Zelda II - Examples of ASM Hacking

This video shows many examples of ASM hacking on the NES game Zelda II: The Adventure of Link. All enemies were altered in some ways. Some modifications are simple variable tweaks, while others involve ASM code created from scratch and incorporated into the original code...

Enemies move faster, attack more often, projectiles have greater velocity, many aspects of enemy routines are more randomized...

Category:

Gaming

Tags:

• zelda
• zelda II
• adventure
• link
• asm
• hacking
• nes
• nintendo
• rom
• tweaks
• assembly
• assembler
• 6502

[theOriginalLink1]

how much 6502 assembly would it take to put the spin attack in the original zelda.nes?

[Simboiss]

@theOriginalLink1 I'm actually working on it. I already have a charged sword attack in the works that is almost free of glitches. The spin attack is something a lot more tricky. What makes things difficult is that the routines for Link's behavior are quite complicated. There's a lot of code and all the code must be mastered without fault.

Some of the states to be aware of:

- Is Link in mid-air? Going up or down?

- Is he ducked? In mid-air? After landing?

- Is he being hit?

Things like that...

[HoodwinkHighbrow]

Song please? This is pretty cool song.

[Simboiss]

The song is a remix of the Palace Theme, named Temple Trance, made by a guy nicknamed Blind. You can download the original music on ocremix . org .

[fpb221985]

so basically, you made the game harder by making things more random as apposed to them having a pattern? What did you use to decode the game if you don't mind me asking. I'm interested in reprogramming NES games, though I originally wanted to reprogram abandon ware games (because there's so many, and they're all free and small. Mostly.)

[Simboiss]

You need to learn 6502 (the processor of the NES) assembler and have a good knowledge of the game you want to hack, the ROM offsets for data tables and routines, the RAM offsets for variables, etc.

I made a program named Loch NES (Mac OS X only) that outputs disassembly of any NES ROM in text form. This makes the work a lot easier and more efficient.

There's also a lot of trial-and-error involved.

[mike478911]

I can just immagen the trial and error that when on....... oh GOD......... Nice job :)

[RuneLancer]

Ah, finally someone who's doing more work than just a few graphical hacks or tweaks through someone else's tools. Neat stuff. Though your hacks don't seem to involve rewriting much code, just changing some values so some mechanisms gets triggered faster... Still great though!

[DarknessSavior]

This is cool, but I'm of the opinion that Zelda II was hard enough already. =P

[geminimewtwo]

Fantastic! Maybe it looks a little too hard in some spots, but I really love most of the ideas you've implemented.