How to make unstable Yellow MissingNo. not freeze every time with arbitrary code execution ^-^
52Notes:
A preliminary to something mjdxp suggested. ^-^ https://www.youtube.com/channel/UCVYDU8oQJFiHYLco5qVtayw This will let you catch Yellow MissingNo. and enable the walking characters effects/related corruptions every time.
It probably won't work on VisualBoyAdvance, so use a late revision of BGB, or actual console (3DS VC may work too, even though it has inaccuracies).
As we destroy the save with 4F (without resetting the game so you don't lose it), you'll have to save the game each time after encountering the Yellow MissingNo, then use 4F again, save the game again and repeat. This takes the stable unstable Yellow MissingNo. concept used in speedruns; in which clearing your save file, not saving, and encountering Yellow MissingNo. as the first glitch Pokémon will secure that it won't freeze the game. ^^
For some reason, it freezes with this method after sending out the first Pokémon; so we can just override the battle type to FF so you don't send out a Pokémon, then use the Master Ball.
At DA64:
06 1C 21 80 7E CD 84 3E 3E 1F EA 58 D0 3E FF EA 59 D0 AF EA A9 D0 C9
You can write these bytes one at at time with https://glitchcity.wiki/Reusable_RAM_writer , converting each one from hexadecimal to decimal for the quantities. (e.g. DA64 write 06 (6 in decimal), DA65 write 1C (28 in decimal) and so on until the C9 at DA7A)
- For 4F. Calls the routine to clear the game's save data, without actually resetting the game and reloading the save; so progress from the previous save just remains in RAM. Sets battle type to FF (enables automatic selection, so you'll have to arrange Poké Flute at the top of the items menu page (using it will close the menu and load the Yellow MissingNo. battle), and have Master Ball at the absolute top of the inventory to catch the MissingNo. Replace the 3E 1F with another MissingNo. index number if desired;
Hex Dec
1F 31
20 32
32 50
34 52
38 56
3D 61
3E 62
3F 63
43 67
44 68
45 69
4F 79
50 80
51 81
56 86
57 87
5E 94
5F 95
73 115
79 121
7A 122
7F 127
86 134
87 135
89 137
8C 140
92 146
9C 156
9F 159
A0 160
A1 161
A2 162
AC 172
AE 174
AF 175
B5 181
(Not unstable MissingNo.s):
B6 182
B7 183
B8 184
Note I haven't tested this everywhere and with every index number of MissingNo. yet.
Enjoy~ :]