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Author Topic: Need help with zelda 2 hacking  (Read 1979 times)

duke24e

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Need help with zelda 2 hacking
« on: September 03, 2019, 09:54:35 am »
Hi guys,

I need help with my project, I checked utilities to edit zelda 2 but I just dont figure out how to do this.

NOTE: If someone have good knowledge of hacking zelda2 or asm hacking, I can offer to pay for his time and I will update this post how the hack for each modification can be done to share it with others.

here is what I would like to edit:
1. replace the sound when Link walking on the overworld map when he encounter random scenes. I would like another sound. The current sound is just too noisy.

2. It is possible to add more mini boss in palace ?
Note: Yes, after my research, using z2edit editor and the boss have to be on the 3rd frame. I try to add a mini boss into 1st, 2nd and 4th frame and it give unexpecting results, I dont know why, on 1st and 4th frame, the mini boss fight start when link arrive without seeing the mini boss (the fight start while link is on the 3rd frame and the boss is on the 4th frame) and the mini boss walk to you and appear on screen where you are, once defeated, it drop a key and after taking the key, it respawn again another fight begin, and it respawn again and again, I dont know why it is like that ?

If the mini boss is put on the 3rd frame, the fight start normally, link have to walk very near to the mini boss before the fight begin (just like any boss fight) and once defeated it drop a key and after taking the key, link can continue exploring the palace normally.

if the mini boss it put on 1st frame, the mini boss act like a statue and staying there, no fight is engage.

What I would like to do:
2.1. add a mini boss that is on another overwrold (example: adding a boss from east hyrule into west hyrule) so I dont know at this point how to put helmethead boss from palace2 as a mini boss into palace 5 because the sprite is replaced with gooma. Someone know a workaround ? I would like to keep gooma as final boss and put helmethead as a mini boss in palace 5.

2.2. add a mini boss on any palace with the life point vertical bar, example: add a blue knight as a mini boss into palace 4

2.3. add a a mini boss with new graphics of a new enemy ?


3. add 2-3 scenes for the long bridge before the island maze, instead of cross the bridge without any challenges.

4. add 2-3 scenes for the entrance of death mountain and when exiting the death mountain.

5. I would like to fix the shadow link weakness, in the usa version we just need to stay of left side of the screen and keep slaying.
Note: ASM hack maybe ? anyone know how to fix that glitch ? I could fix it by placing a lava pit on the left corner of the screen but I would like to fix the glitch..

6. I would like some spell like shield and reflect to stay when changing scene, the effect would go off only if link die or go outside.

7. add more towns and palace without boss and crystals.

8. can we add more areas ? or if the numbers of areas are hardcoded in the game ?

9. One question about rom expansion, doc I just read to expand the rom of zelda 2. What is the utility fo expanding the rom ? does that mean we can add more town, palace or expand the over world map ?

10. There is a way to hack thunderbird to be a more tough challenge ? I would like to make the reflect spell ineffective against him, in the z2edit editor there is some attributes "unknown", someone have an idea ? and I would like to change his fireball angles to cover more range, that will increase his difficulty :)

11. with z2edit I can change the palette of palaces, the problem I have with that, the falling block generator is keeping another color while falling, once the block hit the ground it take the new color of the ground of the palace. Doe anyone know where to change the color of the falling block for each palace ?

12. I would like to add more challenge for the wizard boss of palace 4. Once we have the reflect spell is jus too easy, staying on the corner and wait to reflect his projectile against him. I would like to keep the reflect spell utility for link but not hurt the Wizard back. It is possible ?

new idea: I would like the reflect spell make link able to use his sword against this boss, since he is teleport himself across the screen it would be a good challenge but I would like to make it only be hit on a particular spot like the thunderbird. So basically the reflect spell will act like thunder spell for thunderbird. just make it able to hit the boss. But the reflect spell will still protect link but not hit the boss wizard.

13. I would like to change the palace 6 to palace 7, instead of having the palace 6 appear when playing flute between rocks I would like to enter palace 7 and place the palace 6 non hidden where palace 7 is. I dont know how to do this. I was able to make link enter palace 7 but the graphic is horrible and when I exit, I am in the middle of ocean.

14. I would like to make some monsters more agressive and faster, like the blue bots. jumping higher and faster.

15. I would like to make the containers, hearts and magic to be discover only if link talking to someone particular in town or on certain conditions, so if link enter the cave where a container is without talking to that guy or without the condition it would be just a dead end.

