enums and RTC work

more MBC3 work
MBC3 work
2026-03-18 01:09:03 -07:00 · 2026-03-17 01:46:28 -07:00 · 2026-03-16 23:44:38 -07:00 · 2026-03-16 22:38:31 -07:00 · 2026-03-16 02:50:02 -07:00 · 2026-03-13 18:07:43 -07:00
15 changed files with 5074 additions and 5047 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,7 +19,11 @@ add_executable(GameBoy++ src/main.cpp
        src/testing.hpp
        src/joypad.cpp
 )
+target_compile_options(GameBoy++ PRIVATE -O2)
 target_link_libraries(GameBoy++ ${SDL2_LIBRARIES})
+target_compile_options(GameBoy++ PRIVATE
+    $<$<CONFIG:Release>:-O2>
+)

 if(CMAKE_EXPORT_COMPILE_COMMANDS)
  add_custom_target(copy_compile_commands ALL
--- a/src/addressSpace.cpp
+++ b/src/addressSpace.cpp
@@ -2,17 +2,11 @@
 #include <iostream>
 #include <iterator>

-bool AddressSpace::getBootromState() const {
-	return bootromLoaded;
-}
+bool AddressSpace::getBootromState() const { return bootromLoaded; }

-void AddressSpace::unmapBootrom() {
-	bootromLoaded = false;
-}
+void AddressSpace::unmapBootrom() { bootromLoaded = false; }

-void AddressSpace::mapBootrom() {
-	bootromLoaded = true;
-}
+void AddressSpace::mapBootrom() { bootromLoaded = true; }

 void AddressSpace::loadBootrom(const std::string &filename) {
  std::ifstream file;
@@ -45,8 +39,7 @@ void AddressSpace::loadGame(const std::string& filename) {
  rom.seekg(0, std::ios::beg);

  game.reserve(rom_size);
-	game.insert(game.begin(),
-	            std::istream_iterator<Byte>(rom),
+  game.insert(game.begin(), std::istream_iterator<Byte>(rom),
              std::istream_iterator<Byte>());

  memoryLayout.romBank0 = game.data();
@@ -57,11 +50,10 @@ void AddressSpace::dmaTransfer() {
  dmaTransferRequested = false;
  const Word addr = memoryLayout.DMA << 8;
  for (int i = 0; i < 0xA0; i++) {
-		const Byte data = (*this)[addr + i];;
+    const Byte data = (*this)[addr + i];
+    ;
    (*this)[0xFE00 + i] = data;
  }
 }

-void AddressSpace::setTesting(const bool state) {
-	testing = state;
-}
+void AddressSpace::setTesting(const bool state) { testing = state; }
--- a/src/addressSpace.hpp
+++ b/src/addressSpace.hpp
@@ -1,9 +1,9 @@
 #ifndef ADDRESSSPACE_HPP
 #define ADDRESSSPACE_HPP
-#include <fstream>
-#include <filesystem>
 #include <cstdint>
 #include <cstring>
+#include <filesystem>
+#include <fstream>
 #include <string>
 #include <vector>

@@ -42,7 +42,7 @@ public:
    Byte TMA;
    Byte TAC = 0xF8;
    // interrupt flag and enable
-		Byte IF = 0xE1;;
+    Byte IF = 0xE1;
    // Sound registers
    Byte NR10;
    Byte NR11;
@@ -92,15 +92,17 @@ public:
  void loadGame(const std::string &filename);

  void determineMBCInfo();
-	static bool testMBCWrite(Word address);
-	Byte* MBCRead(Word address);
+  Byte *MBCWrite(Word address);
  // prevents seg faults when programs with no MBC try to write to ROM
  Byte dummyVal = 0;
+
+  // called after every op
  void MBCUpdate();
+
  void loadRomBank();
  void createRamBank();
  void loadRamBank();
-	MBCType MBC = {};
+  MBCType_enum MBC = {};
  uint32_t romSize = 0;
  uint32_t romBanks = 0;
  uint32_t externalRamSize = 0;
@@ -109,17 +111,30 @@ public:
  bool dmaTransferRequested = false;
  void dmaTransfer();

-	//Selected ROM Bank = (Secondary Bank << 5) + ROM Bank
+  // MBC registers
+  // Selected ROM Bank in MBC1 = (Secondary Bank << 5) + ROM Bank
  Byte selectedRomBank = 0;
  Byte romBankRegister = 0x00;
-	//2 bit register acts as secondary rom bank register or ram bank number
+  // 2 bit register acts as secondary rom bank register or ram bank number in
+  // MBC1
  Byte twoBitBankRegister = 0x0;
  Byte selectedExternalRamBank = 0;
  Byte romRamSelect = 0x00;
+  // 0xA if enabled in MBC1/3, else off
+  // in MBC2 also the rom bank number
+  // in MBC3 also timer enable
+  // reading ram while disabled is undefined behaviour
  Byte ramEnable = 0x00;
  // MBC3
  Byte latchClockData = 0x00;
  Byte ramBankRTCRegister = 0x00;
+  // RTC registers
+  enabledRTCRegister_enum enabledRTCRegister = NONE;
+  Byte RTCSeconds = 0x0;
+  Byte RTCMinutes = 0x0;
+  Byte RTCHours = 0x0;
+  Byte RTCDayLower = 0x0;
+  Byte RTCDayHigher = 0x0;

  void setTesting(bool state);

