Add a fake6502.h header extracting the interface from fake6502

src/fake6502.c

@@ -105,6 +105,8 @@
 #include <stdio.h>
 #include <stdint.h>
 
+#include "fake6502.h"
+
 //6502 defines
 #define UNDOCUMENTED //when this is defined, undocumented opcodes are handled.
                      //otherwise, they're simply treated as NOPs.

src/fake6502.h

@@ -0,0 +1,57 @@
+// Header for declaring external interface to fake6502.c
+
+
+/* Fake6502 requires you to provide two external     *
+ * functions:                                        *
+ *                                                   */
+uint8_t read6502(uint16_t address);
+void write6502(uint16_t address, uint8_t value);
+/*                                                   *
+ * You may optionally pass Fake6502 the pointer to a *
+ * function which you want to be called after every  *
+ * emulated instruction. This function should be a   *
+ * void with no parameters expected to be passed to  *
+ * it.                                               *
+ *                                                   *
+ * This can be very useful. For example, in a NES    *
+ * emulator, you check the number of clock ticks     *
+ * that have passed so you can know when to handle   *
+ * APU events.                                       *
+ *                                                   *
+ * To pass Fake6502 this pointer, use the            *
+ * hookexternal(void *funcptr) function provided.    *
+ *                                                   *
+ * To disable the hook later, pass NULL to it.       */
+
+
+void reset6502();
+/*   - Call this once before you begin execution.    */
+
+void exec6502(uint32_t tickcount);
+/*   - Execute 6502 code up to the next specified    *
+ *     count of clock ticks.                         */
+
+void step6502();
+/*   - Execute a single instrution.                  *
+ *                                                   */
+
+void irq6502();
+/*   - Trigger a hardware IRQ in the 6502 core.      */
+ 
+void nmi6502();
+/*   - Trigger an NMI in the 6502 core.              */
+
+void hookexternal(void *funcptr);
+/*   - Pass a pointer to a void function taking no   *
+ *     parameters. This will cause Fake6502 to call  *
+ *     that function once after each emulated        *
+ *     instruction.                                  */
+
+extern uint32_t clockticks6502;
+/*   - A running total of the emulated cycle count.  */
+ 
+extern uint32_t instructions;
+/*   - A running total of the total emulated         *
+ *     instruction count. This is not related to     *
+ *     clock cycle timing.                           */
+