sigonasr2/CHIP8Emulator
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Fixed the subtraction carryover bug!

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Co-authored-by: sigonasr2 <sigonasr2@gmail.com>
This commit is contained in:
sigonasr2 2023-01-08 19:44:00 -06:00
parent 3f7a94e82f
commit ac0d78a18b
2 changed files with 24 additions and 9 deletions
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main.cpp
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@ -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++){