@@ -129,31 +144,47 @@ public:
      return testRam[address];
    if (address < 0x0100 && bootromLoaded)
      return bootrom[address];
-		if (address < 0x4000)
+    else if (address < 0x4000)
      return memoryLayout.romBank0[address];
-		if (address < 0x8000)
+    else if (address < 0x8000)
      return memoryLayout.romBankSwitch[address - 0x4000];
-		if (address < 0xA000)
+    else if (address < 0xA000)
      return memoryLayout.vram[address - 0x8000];
-		if (address < 0xC000) {
+    else if (address < 0xC000) {
+      if (enabledRTCRegister != NONE) {
+        switch (enabledRTCRegister) {
+        case RTCS:
+          return RTCSeconds;
+        case RTCM:
+          return RTCMinutes;
+        case RTCH:
+          return RTCHours;
+        case RTCDL:
+          return RTCDayLower;
+        case RTCDH:
+          return RTCDayHigher;
+        }
+      }
      if (externalRamSize == 0)
        return 0xFF;
+      // MBC2 echos 15 times and only stores lower 4 bits
+      else if (MBC == MBC2 || MBC == MBC2Battery)
+        return memoryLayout.externalRam[(address - 0xA000) & 0x01FF] | 0xF0;
+      else
        return memoryLayout.externalRam[address - 0xA000];
-		}
-		if (address < 0xD000)
+    } else if (address < 0xD000)
      return memoryLayout.memoryBank1[address - 0xC000];
-		if (address < 0xE000)
+    else if (address < 0xE000)
      return memoryLayout.memoryBank2[address - 0xD000];
-		if (address < 0xFE00)
+    else if (address < 0xFE00)
      return memoryLayout.memoryBank1[address - 0xE000];
-		if (address < 0xFEA0)
+    else if (address < 0xFEA0)
      return memoryLayout.oam[address - 0xFE00];
-		if (address < 0xFF00) {
+    else if (address < 0xFF00) {
      if ((memoryLayout.STAT & 0x03) == 2 || (memoryLayout.STAT & 0x03) == 3)
        return 0xFF;
      return 0x00;
-		}
-		if (address < 0xFF80)
+    } else if (address < 0xFF80)
      switch (address) {
      case 0xFF00:
        return memoryLayout.JOYP;
@@ -168,7 +199,7 @@ public:
      case 0xFF06:
        return memoryLayout.TMA;
      case 0xFF07:
-				return memoryLayout.TAC | 0xF8;;
+        return memoryLayout.TAC | 0xF8;
      case 0xFF0F:
        return memoryLayout.IF | 0xE0;
      case 0xFF10:
@@ -223,8 +254,6 @@ public:
      case 0xFF43:
        return memoryLayout.SCX;
      case 0xFF44:
-				//for debugging only
-				//return 0x90;
        return memoryLayout.LY;
      case 0xFF45:
        return memoryLayout.LYC;
@@ -246,7 +275,7 @@ public:
        }
        return 0xFF;
      }
-		if (address < 0xFFFF)
+    else if (address < 0xFFFF)
      return memoryLayout.specialRam[address - 0xFF80];
    // 0xFFFF
    return memoryLayout.IE;
@@ -257,28 +286,27 @@ public:
    dummyVal = 0xFF;
    if (testing)
      return testRam[address];
-		if (address < 0x0100 && bootromLoaded)
+    else if (address < 0x0100 && bootromLoaded)
      return bootrom[address];
-		if (address < 0x8000)
-			return (*MBCRead(address));
-		if (address < 0xA000)
+    else if (address < 0x8000)
+      return (*MBCWrite(address));
+    else if (address < 0xA000)
      return memoryLayout.vram[address - 0x8000];
-		if (address < 0xC000) {
+    else if (address < 0xC000) {
      if (externalRamSize == 0)
        return dummyVal;
      return memoryLayout.externalRam[address - 0xA000];
-		}
-		if (address < 0xD000)
+    } else if (address < 0xD000)
      return memoryLayout.memoryBank1[address - 0xC000];
-		if (address < 0xE000)
+    else if (address < 0xE000)
      return memoryLayout.memoryBank2[address - 0xD000];
-		if (address < 0xFE00)
+    else if (address < 0xFE00)
      return memoryLayout.memoryBank1[address - 0xE000];
-		if (address < 0xFEA0)
+    else if (address < 0xFEA0)
      return memoryLayout.oam[address - 0xFE00];
-		if (address < 0xFF00)
+    else if (address < 0xFF00)
      return memoryLayout.notUsable[address - 0xFEA0];
-		if (address < 0xFF80)
+    else if (address < 0xFF80)
      switch (address) {
      case 0xFF00:
        return memoryLayout.JOYP;
@@ -372,12 +400,11 @@ public:
        }
        return dummyVal;
      }
-		if (address < 0xFFFF)
+    else if (address < 0xFFFF)
      return memoryLayout.specialRam[address - 0xFF80];
    // 0xFFFF
    return memoryLayout.IE;
  }
 };

-
 #endif // ADDRESSSPACE_HPP
--- a/src/defines.hpp
+++ b/src/defines.hpp
@@ -47,7 +47,6 @@
 #define X_FLIP 5
 #define OBJ_PALETTE 4

