What is 8F?

8F is a Red/Blue equivalent of JP Red/Green’s item executing machine code starting from $D163 (Number of Pokemon) upon use. Its hex identifier is 0x5D, despite its hex-like name. 8F is treated by the game as a key item and it can’t be tossed away or sold in the mart.

As address $D163 contains re-writeable data, it is possible to redirect the instruction pointer to the item list with relative jumps and easily run arbitrary code just by spelling the opcodes with items. With enough items, one could also make a program that reads key input continuously, writes it somewhere in the RAM and jumps to it after a while, allowing to even run your own homebrew software.

How to Get 8F?

By Using Item Counter Underflow Glitch:


– Access to any event that removes an item from your inventory (Saffron guards, handing out a fossil in Cinnabar Lab, etc.)
– A following item list:
Any item x[Any qty]
X Special x255
Item you need to give away x1

If you don’t have access to any item-removing event, you can still do the “dry variation” of the glitch, by following the steps described here.


1. Toss the first item. It should change to X Special x255
2. Continue tossing the first item until the item menu “stops responding”
3. Trigger an event that removes the item from your inventory
4. Now, you should have 255 items with you. Go to the eastmost corner of Celadon City:

5. Toss 254 of your X Specials. Then swap the ‘X Special x1’ with ‘Nugget x1’ (35th item)
6. Try walking to the right – the map should now loop back to the left side of Celadon City. The amount of steps you take to the right determines the item you will get, so position yourself properly to obtain 8F. Swap it with the first item, then fly back to Celadon.
7. Store one of your newly acquired glitch items into the PC. Then buy any 3 items to bring your inventory back to normal.

Obtaining 8F Using Invalid Encounter Flags (Obsolete):


– A Ditto with a Cooltrainer move, nicknamed “R:u”
– At least 1 Escape Rope
– Good Rod on your 4th item slot
– Exactly 10 Pokemon in your current box (this tremendously increases the chances of Cooltrainer move working properly)
– Preferably a Bicycle, to make things a little bit faster.


1. Heal your Pokemon in Fuchsia City’s Pokemon Center.
2. Do the Safari Zone walk through walls glitch, with only Ditto in your party.
3. After you appear back at the Fuchsia City’s Center with noclip activated, walk exactly:
a) 19 steps west
b) 28 steps north
c) 1 step west
d) 29 steps north
e) 11 steps east
4. Open your Pokemon menu and close it (important). You may want to use bicycle now to travel faster – you won’t be able to do this later.
5. Go 11 steps west and keep walking south until you find yourself back on Route 18. Do not open your Start menu from now on.
6. Walk/bike to Seafoam Islands and enter the cave.
7. Encounter a wild Pokemon, and continuously try to use the Cooltrainer move. If it does not work after about 15 tries, quit the battle and start a new one. Do not open your Pokemon menu, Item menu or Start menu at all!
8. Eventually, the music will fade out, the move typing will become blank, and name of the opponent will get changed. Catch the resulting Pokemon – the game will state you caught a “98”, and your Good Rod will turn into an 8F.
9. Use an Escape Rope, as there’s a slight chance the game will crash after exiting the cave normally.

Obtaining 8F with a Corrupted Item Pack (Obsolete):

This method is not recommended – it has a lot of side effects and is terribly complicated. Use it only when any other method does not seem to work for you.


– A Pokemon on the first slot meeting very specific requirements:
> It needs to have a Super Glitch as a 4th move
> Its three moves besides the Super Glitch have to contain 25 characters in total
> One of its three moves needs to be 4 characters long
> This Pokemon needs to be able to learn Mega Kick through TM05
An example: ?L ||?M 4 (hex C6) with moves Body Slam, TM50, Quick Attack, [Super Glitch]
– Any Pokemon on the second slot you don’t care about, nicknamed “cccccccc”. It will be gone in the process, so don’t use your L100 Charizard.
– A Pokemon on the third slot knowing Fly.
– Exactly 3 useless items in your Bag. They will get destroyed again, so don’t pick anything important.
– TM05 (Mega Kick), deposited in the PC
– At least one free space in the PC to store your obtained 8F
– An empty Pokemon box currently selected, most likely box 12


Sadly, those side effects are actually quite annoying. But also, happily enough, one can fix them with 8F’s arbitrary code execution.

1. Your player name will become blank (the game will save just fine though). However, with 8F’s arbitrary code execution capabilities, one can change his name back to something nice.
2. Lower 5 Pokedex bytes will become corrupted, displaying some yet unseen species as caught. There’s no easy way to fix this, but it’s not a big deal unless you care about your Pokedex progression.
3. Your Pokemon box may get to a state where trying to release the glitch Pokemon inside will crash the game. This side effect does not happen every time, but if it does, again, this can be fixed with 8F’s arbitrary code execution.