (I mean specifically you) make it sound so easy when someone asks for an address or offset and you come up with it in about 2 seconds.

I suppose that is just your experience, but it really is incredible.

Thanks again.

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  • 3 weeks later...
Ok, that is a little over my head, but I can follow your steps. I really appreciate you taking the time to explain it.

Many people edit the title screen (where it says "Start Game"). They may add there own name or something like that. Did they actually go through all those

steps to determine the address that needed to be changed?

You (I mean specifically you) make it sound so easy when someone asks for an address or offset and you come up with it in about 2 seconds.

I suppose that is just your experience, but it really is incredible.

Thanks again.

If your looking to add your name like where it normally says tecmo just get the latest version of TSB Manager and you can do it via that also.

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