-
 #define ROM_BANK_SIZE 0x4000
 #define RAM_BANK_SIZE 0x2000

@@ -80,7 +79,7 @@ struct Input {
  bool SELECT = false;
 };

-enum MBCType {
+enum MBCType_enum {
  romOnly = 0x00,
  MBC1 = 0x01,
  MBC1Ram = 0x02,
@@ -95,7 +94,8 @@ enum MBCType {
  MBC3TimerBattery = 0x0F,
  MBC3TimerRamBattery = 0x10,
  MBC3 = 0x11,
-	MBC3Ram = 0x12, // MBC3 with 64 KiB of SRAM refers to MBC30, used only in Pocket Monsters: Crystal Version.
+  MBC3Ram = 0x12, // MBC3 with 64 KiB of SRAM refers to MBC30, used only in
+                  // Pocket Monsters: Crystal Version.
  MBC3RamBattery = 0x13,
  MBC5 = 0x19,
  MBC5Ram = 0x1A,
@@ -111,11 +111,23 @@ enum MBCType {
  HuC1RamBattery = 0xFF
 };

-enum PPUMode {
-	mode0, // Horizontal Blank (Mode 0): No access to video RAM, occurs during horizontal blanking period.
-	mode1, // Vertical Blank (Mode 1): No access to video RAM, occurs during vertical blanking period.
-	mode2, // OAM Search (Mode 2): Access to OAM (Object Attribute Memory) only, sprite evaluation.
-	mode3 // Pixel Transfer (Mode 3): Access to both OAM and video RAM, actual pixel transfer to the screen.
+enum PPUMode_enum {
+  mode0, // Horizontal Blank (Mode 0): No access to video RAM, occurs during
+         // horizontal blanking period.
+  mode1, // Vertical Blank (Mode 1): No access to video RAM, occurs during
+         // vertical blanking period.
+  mode2, // OAM Search (Mode 2): Access to OAM (Object Attribute Memory) only,
+         // sprite evaluation.
+  mode3  // Pixel Transfer (Mode 3): Access to both OAM and video RAM, actual
+         // pixel transfer to the screen.
 };

+enum enabledRTCRegister_enum {
+  NONE = 0x00,
+  RTCS = 0x08,
+  RTCM = 0x09,
+  RTCH = 0x0A,
+  RTCDL = 0x0B,
+  RTCDH = 0x0C
+};
 #endif
--- a/src/extendedOpcodeResolver.cpp
+++ b/src/extendedOpcodeResolver.cpp
@@ -1541,7 +1541,8 @@ void GameBoy::extendedOpcodeResolver() {
    break;

  default:
-		printf("Unsupported extended opcode found: PC:0x%.2x, Opcode:0xcb%.2x\n", PC, addressSpace[PC]);
+    printf("Unsupported extended opcode found: PC:0x%.2x, Opcode:0xcb%.2x\n",
+           PC, addressSpace[PC]);
    exit(1);
  }
 }
--- a/src/gameboy.cpp
+++ b/src/gameboy.cpp
@@ -1,5 +1,5 @@
-#include <iostream>
 #include "gameboy.hpp"
+#include <iostream>

 void GameBoy::addCycles(const uint8_t ticks) {
  cycles += ticks;
@@ -34,17 +34,10 @@ GameboyTestState GameBoy::runTest(GameboyTestState initial) {
  for (const auto &[addr, val] : initial.RAM) {
    returnRAM.emplace_back(addr, addressSpace[addr]);
  }
-	return {
-		PC, SP,
-		AF.hi, AF.lo,
-		BC.hi, BC.lo,
-		DE.hi, DE.lo,
-		HL.hi, HL.lo,
-		returnRAM
-	};
+  return {PC,    SP,    AF.hi, AF.lo, BC.hi,    BC.lo,
+          DE.hi, DE.lo, HL.hi, HL.lo, returnRAM};
 }

-
 void GameBoy::start(const std::string &bootrom, const std::string &game) {
  addressSpace.loadBootrom(bootrom);
  addressSpace.loadGame(game);
@@ -146,35 +139,34 @@ void GameBoy::start(const std::string& bootrom, const std::string& game) {
      prevTMA = addressSpace.memoryLayout.TMA;

      if (debug) {
-				printf(
-					"A: %.2X F: %.2X B: %.2X C: %.2X D: %.2X E: %.2X H: %.2X L: %.2X SP: %.4X PC: 00:%.4X (%.2X %.2X %.2X %.2X)\n",
-					AF.hi, AF.lo, BC.hi, BC.lo, DE.hi, DE.lo, HL.hi, HL.lo, SP, PC, readOnlyAddressSpace[PC],
-					readOnlyAddressSpace[PC + 1], readOnlyAddressSpace[PC + 2], readOnlyAddressSpace[PC + 3]);
+        printf("A: %.2X F: %.2X B: %.2X C: %.2X D: %.2X E: %.2X H: %.2X L: "
+               "%.2X SP: %.4X PC: 00:%.4X (%.2X %.2X %.2X %.2X)\n",
+               AF.hi, AF.lo, BC.hi, BC.lo, DE.hi, DE.lo, HL.hi, HL.lo, SP, PC,
+               readOnlyAddressSpace[PC], readOnlyAddressSpace[PC + 1],
+               readOnlyAddressSpace[PC + 2], readOnlyAddressSpace[PC + 3]);

