Fixed the subtraction carryover bug!

Co-authored-by: sigonasr2 <sigonasr2@gmail.com>

main.cpp

@@ -9,7 +9,7 @@
 
 using namespace olc;
 
-bool USE_DEBUG_DISPLAY=false;
+bool USE_DEBUG_DISPLAY=true;
 int EMULATOR_SCREEN_WIDTH = 64;
 int EMULATOR_SCREEN_HEIGHT = 32;
 int EMULATOR_PIXEL_SIZE=5;
@@ -154,12 +154,23 @@ public:
 						advanceTimers(); //After 10 instructions, 1/60th of a second has passed.
 					}
 					DrawDisplay();
+				} else
+				if (GetKey(END).bHeld){
+					for (int i=0;i<10;i++){
+						RunInstruction();
+						instructionCount++;
+					}
+					advanceTimers(); //After 10 instructions, 1/60th of a second has passed.
+					DrawDisplay();
 				}
 			}
 		}
 		if (IsTextEntryEnabled()){
 			DrawStringDecal({2,2},"Goto Memory Address: "+TextEntryGetString());
 		}
+		if (GetKey(F12).bPressed){
+			PAUSED=!PAUSED;
+		}
 
 		std::stringstream s;
 		s<<"PC: 0x"<<std::setfill('0')<< std::setw(4)<<std::hex<<pc;
@@ -190,6 +201,10 @@ public:
 			DrawStringDecal(vi2d{12+i/8*64,EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_HEIGHT+54+i%8*10},s.str());
 		}
 
+		DrawStringDecal(vi2d{8+164,EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_HEIGHT+44},"TIMERS");
+		DrawStringDecal(vi2d{12+164,EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_HEIGHT+54},"DELAY  "+std::to_string(delay_timer));
+		DrawStringDecal(vi2d{12+164,EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_HEIGHT+64},"SOUND  "+std::to_string(sound_timer));
+
 		std::stringstream index_s;
 		index_s<<"0x"<<std::hex<<std::setfill('0')<<std::setw(4)<<index;
 		DrawStringDecal(vi2d{8,EMULATOR_PIXEL_SIZE*EMULATOR_SCREEN_HEIGHT+64+10*8},"INDEX: "+index_s.str());
@@ -364,7 +379,7 @@ public:
 				return jump.str();
 			}break;
 			case 0xC:{//Random number from 0 to NN.
-				return "RAND (0-"+std::to_string(NN)+")";
+				return "RAND (0-"+std::to_string(NN)+") SET TO V"+std::to_string(X);
 			}break;
 			case 0xD:{ //Display
 				return "DISPLAY X:[V"+std::to_string(X)+"],Y:[V"+std::to_string(Y)+"] H:"+std::to_string(N);
@@ -503,10 +518,10 @@ public:
 						reg[0xF]=carryFlag;
 					}break;
 					case 0x5:{// sets VX to the result of VX - VY.
-						bool carryFlag=0;
-						if (reg[X]>reg[Y]){
+						bool carryFlag=false;
+						if (reg[X]>=reg[Y]){
 							//reg[0xF]=1;
-							carryFlag=1;
+							carryFlag=true;
 						}
 						reg[X]-=reg[Y];
 						reg[0xF]=carryFlag;
@@ -527,7 +542,7 @@ public:
 					case 0x7:{//sets VX to the result of VY - VX. It's a reverse subtraction.
 						//reg[0xF]=0;
 						bool carryFlag=false;
-						if (reg[Y]>reg[X]){
+						if (reg[Y]>=reg[X]){
 							//reg[0xF]=1;
 							carryFlag=true;
 						}
@@ -612,13 +627,13 @@ public:
 					}break;
 					case 0x1E:{//The index register I will get the value in VX added to it.
 						//reg[0xF]=0;
-						bool carryFlag=false;
+						/*bool carryFlag=false;
 						if (index+reg[X]>=0x1000){
 							//reg[0xF]=1;
 							carryFlag=true;
-						}
+						}*/
 						index+=reg[X];
-						reg[0xF]=carryFlag;
+						//reg[0xF]=carryFlag;
 					}break;
 					case 0x0A:{//This instruction “blocks”; it stops executing instructions and waits for key input
 						for (int i=0;i<keymap.size();i++){