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diff --git a/src/vay8910.h b/src/vay8910.h
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+++ b/src/vay8910.h
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+//
+// Virtual AY-3-8910 Emulator
+//
+// by James Hammons
+// (C) 2018 Underground Software
+//
+
+#ifndef VAY8910_H
+#define VAY8910_H
+
+#include <stdint.h>
+
+struct VAY_3_8910
+{
+	// User visible registers
+	uint16_t period[3];		// Channel A-C period
+	int16_t volume[3];		// Channel A-C volume (non-envelope mode)
+	bool envEnable[3];		// Channel A-C envelope enable
+	bool toneEnable[3];		// Channel A-C tone enable
+	bool noiseEnable[3];	// Channel A-C noise enable
+	uint16_t noisePeriod;	// Noise period (5 bits * 16)
+	uint32_t envPeriod;		// Envelope period (16 bits * 256)
+	bool envAttack;			// Envelope Attack bit
+	bool envAlternate;		// Envelope Alternate bit
+	bool envHold;			// Envelope Hold bit
+	// Internal registers
+	uint16_t count[3];		// Channel A-C current count
+	bool state[3];			// Channel A-C current state
+	uint16_t noiseCount;	// Noise current count
+	bool noiseState;		// Noise state
+	uint32_t envCount[3];	// Envelope current count
+	int16_t envDirection[3];// Envelope direction (rising, 0, or falling)
+	uint32_t prng;			// Psuedo RNG (17 bits)
+	uint8_t regLatch;		// Register latch (written by 6522VIA)
+	uint8_t data;			// Data lines (written by 6522VIA)
+	uint8_t id;				// Chip ID (optional)
+
+	VAY_3_8910();
+	void Reset(void);
+	void WriteControl(uint8_t);
+	void WriteData(uint8_t);
+	void SetRegister(void);
+	uint16_t GetSample(void);
+
+	// Class variables
+
+	// Maximum volume that can be generated by one voice
+	static float maxVolume;
+	// Normalized volumes (zero to one) for AY-3-8910 output, in 16 steps
+	static float normalizedVolume[16];
+};
+
+// Exported variables
+extern bool logAYInternal;
+
+#endif	// VAY8910_H
+