-
-				// printf("Cycles: %lu, Opcode: 0x%.2x PPU cycles: %lu, PPMode: %d\n", cycles, readOnlyAddressSpace[PC],
+        // printf("Cycles: %lu, Opcode: 0x%.2x PPU cycles: %lu, PPMode: %d\n",
+        // cycles, readOnlyAddressSpace[PC],
        //        cyclesSinceLastScanline(), currentMode);
        // printf("AF:0x%.4x, BC:0x%.4x\n", AF.reg, BC.reg);
        // printf("DE:0x%.4x, HL:0x%.4x\n", DE.reg, HL.reg);
        // printf("IME:%d IF:0x%.2x IE:0x%.2x\n", IME, (*IF), (*IE));
        // printf("PC:0x%.4x, SP:0x%.4x\n", PC, SP);
-				// printf("LCDC:%.2x STAT:0x%.2x LY:%d LYC:%d\n", (*LCDC), (*STAT), (*LY), (*LYC));
-				// printf("\n");
+        // printf("LCDC:%.2x STAT:0x%.2x LY:%d LYC:%d\n", (*LCDC), (*STAT),
+        // (*LY), (*LYC)); printf("\n");
      }

      if (!halted) {
        opcodeResolver();
        addressSpace.MBCUpdate();
-			}
-			else {
+      } else {
        addCycles(4);
      }
      timingHandler();
      interruptHandler();
      if (ppuEnabled) {
        ppuUpdate();
-			}
-			else {
+      } else {
        ppuCycles = 2;
        lastScanline = 0;
        lastRefresh = 0;
--- a/src/gameboy.hpp
+++ b/src/gameboy.hpp
@@ -1,13 +1,13 @@
 #ifndef GBPP_SRC_GAMEBOY_HPP_
 #define GBPP_SRC_GAMEBOY_HPP_

-#include <filesystem>
-#include <cstdint>
-#include <string>
-#include <SDL.h>
-#include "defines.hpp"
 #include "addressSpace.hpp"
+#include "defines.hpp"
 #include "testing.hpp"
+#include <SDL.h>
+#include <cstdint>
+#include <filesystem>
+#include <string>

 union RegisterPair {
  Word reg; // register.reg == (hi << 8) + lo. (hi is more significant than lo)
@@ -21,7 +21,8 @@ union RegisterPair {
 class GameBoy {
  // T-cycles not M-cycles (4 T-cycles = 1 M-cycle)
  uint64_t cycles = 0;
-	//Start at 2 T-cycles https://github.com/Gekkio/mooneye-test-suite/blob/main/acceptance/ppu/lcdon_timing-GS.s
+  // Start at 2 T-cycles
+  // https://github.com/Gekkio/mooneye-test-suite/blob/main/acceptance/ppu/lcdon_timing-GS.s
  uint64_t ppuCycles = 2;
  bool ppuEnabled = false;
  uint16_t lastOpTicks = 0;
@@ -49,7 +50,7 @@ class GameBoy {
  AddressSpace addressSpace;
  const AddressSpace &readOnlyAddressSpace = addressSpace;

-	PPUMode currentMode = PPUMode::mode0;
+  PPUMode_enum currentMode = PPUMode_enum::mode0;
  Byte windowLineCounter = 0;
  int16_t cyclesUntilDMATransfer = 160;

@@ -60,7 +61,8 @@ class GameBoy {
  bool stopped = false;

  // 3 colour channels
-	uint32_t* framebuffer = new uint32_t[RESOLUTION_X * RESOLUTION_Y * SCREEN_BPP];
+  uint32_t *framebuffer =
+      new uint32_t[RESOLUTION_X * RESOLUTION_Y * SCREEN_BPP];
  SDL_Window *screen = nullptr;
  SDL_Renderer *renderer = nullptr;
  SDL_Texture *texture = nullptr;
@@ -84,7 +86,7 @@ class GameBoy {
  void SDL2present();

  void checkPPUMode();
-	void setPPUMode(PPUMode mode);
+  void setPPUMode(PPUMode_enum mode);
  uint64_t cyclesSinceLastScanline() const;
  uint64_t cyclesSinceLastRefresh() const;

@@ -113,43 +115,30 @@ class GameBoy {
  void addCycles(Byte ticks);

