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’Cause all games were better on the GBC

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#1 2013-05-17 00:30:10

FroggestSpirit
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Registered: 2012-03-12
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Practical use of the 8th Floor Item

http://www.youtube.com/watch?v=bP00FPrvPRU
A glitch that has nearly infinite potential

Here is a save for a built in gameshark I wrote
https://anonfiles.com/file/27140376fe79 … 2859369281

Last edited by FroggestSpirit (2013-05-18 15:46:36)


This isn't easy to say, but…
Music and ASM hacker

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#2 2013-05-17 04:30:58

Miksy91
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Registered: 2010-10-16
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Re: Practical use of the 8th Floor Item

That's really cool!
I personally had never heard of this "8F", nor it actually "working".

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#3 2013-05-17 12:06:51

FroggestSpirit
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Re: Practical use of the 8th Floor Item

I never heard of it till yesterday. It jumps the code to the address where it tells you how many pokemon are in your party, so if you get the right party, it will bootstrap the code to your item bag. from there, it's easier to manipulate.


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#4 2013-05-17 14:53:23

80C
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Registered: 2013-03-16
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Re: Practical use of the 8th Floor Item

I've got a glitch that changes the music of a map too.
I discovered it when I was trying add pokemon #252.

If you add the Data, cry, pic of a Pokemon but not the pokedex pages, and if you're playing in a pokecenter, when you load the Pokedex page 252 (if you have at least seen #252), the pokemon plays strange cryes, probabilly interfered with game data so the game interpretates the data as cries, then - only in pokecenter - the music changes to vermillion city music, if you're in other places, the game freezes.

Anyway I didn't noticed of 8F, I noticed only of ??????(Surfboard), another ????(Jump! sometimes it made me fly), boulderbadge, cascadebadge and another F object that has a very weird effect when used during wild battles.


I left this forum.

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#5 2013-05-18 15:47:42

FroggestSpirit
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Re: Practical use of the 8th Floor Item

I just finished up a portable gameshark! Now you can modify values of the RAM on the fly. I used it to beat the game, and change the current playing music. It could also be used to write a custom ASM routine in RAM


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Music and ASM hacker

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#6 2013-05-18 19:57:16

80C
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Re: Practical use of the 8th Floor Item

@FroggestSpirit

your hacking skills are amazing.
Another one time - after the colored red - you left me stunned.
So, you're able by 8F and gameshark to build custom routines IN-GAME!!!???
Even on phisical cartridge???

Uh, another one thing, could you explain how to use 8F, because most of the times it glitches, so, in which conditions it could work?

PS: I found another funny object, 1F.
It plays the animation of pokeball and a prize music OUTSIDE battles, glitching up the tiles, but it never catches pokemon.
I dunno how it could help but maybe it could have a role too...


I left this forum.

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#7 2013-05-19 13:52:26

FroggestSpirit
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Re: Practical use of the 8th Floor Item

Things you dont want to mess with:
Your party's first 4 pokemon (though you need to have 6 pokemon in it)
The item storage in the pc
the box 1 in the pc. Idk what changing boxes will do, but if box 1 isnt the current box, it wont work.

The 8F item jumps the code, so it reads from the address of your party. Using specific pokemon, I jump it to the PC item storage. There starts the code for the built in RAM editor. That wasn't enough space though, so I had to jump the rest of it to Box 1.

You can do misc thing with this, like for walk through walls, type CD3801, press start. to turn it off, enter CD3800 and press start.
It has it's limitations as stated above, but still fun to mess around with


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#8 2013-05-20 13:43:21

Torchickens
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Registered: 2011-01-02
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Re: Practical use of the 8th Floor Item

8F has essentially the same function of 5かい (5F) (hex:5A) in Pocket Monsters Red and Green (more information about 5かい can be found here). I first read about 5かい on the Japanese glitch website kattempla/pokebug. Somebody by the name of k)ry set their own requirements for several cheats, like encountering any Pokémon based on the quantity of item 1 (video: here), as well as a custom debug menu (though the debug menu is impossible to set up without cheating).

5かい runs machine code beginning from WRA1:D123 (Number of Pokémon). When someone asked me on the GCL forums if there was an easy way to obtain 5かい, I found that you could swap the ninth item with the first Pokémon to corrupt your number of items (the number of items you get depends on the Pokémon's defence exp byte 2, D141) and then go to this spot on Cycling Road. This makes D2E0 (y-coordinate) = 5Ah, so it appears as the 32nd item in the bag.

jKgbB8CHN7Fhy.png

Later, I used it to do a linked "catch 'em all run" of Pocket Monsters Green, using k)ry's bootstrap code that jumps to D2A4; the second item and 'catch 'em all' code, that writes to D036 (encounter any Pokémon) based on the quantity of item 1.

