Self-hosted EmulatorJS 4.2.3 frontend retained byte-for-byte from COSOM Madden player. Original: https://github.com/EmulatorJS/EmulatorJS/tree/v4.2.3 Package: https://registry.npmjs.org/@emulatorjs/emulatorjs/-/emulatorjs-4.2.3.tgz Retained modifications: automatic CDN version check disabled; remote core fallback removed; original sources concatenated into emulator.min.js; original CSS copied into emulator.min.css. Genesis Plus GX core archive unchanged from COSOM Sol-Feace, build 2025-06-14. Core source: https://github.com/EmulatorJS/Genesis-Plus-GX Upstream: https://github.com/ekeeke/Genesis-Plus-GX Single-thread legacy/WebGL1 core. Genesis A/B/C controls reuse segaCD frontend layout. The cartridge program bytes are unchanged; optional browser cheats use the core's reversible in-memory instruction patch interface. These are optional enhancements. No patched cartridge download is generated. SMD input transform is documented in intake.json.