  // OPCODE FUNCTIONS
-	template <typename T>
-	void ld(T& dest, T src);
+  template <typename T> void ld(T &dest, T src);
  void ldW(Word destAddr, Word src);
-	template <typename T>
-	void orBitwise(T& dest, T src);
-	template <typename T>
-	void andBitwise(T& dest, T src);
-	template <typename T>
-	void xorBitwise(T& dest, T src);
+  template <typename T> void orBitwise(T &dest, T src);
+  template <typename T> void andBitwise(T &dest, T src);
+  template <typename T> void xorBitwise(T &dest, T src);
  void bit(Byte testBit, Byte reg);
  void extendedOpcodeResolver();
  static void set(uint8_t testBit, uint8_t &reg);
  static void res(uint8_t testBit, uint8_t &reg);
-	template <typename T>
-	void jp(T address);
-	template <typename T>
-	bool jrNZ(T offset);
-	template <class T>
-	bool jrNC(T offset);
-	template <class T>
-	bool jrC(T offset);
-	template <typename T>
-	void inc(T& reg);
-	template <typename T>
-	void call(T address);
+  template <typename T> void jp(T address);
+  template <typename T> bool jrNZ(T offset);
+  template <class T> bool jrNC(T offset);
+  template <class T> bool jrC(T offset);
+  template <typename T> void inc(T &reg);
+  template <typename T> void call(T address);
  void halt();
  void daa();
  void stop();
  void cp(Byte value);
-	template <typename T>
-	void dec(T& reg);
-	template <typename T>
-	bool jrZ(T offset);
+  template <typename T> void dec(T &reg);
+  template <typename T> bool jrZ(T offset);
  void sub(Byte value);
  void sbc(Byte value);
-	template <typename T>
-	void jr(T OFFSET);
+  template <typename T> void jr(T OFFSET);
  void push(Word reg);
  void rl(Byte &reg);
  void sla(Byte &reg);
@@ -162,13 +151,10 @@ class GameBoy {
  void rlc(Byte &reg);
  void rlca();
  void rla();
-	template <typename T>
-	void pop(T& reg);
-	template <typename T>
-	void rst(T address);
+  template <typename T> void pop(T &reg);
+  template <typename T> void rst(T address);
  void ret();
-	template <typename T>
-	void add(T& reg, T value);
+  template <typename T> void add(T &reg, T value);
  void adc(Byte value);
  void cpl();
  void scf();
--- a/src/interupts.cpp
+++ b/src/interupts.cpp
@@ -2,7 +2,8 @@
 #include "gameboy.hpp"

 bool GameBoy::testInterruptEnabled(const Byte interrupt) const {
-	return readOnlyAddressSpace.memoryLayout.IE & static_cast<Byte>(1 << interrupt);
+  return readOnlyAddressSpace.memoryLayout.IE &
+         static_cast<Byte>(1 << interrupt);
 }

 void GameBoy::setInterrupt(const Byte interrupt) {
@@ -16,32 +17,37 @@ void GameBoy::resetInterrupt(const Byte interrupt) {
 }

 void GameBoy::interruptHandler() {
-	if (readOnlyAddressSpace.memoryLayout.IF & static_cast<Byte>(1 << VBLANK_INTERRUPT) && testInterruptEnabled(
-		VBLANK_INTERRUPT)) {
+  if (readOnlyAddressSpace.memoryLayout.IF &
+          static_cast<Byte>(1 << VBLANK_INTERRUPT) &&
+      testInterruptEnabled(VBLANK_INTERRUPT)) {
    if (IME)
      VBlankHandle();
    halted = false;
  }
-	if (readOnlyAddressSpace.memoryLayout.IF & static_cast<Byte>(1 << LCD_STAT_INTERRUPT) && testInterruptEnabled(
-		LCD_STAT_INTERRUPT)) {
+  if (readOnlyAddressSpace.memoryLayout.IF &
+          static_cast<Byte>(1 << LCD_STAT_INTERRUPT) &&
+      testInterruptEnabled(LCD_STAT_INTERRUPT)) {
    if (IME)
      LCDStatHandle();
    halted = false;
  }
-	if (readOnlyAddressSpace.memoryLayout.IF & static_cast<Byte>(1 << TIMER_INTERRUPT) && testInterruptEnabled(
-		TIMER_INTERRUPT)) {
+  if (readOnlyAddressSpace.memoryLayout.IF &
+          static_cast<Byte>(1 << TIMER_INTERRUPT) &&
+      testInterruptEnabled(TIMER_INTERRUPT)) {
    if (IME)
      timerHandle();
    halted = false;
  }
-	if (readOnlyAddressSpace.memoryLayout.IF & static_cast<Byte>(1 << SERIAL_INTERRUPT) && testInterruptEnabled(
-		SERIAL_INTERRUPT)) {
+  if (readOnlyAddressSpace.memoryLayout.IF &
+          static_cast<Byte>(1 << SERIAL_INTERRUPT) &&
+      testInterruptEnabled(SERIAL_INTERRUPT)) {
    if (IME)
      serialHandle();
    halted = false;
  }
-	if (readOnlyAddressSpace.memoryLayout.IF & static_cast<Byte>(1 << JOYPAD_INTERRUPT) && testInterruptEnabled(
-		JOYPAD_INTERRUPT)) {
+  if (readOnlyAddressSpace.memoryLayout.IF &
+          static_cast<Byte>(1 << JOYPAD_INTERRUPT) &&
+      testInterruptEnabled(JOYPAD_INTERRUPT)) {
    if (IME)
      joypadHandle();
    halted = false;
--- a/src/joypad.cpp
+++ b/src/joypad.cpp
@@ -1,5 +1,5 @@
-#include "gameboy.hpp"
 #include "defines.hpp"
+#include "gameboy.hpp"

 void GameBoy::joypadHandler() {
  const Byte joyP = addressSpace.memoryLayout.JOYP;
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,8 +1,8 @@
-#include <string>
-#include <filesystem>
-#include <vector>
 #include "3rdParty/json.hpp"
 #include "gameboy.hpp"
+#include <filesystem>
+#include <string>
+#include <vector>

 namespace fs = std::filesystem;
 using json = nlohmann::json;
@@ -32,7 +32,6 @@ void runJSONTests(GameBoy* gb) {
  for (const auto &entry : fs::directory_iterator(path))
    testFiles.emplace_back(entry.path());

