MAME file terminology / 2026-08-01

MAME ROM, CHD, and sample files explained

Identify what each MAME asset class represents and diagnose the missing layer without treating every file as a ROM.

8 minute terminology guideOfficial MAME 0.289; names and requirements remain machine- and release-specific

MAME ROM, CHD, and sample files explained

ROM files hold fixed device data, CHDs represent disk or other mass-storage media, and samples are optional recorded sounds used by certain emulated systems. They have different paths, validation methods, and dependencies; read the exact audit or runtime message before replacing anything.

Do this in order

  1. 01

    Record the exact MAME revision and machine short name.

  2. 02

    Run the machine's ROM audit and copy every named missing or incorrect item.

  3. 03

    Classify each item as ROM/device data, disk media, or a runtime sample requirement.

  4. 04

    For CHDs, inspect the expected machine folder and parent relationship; do not ZIP the CHD.

  5. 05

    For samples, confirm the machine actually uses them and inspect the configured sample path.

  6. 06

    Return only to your authorized source or own dump, then rerun the same audit and launch test.

Decision and diagnostic table

AssetRolePrimary evidence
ROMFixed program, graphics, firmware, or device dataMAME ROM audit and expected hash
CHDCompressed disk or other mass-storage imageCHD header plus MAME dependency
SampleRecorded sound used by specific driversRuntime message and sample path
ArtworkOptional presentation layoutLayout/artwork path, not ROM audit

Missing does not name a legal source

An audit identifies a technical dependency, not permission to fetch it. Keep provenance separate from compatibility.

Each class has a different repair

A CHD folder change cannot repair a bad ROM hash, and a sample archive cannot replace unemulated sound hardware. Act on the exact class named by the target build.

First-party sources

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