Initial code upload

Add source code files exactly as provided by
[RHDN](https://www.romhacking.net/utilities/178/)

src/M6502.H

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+/* Multi-6502 32 Bit emulator */
+
+/* Copyright 1996, 1997, 1998, Neil Bradley, All rights reserved
+ *
+ * License agreement:
+ *
+ * (M6502 Refers to both the assembly code emitted by make6502.c and make6502.c
+ * itself)
+ *
+ * M6502 May be distributed in unmodified form to any medium.
+ *
+ * M6502 May not be sold, or sold as a part of a commercial package without
+ * the express written permission of Neil Bradley (neil@synthcom.com). This
+ * includes shareware.
+ *
+ * Modified versions of M6502 may not be publicly redistributed without author
+ * approval (neil@synthcom.com). This includes distributing via a publicly
+ * accessible LAN. You may make your own source modifications and distribute
+ * M6502 in source or object form, but if you make modifications to M6502
+ * then it should be noted in the top as a comment in make6502.c.
+ *
+ * M6502 Licensing for commercial applications is available. Please email
+ * neil@synthcom.com for details.
+ *
+ * Synthcom Systems, Inc, and Neil Bradley will not be held responsible for
+ * any damage done by the use of M6502. It is purely "as-is".
+ *
+ * If you use M6502 in a freeware application, credit in the following text:
+ *
+ * "Multi-6502 CPU emulator by Neil Bradley (neil@synthcom.com)"
+ *
+ * must accompany the freeware application within the application itself or
+ * in the documentation.
+ *
+ * Legal stuff aside:
+ *
+ * If you find problems with M6502, please email the author so they can get
+ * resolved. If you find a bug and fix it, please also email the author so
+ * that those bug fixes can be propogated to the installed base of M6502
+ * users. If you find performance improvements or problems with M6502, please
+ * email the author with your changes/suggestions and they will be rolled in
+ * with subsequent releases of M6502.
+ *
+ * The whole idea of this emulator is to have the fastest available 32 bit
+ * Multi-6502 emulator for the PC, giving maximum performance. 
+ */ 
+
+/* General 6502 related goodies */
+
+#ifndef _M6502_H_
+#define _M6502_H_
+
+#ifndef UINT32
+#define UINT32  unsigned long int
+#endif
+
+#ifndef UINT16
+#define UINT16  unsigned short int
+#endif
+
+#ifndef UINT8
+#define UINT8   unsigned char
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern UINT32 m6502nmi(void);
+extern UINT32 m6502int(UINT32);
+extern UINT32 m6502exec(UINT32);
+extern void m6502reset(void);
+extern UINT32 m6502GetElapsedTicks(UINT32);
+extern void m6502ReleaseTimeslice();
+
+extern UINT32 m6502zpnmi(void);
+extern UINT32 m6502zpint(UINT32);
+extern UINT32 m6502zpexec(UINT32);
+extern void m6502zpreset(void);
+extern UINT32 m6502zpGetElapsedTicks(UINT32);
+extern void m6502zpReleaseTimeslice();
+
+extern UINT32 m6502bsnmi(void);
+extern UINT32 m6502bsint(UINT32);
+extern UINT32 m6502bsexec(UINT32);
+extern void m6502bsreset(void);
+extern UINT32 m6502bsGetElapsedTicks(UINT32);
+extern void m6502bsReleaseTimeslice();
+
+extern UINT16 m6502bspc;
+extern UINT16 m6502zppc;
+extern UINT16 m6502pc;
+
+#ifndef _MEMORYREADWRITEBYTE_
+#define _MEMORYREADWRITEBYTE_
+
+struct MemoryWriteByte
+{
+	UINT32 lowAddr;
+	UINT32 highAddr;
+	void (*memoryCall)(UINT32, UINT8, struct MemoryWriteByte *);
+	void *pUserArea;
+};      
+
+struct MemoryReadByte
+{
+	UINT32 lowAddr;
+	UINT32 highAddr;
+	UINT8 (*memoryCall)(UINT32, struct MemoryReadByte *);
+	void *pUserArea;
+};      
+
+#endif // _MEMORYREADWRITEBYTE_
+
+/* WARNING: Do not use a sizeof() operator on this structure. The assembly
+ * code will pack other context relevant data after this space. Use the
+ * GetContextSize() call to obtain the specifics of the context.
+ */
+
+struct m6502context
+{
+	UINT8 *m6502Base;                               /* 32 Bit pointer to base memory address */
+
+	/* 32 Bit pointers to user trap address structure array */
+
+	struct MemoryReadByte *m6502MemoryRead;
+	struct MemoryWriteByte *m6502MemoryWrite;
+
+	/* This context's register dump */
+
+	UINT16 m6502af;                 /* A & Flags */
+	UINT16 m6502pc;                 /* Program counter */
+	UINT8 m6502x;                   /* X register */
+	UINT8 m6502y;                   /* Y register */
+	UINT8 m6502s;                   /* S register */
+	UINT8 irqPending;
+};
+
+struct m6502bscontext
+{
+	UINT8 *m6502Base;                               /* 32 Bit pointer to base memory address */
+
+	/* 32 Bit pointers to user trap address structure array */
+
+	struct MemoryReadByte *m6502MemoryRead;
+	struct MemoryWriteByte *m6502MemoryWrite;
+
+	UINT8 *pbBankSwitch[32];		/* 32 2K addresses */
+
+	/* This context's register dump */
+
+	UINT16 m6502af;                 /* A & Flags */
+	UINT16 m6502pc;                 /* Program counter */
+	UINT8 m6502x;                   /* X register */
+	UINT8 m6502y;                   /* Y register */
+	UINT8 m6502s;                   /* S register */
+	UINT8 irqPending;
+};
+
+typedef struct m6502context CONTEXTM6502;
+typedef struct m6502bscontext CONTEXTM6502BS;
+
+extern void m6502SetContext(struct m6502context *);
+extern void m6502GetContext(struct m6502context *);
+extern UINT32 m6502GetContextSize(void);
+
+extern void m6502zpSetContext(struct m6502context *);
+extern void m6502zpGetContext(struct m6502context *);
+extern UINT32 m6502zpGetContextSize(void);
+
+extern void m6502bsSetContext(struct m6502context *);
+extern void m6502bsGetContext(struct m6502context *);
+extern UINT32 m6502bsGetContextSize(void);
+
+extern void m6502init(void);
+extern void m6502zpinit(void);
+extern void m6502bsinit(void);
+
+extern UINT8 *m6502bspbBankSwitch[32];	// Bank switching registers
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif // _M6502_H_