-
  for (const auto &testFile : testFiles) {
    std::ifstream file(testFile);
    std::cout << "Running test: " << testFile << std::endl;
@@ -42,10 +41,10 @@ void runJSONTests(GameBoy* gb) {
      // create state
      std::vector<std::tuple<Word, Byte>> initialRAM;
      for (int i = 0; i < test["initial"]["ram"].size(); i++)
-				initialRAM.emplace_back(test["initial"]["ram"][i][0], test["initial"]["ram"][i][1]);
+        initialRAM.emplace_back(test["initial"]["ram"][i][0],
+                                test["initial"]["ram"][i][1]);

-			GameboyTestState initialState = {
-				test["initial"]["pc"],
+      GameboyTestState initialState = {test["initial"]["pc"],
                                       test["initial"]["sp"],
                                       test["initial"]["a"],
                                       test["initial"]["f"],
@@ -55,8 +54,7 @@ void runJSONTests(GameBoy* gb) {
                                       test["initial"]["e"],
                                       test["initial"]["h"],
                                       test["initial"]["l"],
-				initialRAM
-			};
+                                       initialRAM};

      // run
      GameboyTestState result = gb->runTest(initialState);
@@ -64,10 +62,10 @@ void runJSONTests(GameBoy* gb) {
      // compare new state to expected
      std::vector<std::tuple<Word, Byte>> finalRAM;
      for (int i = 0; i < test["final"]["ram"].size(); i++)
-				finalRAM.emplace_back(test["final"]["ram"][i][0], test["final"]["ram"][i][1]);
+        finalRAM.emplace_back(test["final"]["ram"][i][0],
+                              test["final"]["ram"][i][1]);

-			GameboyTestState finalState = {
-				test["final"]["pc"],
+      GameboyTestState finalState = {test["final"]["pc"],
                                     test["final"]["sp"],
                                     test["final"]["a"],
                                     test["final"]["f"],
@@ -77,8 +75,7 @@ void runJSONTests(GameBoy* gb) {
                                     test["final"]["e"],
                                     test["final"]["h"],
                                     test["final"]["l"],
-				finalRAM
-			};
+                                     finalRAM};

      if (finalState != result) {
        std::cout << "Test " << testFile << " failed!" << std::endl;
--- a/src/mbc.cpp
+++ b/src/mbc.cpp
@@ -1,7 +1,8 @@
 #include "addressSpace.hpp"
+#include "defines.hpp"

 void AddressSpace::determineMBCInfo() {
-	MBC = static_cast<MBCType>(memoryLayout.romBank0[0x147]);
+  MBC = static_cast<MBCType_enum>(memoryLayout.romBank0[0x147]);
  romSize = 32768 * (1 << memoryLayout.romBank0[0x147]);
  romBanks = 1 << (memoryLayout.romBank0[0x147] + 1);

@@ -35,13 +36,7 @@ void AddressSpace::determineMBCInfo() {
  }
 }

-bool AddressSpace::testMBCWrite(const Word address) {
-	if (address <= 0x7FFF)
-		return true;
-	return false;
-}
-
-Byte* AddressSpace::MBCRead(const Word address) {
+Byte *AddressSpace::MBCWrite(const Word address) {
  if (MBC == MBC1) {
    if (address <= 0x1FFF)
      return &ramEnable;
@@ -51,8 +46,7 @@ Byte* AddressSpace::MBCRead(const Word address) {
      return &twoBitBankRegister;
    if (address <= 0x7FFF)
      return &romRamSelect;
-	}
-	if (MBC == MBC1Ram || MBC == MBC1RamBattery) {
+  } else if (MBC == MBC1Ram || MBC == MBC1RamBattery) {
    if (address <= 0x1FFF)
      return &ramEnable;
    // bits 0-4
@@ -63,6 +57,24 @@ Byte* AddressSpace::MBCRead(const Word address) {
    }
    if (address <= 0x7FFF)
      return &romRamSelect;
+  } else if (MBC == MBC2 || MBC == MBC2Battery) {
+    if (address <= 0x3FFF) {
+      if (address & 0x0100)
+        return &romBankRegister;
+      else
+        return &ramEnable;
+    }
+  } else if (MBC == MBC3 || MBC == MBC3TimerBattery) {
+    if (address <= 0x1FFF)
+      return &ramEnable;
+  } else if (MBC == MBC3Ram || MBC == MBC3RamBattery ||
+             MBC == MBC3TimerRamBattery) {
+    if (address <= 0x1FFF)
+      return &ramEnable;
+    if (address <= 0x3FFF)
+      return &romBankRegister;
+    if (address <= 0x5FFF)
+      return &ramBankRTCRegister;
  }
  return &dummyVal;
 }
@@ -72,30 +84,31 @@ void AddressSpace::MBCUpdate() {
  // see: https://gbdev.io/pandocs/MBC1.html
  if (MBC == MBC1) {
    // Selected ROM Bank = (Secondary Bank << 5) + ROM Bank
-		romBankRegister &= 0x1F;
-		twoBitBankRegister &= 0x3;
+    romBankRegister &= 0b11111;
+    twoBitBankRegister &= 0b11;