16. I would like to make the town tile animated with chimney smoking.

17. Change the palace rock with a scene with 3-4 frames with rumble rock and couple of invisible moats floating and changing the tile to look like a damaged palace.

18. remove somes keys in palace and put a guy in each town that can give keys to link on certain conditions, if link die (game over) in the palace he will loose all his keys.

19. Have enemies in palace drop keys sometimes.

20. I would like to make link can walk over any water tiles when he have boots but it get stuck because of limited screen, can we add endless ocean ?

21. make the wise man in each town giving you the new spell only if you have enough experience.

22. Make boss of palace 6 immune to sword down attack

23. Make boss of palace 6 spit fire on different angle and mutiple time on each attack.

24. If link walk on lava tile overworld he will loose life if he doesnt have the boots and he will move slowly.

25. Changing somes graphics, but I dont know which tool to use..all the editor for nes I try showing the sprites into 8x8 or 16x8 with the wrong color.

26. I would like to let link going on second overworld without the raft, like adding a cavern with many difficult scenes, using the raft would be a shortcut only.

27. There is something I like a lot when playing zelda 1 (the first zelda on nes, its not a typo lol)

it is the player can explore almost 95% of the overworld without progress in the game and you realize you must complete palace and find items to going into more dangerous zone.

with zelda 2, its more like a straight path, you cant go on overworld 2 without the raft and you cant go into palace3 if you dont have the hammer..
on the overworld 2 you have to do the 4th palace before going on palace 5 and you cant go south before getting the flute on palace5.

Thats why Im looking for theses modifications to bring the exploring possibility to another level:
1. remove the roadblock before path leading to the town beside the palace3.
2. add a cavern with strong enemies and the exit would be on the overworld 2, it is supposed to be very hard to going on this new cave to not making the raft useless, because the raft will act as a shortcut once you get it.
3. same thing to the overworld 2, adding a very hard challenging cave to go south without having to have the flute. The flute will act as a shortcut to going to south once you get it.

4. moving somes items locations:
candle: palace1 (no changes)
glove: palace2 (no changes)
raft: palace4 (so you have to pass the new cave before getting it and the player have to explore overworld 2)
boots: death mountain
hammer: palace3
flute: dead kasuto
magic key: place it in a forest somewhere in north of overworld 2 to be discovered only if you chop the right trees with the hammer.
cross: palace6 (no change)


thanks for your help :)
« Last Edit: September 15, 2019, 12:08:12 am by duke24e »

KingMike

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Re: Need help with zelda 2 hacking
« Reply #1 on: September 03, 2019, 01:20:52 pm »
Without any information on what "your project" is and already has been done, I have to move this to a different forum.
"My watch says 30 chickens" Google, 2018

Psyklax

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Re: Need help with zelda 2 hacking
« Reply #2 on: September 04, 2019, 01:12:30 am »
Let me address your points:

1. On the NES, sound and music are the same because they're all generated by the sound chip, and changing anything with the sound is definitely not a task for a newcomer, let's put it that way.

2. That's certainly doable, though again, unless there's a specific tool to help you, you'll need to get into the assembly and find out where the game stores the level data, then modify it. With some help, it shouldn't be too hard.

3. Possible, but more difficult since it involves adding stuff to the level data rather than replacing something (maybe, I haven't looked at the data).

So points 2 and 3 are not too tricky, but point 1 is probably more trouble than it's worth.

duke24e

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Re: Need help with zelda 2 hacking
« Reply #3 on: September 04, 2019, 09:15:10 am »
Let me address your points:

1. On the NES, sound and music are the same because they're all generated by the sound chip, and changing anything with the sound is definitely not a task for a newcomer, let's put it that way.

2. That's certainly doable, though again, unless there's a specific tool to help you, you'll need to get into the assembly and find out where the game stores the level data, then modify it. With some help, it shouldn't be too hard.

3. Possible, but more difficult since it involves adding stuff to the level data rather than replacing something (maybe, I haven't looked at the data).

So points 2 and 3 are not too tricky, but point 1 is probably more trouble than it's worth.

thanks for you reply, very appreciated. I just try a scene editor and after a couple of tests, it seem difficult because all the graphics was a mess but it look nice in the editor ? I surely done something wrong but I dont know what.

