implemented draw function in interpreter

Interpreter.hpp

@@ -14,6 +14,7 @@ private:
   using sreg_t = unsigned;
 
 public:
+  constexpr static sreg_t scLowRestFontAddr = 0x0000;
   constexpr static sreg_t scResetVector = 0x0200;
   constexpr static size_t scMemorySize = 4096;
 
@@ -35,10 +36,11 @@ public:
 public:
   Interpreter(unsigned ticksPerSecond, Display &display, Buzzer &buzzer, Keypad &keypad);
   void tick();
-  void loadProgram(size_t where, char const* data, size_t count);
+  void loadProgram(char const* data, size_t count, size_t where = scResetVector);
 
 private:
   void executeArithmetic(Opcode opcode, int iReg, reg_t operand);
+  void executeDraw(uint8_t x, uint8_t y, uint8_t n);
 
 private:
   std::vector<uint8_t> mvMemory;
@@ -49,6 +51,7 @@ private:
   const unsigned mcTicksPerSecond;
   sreg_t mvSpecialReg[SR_COUNT];
   reg_t mvReg[R_COUNT];
+  bool mIsHighResMode;
 }; // class Interpreter
 
 }; // namespace chocohip8