Uploaded May 2020 | Updated September 2026, 2 weeks ago
In part two, we investigate why encountering the glitch Pokémon MissingNo multiplies the sixth item. Using SameBoy, GhidraBoy, memory searches, watchpoints, and Game Boy assembly, we find an out-of-bounds write from the Pokédex seen array into the item array.
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Watch this video and more on Hextree: app.hextree.io/courses/yt-gameboy-pokemon/pokemon-glitches
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Part 1: youtube.com/watch?v=p8OBktd42GI
Want to understand how to catch Mew? youtube.com/watch?v=U8fWTDUdWGA&list=PLniOzp3l9V82onKsktyyKlIenAAUj45Mk&index=6&t=0s
Checkout the whole GameBoy hacking playlist with stacksmashing: youtube.com/playlist?list=PLniOzp3l9V82onKsktyyKlIenAAUj45Mk
PwnAdventure Game Hacking Series: youtube.com/playlist?list=PLhixgUqwRTjzzBeFSHXrw9DnQtssdAwgG
GhidraBoy: github.com/Gekkio/GhidraBoy
SameBoy: github.com/LIJI32/SameBoy
CHAPTERS
00:00 - Recapping the MissingNo encounter bug
01:42 - Building a Cheat Engine-style memory search
02:51 - Narrowing down the sixth item amount
03:54 - Locating and editing the item array
05:18 - Tracing from the encounter to the item write
06:31 - From a huge trace to a write watchpoint
08:20 - Reading unfamiliar Game Boy assembly
09:06 - Loading banked ROM code with GhidraBoy
10:04 - Recovering the function around the write
11:05 - Following the HL address through the assembly
12:34 - Tracing the call across ROM banks
14:26 - Stepping through the bit-setting function
17:05 - Verifying the function with Tentacool
18:40 - The Pokédex seen bit array
19:14 - Writing out of bounds into the item array
20:30 - The complete MissingNo item-duplication chain
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#Pokemon #MissingNo #GameBoy #LiveOverflow
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In part two, we investigate why encountering the glitch Pokémon MissingNo multiplies the sixth item. Using SameBoy, GhidraBoy, memory searches, watchpoints, and Game Boy assembly, we find an out-of-bounds write from the Pokédex seen array into the item array.
LEARN ON HEXTREE (ad)
Learn hacking on Hextree: hextree.io
Watch this video and more on Hextree: app.hextree.io/courses/yt-gameboy-pokemon/pokemon-glitches
Join the Hextree Discord: discord.gg/xgQpCQCpvy
Part 1: youtube.com/watch?v=p8OBktd42GI
Want to understand how to catch Mew? youtube.com/watch?v=U8fWTDUdWGA&list=PLniOzp3l9V82onKsktyyKlIenAAUj45Mk&index=6&t=0s
Checkout the whole GameBoy hacking playlist with stacksmashing: youtube.com/playlist?list=PLniOzp3l9V82onKsktyyKlIenAAUj45Mk
PwnAdventure Game Hacking Series: youtube.com/playlist?list=PLhixgUqwRTjzzBeFSHXrw9DnQtssdAwgG
GhidraBoy: github.com/Gekkio/GhidraBoy
SameBoy: github.com/LIJI32/SameBoy
CHAPTERS
00:00 - Recapping the MissingNo encounter bug
01:42 - Building a Cheat Engine-style memory search
02:51 - Narrowing down the sixth item amount
03:54 - Locating and editing the item array
05:18 - Tracing from the encounter to the item write
06:31 - From a huge trace to a write watchpoint
08:20 - Reading unfamiliar Game Boy assembly
09:06 - Loading banked ROM code with GhidraBoy
10:04 - Recovering the function around the write
11:05 - Following the HL address through the assembly
12:34 - Tracing the call across ROM banks
14:26 - Stepping through the bit-setting function
17:05 - Verifying the function with Tentacool
18:40 - The Pokédex seen bit array
19:14 - Writing out of bounds into the item array
20:30 - The complete MissingNo item-duplication chain
SUPPORT
Per video: patreon.com/join/liveoverflow
Per month: youtube.com/channel/UClcE-kVhqyiHCcjYwcpfj9w/join
Buy my handwriting font (ad): shop.liveoverflow.com
WATCH, FOLLOW & READ
Second channel: youtube.com/LiveUnderflow
Twitch: twitch.tv/LiveOverflow
Twitter: twitter.com/LiveOverflow
Instagram: instagram.com/LiveOverflow
TikTok: tiktok.com/@liveoverflow_
LiveOverflow blog: liveoverflow.com
Hextree blog (ad): hextree.io/blog
#Pokemon #MissingNo #GameBoy #LiveOverflow
(ad) LiveOverflow YouTube channel is supported by advertisement and product placement.