There is a way to test our modifications on the spot ? I mean if I try to replace the mini boss in the 5th palace I dont want to play all the game to test it lol

4l3j4ndr0

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Re: Need help with zelda 2 hacking
« Reply #4 on: September 04, 2019, 02:49:27 pm »
Code: [Select]
There is a way to test our modifications on the spot ? I mean if I try to replace the mini boss in the 5th palace I dont want to play all the game to test it lol
You have to find a save file for this stage, maybe someone post it on internet.
Otherwise you have to reach that level and make a save file, then load it everytime you made a change on that screen.

Sometimes you can use gamesharks to teleport between maps but isn't simple as get in there. Sometimes you need to defeat and win some previous bosses to be able to defeat the main boss.

duke24e

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Re: Need help with zelda 2 hacking
« Reply #5 on: September 04, 2019, 03:10:20 pm »
Code: [Select]
There is a way to test our modifications on the spot ? I mean if I try to replace the mini boss in the 5th palace I dont want to play all the game to test it lol
You have to find a save file for this stage, maybe someone post it on internet.
Otherwise you have to reach that level and make a save file, then load it everytime you made a change on that screen.

Sometimes you can use gamesharks to teleport between maps but isn't simple as get in there. Sometimes you need to defeat and win some previous bosses to be able to defeat the main boss.

Yes, I think I will play the whole game and save regular states a different points of the game :) so the save state is independent of the rom ?

Psyklax

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Re: Need help with zelda 2 hacking
« Reply #6 on: September 05, 2019, 04:12:29 am »
if I try to replace the mini boss in the 5th palace I dont want to play all the game to test it lol

Tough luck. :D You'll need to get to the point in the game where you want to make changes, otherwise how are you going to know what to change? You can use cheats, of course. Besides, Zelda 2 is awesome so playing through it wouldn't be so bad. :)

I just looked at your original post again and I see you've edited it to add a whole load of new stuff. I would just say that if you don't know anything about assembly, you'll need to get started if you want to do most of that stuff. ;)

Out of curiosity, I had a look myself - only at your second point, since that's by far the easiest. Data Crystal has lots of stuff about the RAM and ROM maps of Zelda 2, so after checking that out, I had a go.

I entered an enemy encounter, and saw that the enemy IDs are loaded into work RAM around $A2. I changed the 05 there to 06 and a totally different enemy appeared. Cool! So the question then was where did the game get this 05 from. I set a write breakpoint for $A2 when I entered the encounter and it came from $70C0 in the SRAM, where the game keeps enemy data. Of course, it got into the SRAM from the ROM, so I reset the game and found where $70C0 got loaded from. Answer: $8960. So the 85 there has the top four bits removed to leave 05, which is then placed in the work RAM for the encounter. So changing it to 86 gives us one of those flying eye things instead. Success! :)

Now you just have to play through the game to the point where this boss shows up and find out the SRAM location for his enemy ID, then find where in ROM that came from, then change it. Simple. Only question is: can you even use the enemy you want there? Not all enemies in the game are possible to use in every part, they're divided into chunks.

After some research, I think it's possible, because the enemy you face in the FDS version is Horsehead, who is the boss of the FIRST palace. You confused me by saying it was the boss of the second palace. :) I'll play with some RAM values to warp across the map and go into the dungeon to see if I can get there quickly.

EDIT: well that was interesting. :) I warped myself to the palace and cheated my way through it, but when I changed the blue knight to the Horsehead, it worked, sort of... but the graphics were all messed up, and it was stuck in the floor. I guess changing the Y position would fix the latter problem, but the messed-up graphics are probably because the Horsehead graphics aren't loaded into VRAM at that point. Fixing that would be a hell of a task. This is as far as I go, I'm afraid. :D
« Last Edit: September 05, 2019, 04:37:10 am by Psyklax »

duke24e

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Re: Need help with zelda 2 hacking
« Reply #7 on: September 05, 2019, 10:01:12 am »
Tough luck. :D You'll need to get to the point in the game where you want to make changes, otherwise how are you going to know what to change? You can use cheats, of course. Besides, Zelda 2 is awesome so playing through it wouldn't be so bad. :)

I just looked at your original post again and I see you've edited it to add a whole load of new stuff. I would just say that if you don't know anything about assembly, you'll need to get started if you want to do most of that stuff. ;)

Out of curiosity, I had a look myself - only at your second point, since that's by far the easiest. Data Crystal has lots of stuff about the RAM and ROM maps of Zelda 2, so after checking that out, I had a go.