    // 512 KiB can only have 8KiB of ram
    if (romSize >= 524288) {
      if (romBankRegister == 0)
        selectedRomBank = (twoBitBankRegister << 5) + 1;
      selectedRomBank = (twoBitBankRegister << 5) + romBankRegister;
-		}
-		else {
+    } else {
      if (romBankRegister == 0)
        selectedRomBank = 1;
      else
        selectedRomBank = romBankRegister;
    }
+    if (romBankRegister == 0x20 || romBankRegister == 0x40 ||
+        romBankRegister == 0x60)
+      romBankRegister += 1;
    selectedExternalRamBank = 0;

    loadRomBank();
    loadRamBank();
-	}
-	if (MBC == MBC1Ram || MBC == MBC1RamBattery) {
+  } else if (MBC == MBC1Ram || MBC == MBC1RamBattery) {
    // Selected ROM Bank = (Secondary Bank << 5) + ROM Bank
-		romBankRegister &= 0x1F;
-		twoBitBankRegister &= 0x3;
+    romBankRegister &= 0b11111;
+    twoBitBankRegister &= 0b11;

    // 512 KiB can only have 8KiB of ram
    if (romSize >= 524288) {
@@ -103,14 +116,48 @@ void AddressSpace::MBCUpdate() {
        selectedRomBank = (twoBitBankRegister << 5) + 1;
      selectedRomBank = (twoBitBankRegister << 5) + romBankRegister;
      selectedExternalRamBank = 0;
-		}
-		else {
+    } else {
      if (romBankRegister == 0)
        selectedRomBank = 1;
      else
        selectedRomBank = romBankRegister;
      selectedExternalRamBank = twoBitBankRegister;
    }
+    if (romBankRegister == 0x20 || romBankRegister == 0x40 ||
+        romBankRegister == 0x60)
+      romBankRegister += 1;
+
+    loadRomBank();
+    loadRamBank();
+  } else if (MBC == MBC2 || MBC == MBC2Battery) {
+    selectedRomBank = romBankRegister & 0x0F;
+    selectedExternalRamBank = 0;
+
+    loadRomBank();
+    loadRamBank();
+  } else if (MBC == MBC3 || MBC == MBC3TimerBattery) {
+    selectedRomBank = romBankRegister & 0x7F;
+    selectedExternalRamBank = 0;
+
+    if (MBC == MBC3TimerBattery) {
+      if(ramBankRTCRegister >= 0x8 && ramBankRTCRegister <= 0xC)
+        enabledRTCRegister = static_cast<enabledRTCRegister_enum>(ramBankRTCRegister);
+      else
+        enabledRTCRegister = NONE;
+    }
+    loadRomBank();
+    loadRamBank();
+  } else if (MBC == MBC3Ram || MBC == MBC3RamBattery ||
+             MBC == MBC3TimerRamBattery) {
+    selectedRomBank = romBankRegister & 0x7F;
+    selectedExternalRamBank = ramBankRTCRegister & 0b11;
+
+    if (MBC == MBC3TimerRamBattery) {
+      if(ramBankRTCRegister >= 0x8 && ramBankRTCRegister <= 0xC)
+        enabledRTCRegister = static_cast<enabledRTCRegister_enum>(ramBankRTCRegister);
+      else
+        enabledRTCRegister = NONE;
+    }
    loadRomBank();
    loadRamBank();
  }
@@ -128,8 +175,8 @@ void AddressSpace::createRamBank() {
 }

 void AddressSpace::loadRamBank() {
-	if (cartridgeRam != nullptr)
-		memoryLayout.externalRam = cartridgeRam + (RAM_BANK_SIZE * selectedExternalRamBank);
+  if (cartridgeRam != nullptr) {
+    memoryLayout.externalRam =
+        cartridgeRam + (RAM_BANK_SIZE * selectedExternalRamBank);
+  }
 }
-
-
--- a/src/opcodeResolver.cpp
+++ b/src/opcodeResolver.cpp
@@ -1,16 +1,10 @@
 #include "gameboy.hpp"

-void GameBoy::setFlag(const Byte bit) {
-	AF.lo |= (1 << bit);
-}
+void GameBoy::setFlag(const Byte bit) { AF.lo |= (1 << bit); }

-void GameBoy::resetFlag(const Byte bit) {
-	AF.lo &= ~(1 << bit);
-}
+void GameBoy::resetFlag(const Byte bit) { AF.lo &= ~(1 << bit); }

-bool GameBoy::getFlag(const Byte bit) const {
-	return (AF.lo >> bit) & 1;
-}
+bool GameBoy::getFlag(const Byte bit) const { return (AF.lo >> bit) & 1; }

 Word GameBoy::getWordPC() {
  RegisterPair word = {0};
@@ -22,9 +16,7 @@ Word GameBoy::getWordPC() {
  return word.reg;
 }

-Byte GameBoy::getBytePC() {
-	return readOnlyAddressSpace[PC + 1];
-}
+Byte GameBoy::getBytePC() { return readOnlyAddressSpace[PC + 1]; }

