Words used on this site
The hard words on this site, in plain words. Each one means what the guides mean by it.
How to use this page
The words are in A to Z order. Each card gives the meaning this site uses, in one or two short sentences.
Each word is also explained on the page that uses it. To see the words at work, read the Overview or the Deep Dive.
The words
64-bit
A modern PC stores an address in 8 bytes. The N64 used 4. A port must fix code that counts on the old sizes.
6502
The chip family in the NES and Super Nintendo.
68000
The chip family in the Genesis, Amiga and CD-i.
Address
A number that says where something sits in memory or in a file. Task cards name addresses so Claude knows where to look.
ARM
The chip family in the Game Boy Advance, DS, 3DS, Switch and Switch 2.
Assembly
Machine code printed as text, one short line for each instruction. A disassembler makes it.
Assets
A game's art, sound and level data. A public port cannot ship them. It pulls them from your own copy of the game.
Big-endian
A big number is stored with its big end first. N64 game files are big-endian.
Binary
A file of machine code, such as a game file. To map the binary means to list what is inside it.
Budget
The task card line that says when to stop. It is a number of failed tries, or minutes with no progress.
Build
To turn source code into the finished program with a compiler and a linker. A build script does it with one command.
Build check
The code compiles with no errors and no new warnings. It is the weakest check, so never accept it alone.
Byte
One small number in a file, from 0 to 255. A game file is one long row of bytes.
Byte match
The rebuilt file has the same hash as the original. It is the strongest check.
Byte order
The order in which the bytes of a big number are stored. A missed swap can turn 1 into 16,777,216.
C
A programming language. Most decomps and recomps are written in C. C++ is a bigger language built on it.
Checksum
A number worked out from a file's bytes to check it. On this site it means the same as a hash.
Chip family
A group of chips that run the same kind of instructions. Tools are built for a family, not for one console.
Claude Code
An AI tool from Anthropic that works in your project folder. It reads files, writes code and runs tools.
CLAUDE.md
A short rule file that Claude Code loads at the start of each session. It is advice, not a lock.
Commit
One saved step in git, the tool that tracks your repo. Real projects commit after every proven unit.
Compaction
When a chat gets long, Claude Code swaps the old part for a short summary. A rule you only typed in chat can get lost.
Compatibility-layer port
The old machine code runs on a PC through a thin layer that fakes the console. It only works when the console has a PC-type chip.
Compiler
A tool that turns source code into machine code. Each version makes its own choices, so a match needs the exact original version.
Compiler flags
The settings you give a compiler. A match needs the same compiler, the same version and the same flags as the original.
Context
All the text Claude holds in a session. Every request sends all of it again, so keep it small.
Dead end
Something you tried that did not work. Write it in the findings file so no later session tries it again.
Debug build
A version of a game made for testing in the studio. It sometimes still holds the names the shipped game lost.
Decomp
Short for decompilation. It is source code rebuilt from a game's machine code, so people can read it and build the game from it.
Decompile
To work backward from a game's machine code to source code a person can read. The result is called a decomp.
Deny rule
A settings line that names an action Claude Code always refuses, such as an edit to the check script.
Diff
A list of what changed between two files or two builds. A fresh reviewer reads the diff to look for cheating.
Differential test
Run the same input through the original code in an emulator and through your new code. Then compare memory, registers or frame pictures.
Disassembler
A tool that turns a game's bytes into assembly. It needs a map of which bytes are code and which are data.
DONE, PARTIAL, BLOCKED
The only three words a report may start with. DONE needs pasted proof. PARTIAL says what works. BLOCKED says why Claude stopped.
Drift
When Claude leaves the job you gave it. A task card, a fence and a check keep it on track.
Dump
To copy a game off its disc or cartridge yourself. Use only a dump of a game you own.
Effort
How much work a model puts into each turn: low, medium, high, xhigh or max. In Claude Code, every model starts at medium.
Emulator
A program that acts like a console on your PC. It runs the original game, so you can compare it with your new code.
Endianness
Another word for byte order. It says which end of a number is stored first.
Fence
The list of paths Claude may edit in one task. Everything else is read-only.
First light
The smallest proof that it all works. Goal A: a window shows the first frame. Goal B: one small file matches.
Fresh reviewer
A new session with no memory of the work. It runs the check again and reads the diff to look for cheating.
Function
One small job in the code, with a start and an end. In Goal B, one function is the usual unit of work.
Function edges
Where a function starts and ends. Nothing in the file marks them, so tools guess. A wrong edge makes an honest match impossible.
Generated code
Code written by a tool, such as the C from a recompiler. Never edit it by hand. Fix the tool or its config instead.
Ghidra
A tool for studying game files. It lists the functions in a file and decompiles them.
Goal A
Get the game running on a PC. Every guide starts here. The guides call it Path A.
Goal B
Turn the whole game into source code a person can read, so it can be ported. The guides call it Path B.
Golden run
The game starts with no person and reaches a known point in a set time without a crash. A screenshot or log line proves it.
Hash
A short fingerprint of a file. Two files with the same hash have the same bytes.
Hook
A command Claude Code runs by itself at set moments. A PreToolUse hook can block a tool call, such as an edit to a guarded file.
Inline assembly
Raw assembly written inside C. Strict matching projects ban it, since it forces a match with no real C behind it.
Job type
A name for one kind of work, such as bulk or hard. A table on Claude Setup gives each one a model and an effort.
Jump table
A list of addresses stored as data. The code picks one and jumps to it. Tools that only read the file can lose track.