I entered an enemy encounter, and saw that the enemy IDs are loaded into work RAM around $A2. I changed the 05 there to 06 and a totally different enemy appeared. Cool! So the question then was where did the game get this 05 from. I set a write breakpoint for $A2 when I entered the encounter and it came from $70C0 in the SRAM, where the game keeps enemy data. Of course, it got into the SRAM from the ROM, so I reset the game and found where $70C0 got loaded from. Answer: $8960. So the 85 there has the top four bits removed to leave 05, which is then placed in the work RAM for the encounter. So changing it to 86 gives us one of those flying eye things instead. Success! :)

Now you just have to play through the game to the point where this boss shows up and find out the SRAM location for his enemy ID, then find where in ROM that came from, then change it. Simple. Only question is: can you even use the enemy you want there? Not all enemies in the game are possible to use in every part, they're divided into chunks.

After some research, I think it's possible, because the enemy you face in the FDS version is Horsehead, who is the boss of the FIRST palace. You confused me by saying it was the boss of the second palace. :) I'll play with some RAM values to warp across the map and go into the dungeon to see if I can get there quickly.

EDIT: well that was interesting. :) I warped myself to the palace and cheated my way through it, but when I changed the blue knight to the Horsehead, it worked, sort of... but the graphics were all messed up, and it was stuck in the floor. I guess changing the Y position would fix the latter problem, but the messed-up graphics are probably because the Horsehead graphics aren't loaded into VRAM at that point. Fixing that would be a hell of a task. This is as far as I go, I'm afraid. :D

Nice, thank for your help, I will take a look. I just found another editor z2edit on github, it is very nice with many possibilities. But I cannot change the mini boss to whatever I want, I am limited, I think you are right, in the editor there is address to point to a enemy table set, I think I just have to edit that. But I dont know where to change it in the rom.

For the tests purpose I am currently playing normally all of the game to the end and save states regularly, if you need states I can share it :)

September 05, 2019, 01:38:16 pm - (Auto Merged - Double Posts are not allowed before 7 days.)
Tough luck. :D You'll need to get to the point in the game where you want to make changes, otherwise how are you going to know what to change? You can use cheats, of course. Besides, Zelda 2 is awesome so playing through it wouldn't be so bad. :)

I just looked at your original post again and I see you've edited it to add a whole load of new stuff. I would just say that if you don't know anything about assembly, you'll need to get started if you want to do most of that stuff. ;)

Out of curiosity, I had a look myself - only at your second point, since that's by far the easiest. Data Crystal has lots of stuff about the RAM and ROM maps of Zelda 2, so after checking that out, I had a go.

I entered an enemy encounter, and saw that the enemy IDs are loaded into work RAM around $A2. I changed the 05 there to 06 and a totally different enemy appeared. Cool! So the question then was where did the game get this 05 from. I set a write breakpoint for $A2 when I entered the encounter and it came from $70C0 in the SRAM, where the game keeps enemy data. Of course, it got into the SRAM from the ROM, so I reset the game and found where $70C0 got loaded from. Answer: $8960. So the 85 there has the top four bits removed to leave 05, which is then placed in the work RAM for the encounter. So changing it to 86 gives us one of those flying eye things instead. Success! :)

Now you just have to play through the game to the point where this boss shows up and find out the SRAM location for his enemy ID, then find where in ROM that came from, then change it. Simple. Only question is: can you even use the enemy you want there? Not all enemies in the game are possible to use in every part, they're divided into chunks.

After some research, I think it's possible, because the enemy you face in the FDS version is Horsehead, who is the boss of the FIRST palace. You confused me by saying it was the boss of the second palace. :) I'll play with some RAM values to warp across the map and go into the dungeon to see if I can get there quickly.

EDIT: well that was interesting. :) I warped myself to the palace and cheated my way through it, but when I changed the blue knight to the Horsehead, it worked, sort of... but the graphics were all messed up, and it was stuck in the floor. I guess changing the Y position would fix the latter problem, but the messed-up graphics are probably because the Horsehead graphics aren't loaded into VRAM at that point. Fixing that would be a hell of a task. This is as far as I go, I'm afraid. :D

I just finished somes tests. with zelda 2 side view editor I was able to change the address of enemy list on one scene into palace 1 and now the final boss of 2nd palace appear in palace 1, I can fight it, it work well, the color is perfect but the sprite and his life bar flickering ? I dont know why ? it flicker every seconds ? any idea ? And when I kill it, a key falling from sky, I got XP and I have to fight it again and again and again, like it respawn every time I dont know why ?

