# Rom Bin Cue Chd Conversion

> Convert disc-based ROM images from BIN/CUE to CHD and back with chdman from MAME or rom-tools. Use when the user needs to shrink, organize, verify, or round-trip CD-based game images on macOS or Windows, especially for RetroArch, DuckStation, PS1/PSX, Sega CD, TurboGrafx-CD, Neo Geo CD, or when they mention BIN/CUE, cue sheets, CHD, chdman, or rom-tools.

- Skill: `ashref-dev/rom-bin-cue-chd-conversion` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ashref-dev/rom-bin-cue-chd-conversion`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ashref-dev/rom-bin-cue-chd-conversion/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: Ashref-dev (https://skillmd.com/u/ashref-dev)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/ashref-dev/rom-bin-cue-chd-conversion

---


# BIN/CUE to CHD Conversion

Use this skill when converting CD-based disc images between BIN/CUE and CHD format. Prefer CHD for storage and emulator workflows when the target emulator supports it, and preserve the original BIN/CUE set until the CHD has been validated.

## What this skill does

- Converts disc-based ROM sets from `.cue` + `.bin` to `.chd`
- Extracts CHD files back to `.cue` + `.bin`
- Verifies CHD integrity
- Handles multi-track CD images correctly when the `.cue` sheet is accurate
- Gives commands for macOS and Windows

## Use the right tool

- `chdman createcd` for BIN/CUE -> CHD
- `chdman extractcd` for CHD -> BIN/CUE
- `chdman info` for format and compression details
- `chdman verify` for CHD integrity checks

Do not use archive tools or ad-hoc compression to make CHD files. The CHD format needs `chdman` so the sector layout and metadata are preserved correctly.

## Before you convert

1. Find the `.cue` file for the game.
2. Confirm every referenced `.bin` file exists and the names match exactly.
3. Keep the source files untouched until the CHD has been verified.
4. Preserve the original basename unless the user asks for a different naming scheme.
5. For multi-disc games, convert each disc separately and keep the disc number in the filename.

If there is only a loose `.bin` file and no valid `.cue`, stop and ask for the cue sheet or a proper disc manifest. `createcd` is meant to read the cue sheet and the tracks it references.

## macOS workflow

### Install chdman

Prefer the system package that provides `chdman`:

- Homebrew: `brew install rom-tools`
- If the user already has MAME installed, use the `chdman` binary from that installation instead of reinstalling

Confirm availability:

- `which chdman`
- `chdman --version`

### Convert BIN/CUE to CHD

```bash
chdman createcd -i "Game Name.cue" -o "Game Name.chd"
```

Useful options:

- `-f` overwrite an existing output file
- `-v` print verbose progress
- `-np <count>` limit or increase worker threads
- `-c <compression list>` only when you have a reason to change the default compression

For most CD images, the default compression choices are fine. Change them only if the user specifically wants different tradeoffs.

### Verify the CHD

```bash
chdman info -i "Game Name.chd"
chdman verify -i "Game Name.chd"
```

`info` shows the compression, hunk size, size, and hashes. `verify` checks the file integrity.

### Extract CHD back to BIN/CUE

```bash
chdman extractcd -i "Game Name.chd" -o "Game Name.cue" -ob "Game Name.bin"
```

If the user wants one binary file per track instead of one combined BIN, add `-sb`:

```bash
chdman extractcd -i "Game Name.chd" -o "Game Name.cue" -sb
```

## Windows workflow

### Install chdman

Install MAME or a rom-tools package that includes `chdman.exe`, then make sure it is on `PATH`.

Verify it in PowerShell:

```powershell
Get-Command chdman.exe
chdman.exe --version
```

If `chdman.exe` is not on `PATH`, call it with a full path.

### Convert BIN/CUE to CHD

PowerShell:

```powershell
& "C:\MAME\chdman.exe" createcd -i "Game Name.cue" -o "Game Name.chd"
```

Command Prompt:

```cmd
chdman.exe createcd -i "Game Name.cue" -o "Game Name.chd"
```

### Verify the CHD

```powershell
& "C:\MAME\chdman.exe" info -i "Game Name.chd"
& "C:\MAME\chdman.exe" verify -i "Game Name.chd"
```

### Extract CHD back to BIN/CUE

```powershell
& "C:\MAME\chdman.exe" extractcd -i "Game Name.chd" -o "Game Name.cue" -ob "Game Name.bin"
```

Use `-sb` when the user wants one BIN per track:

```powershell
& "C:\MAME\chdman.exe" extractcd -i "Game Name.chd" -o "Game Name.cue" -sb
```

## Multi-disc and emulator notes

- Convert each disc separately.
- Keep disc numbers in the filenames, such as `Game Name (Disc 1).chd`.
- If the user wants convenient disc swapping, create an `.m3u` playlist that points at the per-disc CHD files.
- For RetroArch, DuckStation, and similar emulators, CHD is usually the cleaner long-term format for CD-based games.

## Troubleshooting

- If `chdman` cannot find tracks, the `.cue` file probably has a filename mismatch. Fix the cue or rename the referenced files so they match exactly.
- If the command fails because the output already exists, rerun with `-f` only when overwriting is intentional.
- If the user is on Windows and the command is not found, use the full path to `chdman.exe` or fix `PATH` before trying again.
- If the conversion succeeds but the emulator does not load the CHD, verify the CHD with `chdman info` and `chdman verify`, then keep the original BIN/CUE as a fallback.

## Good handoff behavior

- Explain the conversion result in plain language.
- Tell the user where the CHD file was written.
- Mention whether the source BIN/CUE was left untouched.
- If extraction was requested, tell the user whether the output is a single BIN or split BIN tracks.