Bootstrap code:

1) 06h: 6 Pokémon (0xD123)
2) xxh: Any first Pokémon (0xD124)
3) 18h: Tentacool as the second Pokémon (0xD125)
4) 4Dh: Meowth as the third Pokémon (0xD126)
5) 18h: 24 PP left on the second Pokémon's first move (0xD174)
6) 56h: 22 PP left on the second Pokémon's second move w/ 1 PP Up used (0xD175)
7) 18h: 24 PP left on the 4th Pokémon's first move (0xD1CC)
8) 56h: 22 PP left on the 4th Pokémon's second move w/ 1 PP Up used (0xD1CD)
9) 18h: 24 PP left on the 6th Pokémon's first move (0xD224)
10) 4Fh: 15 PP left on the 6th Pokémon's second move w/ 1 PP Up used (0xD225)
11) C3h, A4h, D2h: The 6th Pokémon's nickname begins with "てヨめ" (0xD275-0xD277)

ASM:

D123 06 xx   ;ld B,xx
D125 18 4D   ;jr D174

D174 18 56   ;jr D1CC
D1CC 18 56   ;jr D224
D224 18 4F   ;jr D275

D275 C3 A4 D2    ;jp D2A4

Catch 'em all code:

12) FAh: The second item is TM50 (0xD2A4)
13) A3h: The second item quantity is 163 (0xD2A5)
14) D2h: The third item is TM10 (0xD2A6)
15) EAh: The third item quantity is 234 (0xD2A7)
16) 36h: The fourth item is Max Revive (0xD2A8)
17) D0h: The fourth item quantity is 208 (0xD2A9)
18) C9h: The fifth item is TM01 (0xD2AA)


ASM:

D2A4 FA A3 D2    ;ld A,(D2A3) D2A3,道具1番目の個数です。
D2A7 EA 36 D0    ;ld (D036),A それを出現するポケモンに対応させます。
D2AA C9        ;ret

TheZZAZZGlitch later made the discovery that the English Red/Blue's 8F (hex: 5D) runs machine code beginning from D163 (Number of Pokémon), just like the Japanese 5かい!

Obtaining 8F:

You can obtain it with any name using this glitch, or this (much easier) glitch, which involves battling Rocket roster 28h with a name containing 'MN' as the 3rd, 5th or 7th character, then doing the Old Man glitch to encounter Prof Oak roster 28h, then beat his team until he sends out 94 (hex: F1 glitch Pokémon).

Each glitch requires a Good Rod (4Dh) in the fourth position, to turn it into 8F (5Dh) upon encountering/capturing 94. The reason that works is because 94 is #213. It has an invalid encounter flag which adds 16 (10h) to the identifier of the fourth slot in the player's bag if the item does not have one of the following hexadecimal identifiers: $1X $3X $5X $7X $9X $BX $DX $FX.


Applications:

A number of applications for 8F with requirements can be found in this thread. Also, here is a link to a video of an application that lets you write and execute up to 254 byte programs.

TheZZAZZGlitch wrote a bootstrap program to jump to the third item. It can be found in the aforementioned thread.

A similar glitch item in Yellow is "ws m" (hex:63h), which reads from DA7F, the number of Pokémon in the current box. You can obtain it by doing the Ditto glitch with a Special stat of 194 to encounter p PkMn p' ' with an X Speed in the fifth position (43h) in the fifth position. Encountering p PkMn p' ' will add 32 to the identifier of the fifth slot in bag if the item does not have one of the following hexadecimal identifiers: $2X $3X $6X $7X $AX $BX $EX $FX, so 43h changes into 63h.

The bootrapping code for "ws m" written by TheZZAZZGlitch to jump to the third item can be found here.

Last edited by Torchickens (2013-05-20 14:06:25)

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#9 2013-05-20 15:36:30

YORAMRW
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Re: Practical use of the 8th Floor Item

@FroggestSprit
Could you share the ROM with the BW Rival music with us. It sounds really cool.


Hacks Gameboy 8-bit music in Pokémon Gen I & II, composes 8-bit music in FamiTracker

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#10 2013-05-22 18:47:38

FroggestSpirit
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Re: Practical use of the 8th Floor Item

That wasnt a rom, that was the actual game with a hacked save file (which i no longer have the save file, except on the cart)


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Music and ASM hacker

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#11 2013-05-22 19:40:15

YORAMRW
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From: The Netherlands
Registered: 2013-03-29
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Re: Practical use of the 8th Floor Item

FroggestSpirit wrote:

That wasnt a rom, that was the actual game with a hacked save file (which i no longer have the save file, except on the cart)

Please try to dump it from the cart, could you?
Or don't you have a cardreader?
Please tell me, so I can take into account whether you will do or don't.

Last edited by YORAMRW (2013-05-22 19:42:44)


Hacks Gameboy 8-bit music in Pokémon Gen I & II, composes 8-bit music in FamiTracker

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#12 2013-05-24 12:59:07

FroggestSpirit
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Registered: 2012-03-12
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Re: Practical use of the 8th Floor Item

The way I transfered my saves are as follows (because of a lack of other methods)
-Burn rom and save to GBC flashcart
-Load with GBC Gameshark
-Savestate in middle of game
-Load real cart with gameshark
-restore savestate
-save game, and boom, done.
Unfotunately, this wont save data from A000-BFFF


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Music and ASM hacker

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