Ledger
A file that keeps the state of the project. The function ledger has one row for each function, with its address, size and status.
Library code
Code that came with the console's kit, not written for the game. Mark it in the ledger so nobody decompiles it by hand.
Linker
A tool that joins object files into the final program. It fills in each call's address at link time.
Little-endian
A big number is stored with its small end first. A PC is little-endian, so a port from a big-endian console must swap bytes.
Machine code
The numbers a game system's chip runs. A compiler makes them from source code. People can hardly read them.
Match
Your C builds to the exact bytes of the original. A diff tool at 100% is a hint. The full build check decides.
Matching decompilation
You write C that the game's original compiler turns into the exact same bytes. A tool compares the bytes to prove it.
Max 20x
The bigger Claude plan, now called Ultra. It costs $200 a month. Verified accounts have no five-hour limit.
Max 5x
The smaller Max plan, now called Max. It costs $100 a month and has a five-hour limit.
MCP server
An add-on program that plugs an outside tool, such as Ghidra, into Claude. A plain command-line tool uses less context.
Middleware
Code a studio bought in from another company. Mark it in the ledger so nobody decompiles it by hand.
Milestone
A step along the way, written in SCOPE.md with its own check. The ledger shows when it is met.
MIPS
The chip family in the N64, PlayStation, PS2 and PSP. splat works on all four.
Model
The AI that does the work. Claude Code can run four: Fable 5.2, Opus 5.5, Sonnet 5.5 and Haiku 5.5. A table pairs each job with one.
Model switch
Safety checks can move a session from Fable 5.2 or Opus 5.5 to an older model. Run /model to switch back.
Non-matching decompilation
Readable C that acts like the original but does not build to the same bytes. Tests check it instead, so small bugs can hide.
objdiff
A tool that compares your built code with the original, one function at a time. It shows a match score.
Object file
The compiled form of one source file. The linker joins object files into the final game.
Parking lot
The file notes/parking-lot.md. Claude writes side ideas and other bugs there and never acts on them. You decide.
Permission mode
A setting for what Claude may do without asking you. Press Shift+Tab to change it.
Permuter
decomp-permuter makes small random changes to your C and keeps the ones that score closer. Its output is odd code, so use it late.
Phase
One of seven stages, numbered 0 to 6. They are Scope, Setup, Map, First light, Grind, Harden and Port.
Plan mode
A mode where Claude reads and proposes a plan. It makes no source edits until you approve the plan.
Port
To move a game to a new system, such as a PC. A port of a decomp swaps the console parts for PC parts.
PowerPC
The chip family in the GameCube, Wii, Wii U, Xbox 360 and PS3.
Prior work
Anything that already exists for your game. That means decomps, recomps, ports, symbol files, debug builds and sister games.
Pull request
A request to add your changes to someone else's project. Read its rules first. Some projects ban AI-written code.
Recomp
Short for static recompilation, or the game it makes. A recomp runs on a PC, but its C is hard to read. It is not a decomp.
Recompile
To turn code into machine code again, often for a new system. On this site it mostly means static recompilation.
Recompiler
The tool that does static recompilation. It reads a game's machine code and writes C that does the same steps.
Register
A slot in the chip that holds one number. In a recomp, the registers become fields in C code.
Reimplementation
Writing a new engine from scratch that loads the old game's data files. It is a different job from decompiling.
Repo
Short for repository. It is your project folder, with each step saved in git. Keep game files outside it.
ROM
The data of a cartridge game, saved as one file. An N64 ROM file can end in .z64.
Runtime
Code that stands in for the console: graphics, sound, input, files and system services. You and Claude write it for a recomp.
Scope Contract
One page saved as SCOPE.md. It holds the goal, game version and hash, technique, milestone and what is out of scope. Only you change it.
SDK
Short for software development kit. It is the kit of tools and library code a console maker gives to game studios.
Session
One chat with Claude Code, from start to end. Give each session one unit of work.
Skill
A folder with a SKILL.md file of steps. Claude loads the full steps only when the job fits or you call it.
Source code
The words people write to make a program. A compiler turns them into machine code.
Splitter
A tool that cuts a game file into the pieces listed in a config file. splat and decomp-toolkit are splitters.
Static recompilation
A tool reads the game's machine code once, before the game runs. It writes C that does the same steps. It is the fastest way to a running game.
Stub
A stand-in that does nothing yet. Stubs are a debt. List each one, and never count a stubbed call as done.
Subagent
A helper Claude with its own context. It does a side task and sends back a short summary. It does not see your chat.
SuperH
The chip family in the Saturn, 32X and Dreamcast.
Symbol
The name of a function or a piece of data. Studios strip symbols out before a game ships.
System call
A request the game makes to the console's own software, such as open a file or read the pad. The runtime answers it.
Task card
A prompt with the same named parts every time. They are goal, read first, fence, check, budget, if blocked, other problems and report.
Token
A small piece of text that a model reads or writes. A million tokens is roughly 555,000 words.
Unit
The smallest piece of work with its own pass or fail check. That is one function, one crash or one missing call.
Worktree
A second copy of your repo on its own branch. Each parallel session gets one, so no two write over each other.
WSL
Short for Windows Subsystem for Linux. It is Linux inside Windows. Many N64 projects are built for Linux first.
x86
The chip family in PCs, the first Xbox, PS4 and PS5. A PC is x86 too, so old code can run behind a thin layer.
Z80
The chip family in the Game Boy, Game Boy Color and Game Gear.
Sources
These meanings come from the pages on this site and the sources they list. The main ones are below.