GameHacking.org Weekly Hacking Target (06-12-11) - The Legend of Zelda [NES]

[BeyondTheStatic]

Thank you. The above set interferes with the minotaurs' swords (image-wise only), but should still work with a real NES system. The below set is worth the extra trouble, IMO.

[OldSchoolGamer]

Who is minotaur? The Knight looking enemies that are in the dungeons (The enemies that you have to hit from the back or the side)?

[BeyondTheStatic]

Um, I had to look it up: http://www.zeldadungeon.net/Zelda01-...nemy-guide.php It's called a Lynel.

[BeyondTheStatic]

OK, here's another one:

Remote Control Boomerang
EIVYUZUP
NYVYKXXN
SXSYENNY
EOSYONNN
IESYXNNY
XNSYUNNN
SESYKNNY
NXSYSNNY
AXSYVNNY
UOSYNNNY
XNSNENNN
AVSNONNY
[B]NOTE: Use the D-pad to control the boomerang mid-flight. When it hits an enemy or the edge of the screen, it will come back to you. Best when used with the magic boomerang.[/B]

All 12 codes are completely necessary, since the basic solution was messing with enemies' projectiles (among other things). In case anyone is wondering how it was done, the following is a quick rundown.

I discovered the boomerang's movement routine and found a good entry point here:

FA62:20 93 FA  JSR $FA93

I changed the JSR address to a point in freespace (one that is compatible with the sword cheats):

FA63=D0 // reroute the JSR operation to $FFD0
FA64=FF

Then I wrote a new routine like so:

FFD0=A5 // load $0098 (Link's facing direction) into the accumulator
FFD1=98
FFD2=05 // perform an ORA operation with $00FA (button press)
FFD3=FA
FFD4=85 // store accumulator to $00A7 (the boomerang's directional movement state)
FFD5=A7
FFD6=20 // jump to $FA93, which is where the hijacked JSR command was originally jumping to
FFD7=93
FFD8=FA
FFD9=60 // return from subroutine

The ORA operation allows the boomerang to be controlled diagonally, because $00FA can hold multiple button presses. Using a similar technique, it should be possible to allow Link himself to move diagonally, which could make for a nice game enhancement

Now all that is needed is to give the boomerang killing power, but I'm not sure how to approach that yet...

[Lazy Bastard]

Wow, that's an awesome code. Well done, man.

[BeyondTheStatic]

Thanks! Such a high number of codes is excessive, but I'm still learning. I never was able to allow Link to move diagonally, or to make the boomerang into an instrument of death...

Oh yeah, will all of the findings here be added to the database, or do I need to make a post to LG&RH?

[OldSchoolGamer]

No, you do not need to make another thread for these codes. The codes you posted in this thread will be added to the code database.

That would be sick if you somehow figured out how to make a game genie code that allowed Link to move diagonally.

[BeyondTheStatic]

Ah, OK, TY.

About that diagonal movement... allowing Link to move diagonally won't be as easy as it was for the boomerang, as the latter was meant to have eight degrees of movement to begin with. I might try to tackle the problem again when I've learned some more...

[nuomega457]

Thanks! Such a high number of codes is excessive, but I'm still learning. I never was able to allow Link to move diagonally, or to make the boomerang into an instrument of death...

Oh yeah, will all of the findings here be added to the database, or do I need to make a post to LG&RH?

Hi BeyondTheStatic. I may have found something that might help you make link move diagonally. I was playing around with these two hex addresses.

7127 and F494

I changed them to:
7127:8D
F494:85

It is very glitchy and link is very messed up, weapon behavior is messed up besides a host of other things, but when you shoot your sword, if you try to move around, it appears he moves diagonally in some cases?

Hope this helps! :-)

[BeyondTheStatic]

Hi BeyondTheStatic. I may have found something that might help you make link move diagonally. I was playing around with these two hex addresses.

7127

That one controls the sword beam state, also the subweapons (which you already knew )

and F494

This seems to control how Link moves after using a weapon, but I'm not sure.

An important address to consider is this one:

03F8: Link's walking state

=01: right
=02: left
=04: down
=08: up

A write breakpoint snaps to EC5F, and right above it is the code that loads from 00FA, the controller state. You can make Link auto-walk in a specific direction by doing this:

EC5B=A9 // load a value (not an address)
EC5C=02 // make him walk left

which doesn't help much, because Link was only meant to walk in the four cardinal directions. I don't know what it will take, but maybe code can be borrowed from the boomerang or something. By the time it's done (if it ever is), it might be waaay too many codes. Nestopia's cheat import feature works well for those cases.

[Helder]

Why even bother? just make a rom patch ips file and distribute it, less codes to post or worry about.

[BeyondTheStatic]

Yeah, that's a good idea (assuming I ever find out how to enable diagonal movements). I would have to include the remote control cheats too, of course

[BeyondTheStatic]

I think I discovered something. While looking for a fairy always appear on any board you are on, I found this.
...
Now, when I use 35, a pattern of coins appears and you can keep collecting them and they reappear.

Isn't this weird?

That's pretty cool, Nuomega. I noticed that you can take all but the top rupy, at which point the array will replenish itself. It got me to thinking about how to force enemies to drop specific items. The first thing I found was that all enemies have a timer that controls whether or not they drop an item:

0018: counter to determine when an enemy will drop an item (every enemy has its own timer, but this is the master address)

So, to make sure they always drop an item, you can do this:
E546=95

or

Enemies Always Drop an Item
SPKTTISL
[B]NOTE: This will mess with enemy movement patterns.[/B]

There's probably a more optimal solution, but I haven't found it yet.

The next thing was to check which items they dropped. I spent a long time trying to track down all the conditions, and became quite confused. Luckily, I recently learned how to load a value (not just an address) into the accumulator, and finally found the codes that will force an enemy to drop a specific item at just the right moment:

Enemy Drop Item Modifier
B0E9=A9
B0EA=??
	=00: bomb
	=01: wooden sword
	=02: white sword
	=03: magical sword
	=04: food
	=05: recorder
	=06: blue candle
	=07: red candle
	=08: arrows
	=09: silver arrow
	=0A: bow
	=0B: magical key
	=0C: raft
	=0D: stepladder
	=0E: ??
	=0F: 5 rupies
	=10: magical rod
	=11: book of magic
	=12: blue ring
	=13: red ring
	=14: power bracelet
	=15: letter
	=16: compass
	=17: map
	=18: 1 rupy
	=19: key
	=1A: heart container
	=1B: triforce piece (doesn't seem to add to final triforce)
	=1C: magical shield
	=1D: boomerang
	=1E: magical boomerang
	=1F: life potion
	=20: 2nd potion
	=21: clock
	=22: heart
	=23: fairy
	=24: fairy (immobile)

You can actually collect and keep them All things after 24 seem to be nonsense items, such as bombs that decrease your stash among other weird things.

As a generic Game Genie cheat it looks like this:

Enemy Drop Item Modifier
OXVUPASX
??VUZAA?
[B]NOTE: Replace "?" with the appropriate characters (requires some Game Genie encoding knowledge). All values between 00-24 (hex) are good.[/B]

And an example:

Enemies Only Drop Bombs
OXVUPASX
AEVUZAAA
[B]NOTE: See the enemy drop modifier code to make them drop the item of your choosing.[/B]

To make only one enemy drop a specific item (like a fairy) might be difficult, and would most likely require the creation of several codes.

[Lazy Bastard]

Hey, that's another really cool code. There have been quite few innovative ideas during the last few hacking targets.

[BeyondTheStatic]

Good thing hacking targets can last more than a week