AccuracyCoin is a comprehensive NES ROM-based test suite designed to verify the accuracy of NES emulators and hardware implementations. Containing 141 individual tests covering CPU instructions, PPU rendering, APU sound, timing behaviors, and hardware quirks, it serves as a valuable tool for emulator developers seeking to ensure their implementations match the behavior of original NES hardware (specifically targeting RP2A03G CPU and RP2C02G PPU revisions). The application features a navigable test menu accessible via standard NES controller inputs, allowing users to select and run specific tests, skip problematic tests, and view detailed pass/fail results with error codes. A distinctive debug menu, activated by the Select button, provides real-time inspection of memory contents including CPU registers and specific RAM regions, facilitating troubleshooting without external debugging tools. Each test is meticulously crafted to isolate specific hardware behaviors, often employing cycle-accurate timing techniques to probe edge cases and timing-dependent phenomena. What sets AccuracyCoin apart is its sophisticated approach to handling hardware variations - many tests acknowledge multiple valid behaviors that different NES revisions or implementations might exhibit, assigning success codes rather than simple pass/fail outcomes. This nuanced verification approach, combined with the comprehensive coverage of NES subsystems and the thoughtful design of the test harness and debug utilities, makes it a standout resource in the NES homebrew and emulator development communities.