September 11, 2019, 04:04:33 pm - (Auto Merged - Double Posts are not allowed before 7 days.)
Hi guys,

I need help with my project, I checked utilities to edit zelda 2 but I just dont figure out how to do this.

NOTE: If someone have good knowledge of hacking zelda2 or asm hacking, I can offer to pay for his time and I will update this post how the hack for each modification can be done to share it with others.

here is what I would like to edit:
1. replace the sound when Link walking on the overworld map when he encounter random scenes. I would like another sound.

2. It is possible to add more mini boss in palace ?
Note: Yes, after my research, using z2edit editor and the boss have to be on the 3rd frame. I try to add a mini boss into 1st, 2nd and 4th frame and it give unexacting results, I dont know why, on 1st and 4th frame, the mini boss fight start when link arrive without seeing the mini boss and the mini boss walk to you and appear on screen where you are, once defeated, it drop a key and after taking the key, it respawn again another fight begin, and it respawn again and again, I dont know why it is like that ?

If the mini boss is put on the 3rd frame, the fight start normally, link have to walk very near to the mini boss before the fight begin (just like any boss fight) and once defeated it drop a key and after taking the key, link can continue exploring the palace normally.

if the mini boss it put on 1st frame, the mini boss act like a statue and staying there, no fight is engage.

What I would like to do:
1. add more mini boss in palaces without dropping a key once he is defeated if its possible.
2. add a mini boss that is on another overwrold (example: adding a boss from east hyrule into west hyrule) so I dont know at this point how to put helmet head mini boss into palace 5 because the sprite is replaced with gooma. Someone know a workaround ? I would like to keep gooma as final boss and put helmet head as a mini boss in palace 5.


3. add 2-3 scenes for the long bridge before the island maze, instead of cross the bridge without any challenges.

4. add 2-3 scenes for the entrance of death mountain and when exiting the death mountain.

5. I would like to fix the shadow link weakness, in the usa version we just need to stay of left side of the screen and keep slaying.
Note: ASM hack maybe ? anyone know how to fix that glitch ? I could fix it by placing a lava pit on the left corner of the screen but I would like to fix the glitch..

6. I would like some spell like shield and reflect to stay when changing scene, the effect would go off only if link die or go outside.

7. add more towns and palace without boss and crystals.

8. can we add more areas ? or if the numbers of areas are hardcoded in the game ?

9. One question about rom expansion, doc I just read to expand the rom of zelda 2. What is the utility fo expanding the rom ? does that mean we can add more town, palace or expand the over world map ?

10. There is a way to hack thunderbird to be a more tough challenge ? I would like to make the reflect spell ineffective against him, in the z2edit editor there is some attributes "unknown", someone have an idea ?

11. with z2edit I can change the palette of palaces, the problem I have with that, the falling block generator is keeping another color while falling, once the block hit the ground it take the new color of the ground of the palace. Doe anyone know where to change the color of the falling block for each palace ?

12. I would like to add more challenge for the wizard boss of palace 4. Once we have the reflect spell is jus too easy, staying on the corner and wait to reflect his projectile against him. I would like to keep the reflect spell utility for link but not hurt the Wizard back. It is possible ?

new idea: I would like the reflect spell make link able to use his sword against this boss, since he is teleport himself across the screen it would be a good challenge but I would like to make it only be hit on a particular spot like the thunderbird. So basically the reflect spell will act like thunder spell for thunderbird. just make it able to hit the boss. But the reflect spell will still protect link but not hit the boss wizard.

13. I would like to change the palace 6 to palace 7, instead of having the palace 6 appear when playing flute between rocks I would like to enter palace 7 and place the palace 6 non hidden where palace 7 is. I dont know how to do this. I was able to make link enter palace 7 but the graphic is horrible and when I exit, I am in the middle of ocean.

14. I would like to make some monsters more agressive and faster, like the blue bots. jumping higher and faster.

15. I would like to make the containers, hearts and magic to be discover only if link talking to someone particular in town, so if link enter the cave where a container is without talking to that guy, it would be just a dead end.

16. I would like to make the town tile animated with chimney smoking and change the palace rock with a scene with 3-4 frames with rumble rock and couple of moats floating.

17. remove somes keys in palace and put a guy in each town that can give keys to link, if link die (game over) in the palace he will loose all his keys.

thanks for your help :)
« Last Edit: September 11, 2019, 04:04:33 pm by duke24e »