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Generation I Glitch Discussion

Can Yellow Missingno. duplicate 128 of an item? - Page 1

Can Yellow Missingno. duplicate 128 of an item?

Posted by: Zowayix001
Date: 2010-02-21 11:57:24
I know that Yellow Missingno. often freezes the game, but in the instance that it does not, can it still duplicate items? I've heard contradicting answers from various sources.

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: Torchickens
Date: 2010-02-21 12:24:04

I know that Yellow Missingno. often freezes the game, but in the instance that it does not, can it still duplicate items? I've heard contradicting answers from various sources.


Strictly speaking, the player can never encounter the Pokémon Yellow versions of Missingno through a normal wild Pokémon battle without the game crashing.

However technically it can duplicate items. If the player does manage to capture the 1F variant of the Yellow Missingno (e.g. by turning on the encounter code as soon as a Pokémon is about to be caught) then it will duplicate the sixth item as normal.

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: Wild MissingNo. appeared
Date: 2010-02-21 12:41:01
Yellow MissingNo. can be seen in the wild, as it's a 50% chance he'll crash the game, or 50% chance you can capture him, where sometimes you may get side-effects like MissingNo. Learned! over and over, or an evolution (this has never happened to me yet). The Yellow MissingNo. does duplicate items in the sixth slot, before my Yellow data died (after three years of surviving), I had my HM05 in the 6th slot and after I'd captured the Yellow MissingNo. it became dulplicated and I was stuck with the item, it would never disppear form my Items when I placed it in the box. Yellow MissingNo. can been seen by normal game cartridge, GS/GG/AR, but in a ROM version you have to turn the encounter off, other wise the game will crash/emulator error.

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: Stackout
Date: 2010-02-22 10:34:02
I assume that MissingNo. Ghost/Skel in Yellow still changes 6th item quantity to 127, and 255 if caught.

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: OwnageMuch
Date: 2010-02-23 00:05:26
Missingno never changed it to an amount it increases it by 128/255

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: Stackout
Date: 2010-02-23 11:20:57

Missingno never changed it to an amount it increases it by 128/255


..but the byte would be set to DEC 128 (i suppose my last post was a typo)/255, because, say that  MissingNo gets seen. The game finds the pokedex byte for MissingNo, and sets it to DEC 128 (because in the pokedex area in RAM, not seen is DEC 0, seen is DEC 128, and caught is DEC 255) – and the pokedex byte is the 6th item quantity (because the items area in RAM is directly after the pokedex area).

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: Ketsuban
Date: 2010-02-23 14:24:32
Actually, Wack0, think of it this way.

If your sixth item is (say) Rare Candies,and you have four of them, the qty byte looks like:

…00000100…

If you encounter MissingNo., the second most significant bit is set, changing the byte to:

…10000100…

which would give you 128 more Rare Candies as 10000100 = 132.

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: GARYM9
Date: 2010-02-23 14:53:20
No, it treats the number of items to add to the sixth slot as a signed byte (with signed bytes, 127 is the highest and -128 is the lowest or vice versa depending on the system) then adds the max amount to the sixth slot (and since all items are unsigned bytes, the max is 255 and since there's no overflow checking flag, it can roll over to 0 and start again)

Re: Can Yellow Missingno. duplicate 128 of an item?

Posted by: echinodermata
Date: 2010-02-23 18:47:40
Ketsuban is correct.