 Word GameBoy::getWordSP() {
  RegisterPair word = {0};
@@ -36,27 +28,22 @@ Word GameBoy::getWordSP() {
  return word.reg;
 }

-Byte GameBoy::getByteSP() {
-	return readOnlyAddressSpace[SP++];
-}
+Byte GameBoy::getByteSP() { return readOnlyAddressSpace[SP++]; }

 void GameBoy::ret() {
  PC = readOnlyAddressSpace[SP++];
  PC |= readOnlyAddressSpace[SP++] << 8;
 }

-template <typename T>
-void GameBoy::ld(T& dest, T src) {
+template <typename T> void GameBoy::ld(T &dest, T src) {
  if constexpr (std::is_same_v<T, Byte>) {
    if (&dest == &addressSpace.memoryLayout.DIV) {
      addressSpace.memoryLayout.DIV = 0x00;
      lastDivUpdate = cycles;
-		}
-		else {
+    } else {
      dest = src;
    }
-	}
-	else {
+  } else {
    // 16-bit register pair write
    dest = src;
  }
@@ -67,8 +54,7 @@ void GameBoy::ldW(const Word destAddr, const Word src) {
  addressSpace[destAddr + 1] = static_cast<Byte>((src & 0xFF00) >> 8);
 }

-template <typename T>
-void GameBoy::add(T& reg, T value) {
+template <typename T> void GameBoy::add(T &reg, T value) {
  if (sizeof(reg) == sizeof(Byte)) {
    if ((((value & 0xF) + (reg & 0xF)) & 0x10) == 0x10)
      setFlag(HALFCARRY_FLAG);
@@ -115,7 +101,6 @@ void GameBoy::adc(const Byte value) {
  else
    resetFlag(CARRY_FLAG);

-
  AF.hi += value + carry;

  if (AF.hi == 0)
@@ -149,7 +134,8 @@ void GameBoy::sbc(const Byte value) {
  const Byte carry = getFlag(CARRY_FLAG) ? 1 : 0;
  const Byte result = AF.hi - value - carry;

-	if ((static_cast<unsigned>(AF.hi) - static_cast<unsigned>(value) - carry) > 0xFF)
+  if ((static_cast<unsigned>(AF.hi) - static_cast<unsigned>(value) - carry) >
+      0xFF)
    setFlag(CARRY_FLAG);
  else
    resetFlag(CARRY_FLAG);
@@ -178,8 +164,7 @@ void GameBoy::daa() {
    if (getFlag(HALFCARRY_FLAG)) {
      AF.hi -= 0x06;
    }
-	}
-	else {
+  } else {
    if (getFlag(CARRY_FLAG) || (AF.hi & 0xFF) > 0x99) {
      AF.hi += 0x60;
      setFlag(CARRY_FLAG);
@@ -196,8 +181,7 @@ void GameBoy::daa() {
  resetFlag(HALFCARRY_FLAG);
 }

-template <typename T>
-void GameBoy::orBitwise(T& dest, T src) {
+template <typename T> void GameBoy::orBitwise(T &dest, T src) {
  dest |= src;

  if (dest == 0)
@@ -210,8 +194,7 @@ void GameBoy::orBitwise(T& dest, T src) {
  resetFlag(CARRY_FLAG);
 }

-template <typename T>
-void GameBoy::andBitwise(T& dest, T src) {
+template <typename T> void GameBoy::andBitwise(T &dest, T src) {
  dest &= src;

  if (dest == 0)
@@ -224,8 +207,7 @@ void GameBoy::andBitwise(T& dest, T src) {
  resetFlag(CARRY_FLAG);
 }

-template <typename T>
-void GameBoy::xorBitwise(T& dest, T src) {
+template <typename T> void GameBoy::xorBitwise(T &dest, T src) {
  dest ^= src;

  if (dest == 0)
@@ -248,70 +230,63 @@ void GameBoy::bit(Byte testBit, Byte reg) {
  setFlag(HALFCARRY_FLAG);
 }

-void GameBoy::set(const Byte testBit, Byte& reg) {
-	reg |= (1 << testBit);
-}
+void GameBoy::set(const Byte testBit, Byte &reg) { reg |= (1 << testBit); }

-void GameBoy::res(const Byte testBit, Byte& reg) {
-	reg &= ~(1 << testBit);
-}
+void GameBoy::res(const Byte testBit, Byte &reg) { reg &= ~(1 << testBit); }

-
-template <typename T>
-void GameBoy::jr(T offset) {
+template <typename T> void GameBoy::jr(T offset) {
  PC += static_cast<int8_t>(offset) + 2; // PC moves 2 from original instruction
 }

-template <typename T>
-bool GameBoy::jrNZ(T offset) {
+template <typename T> bool GameBoy::jrNZ(T offset) {
  bool jumped = false;
  if (!getFlag(ZERO_FLAG)) // if not set
  {
-		PC += static_cast<int8_t>(offset) + 2; //PC moves 2 from the original instruction
+    PC += static_cast<int8_t>(offset) +
+          2; // PC moves 2 from the original instruction
    jumped = true;
  }

  return jumped;
 }

-template <typename T>
-bool GameBoy::jrZ(T offset) {
+template <typename T> bool GameBoy::jrZ(T offset) {
  bool jumped = false;
  if (getFlag(ZERO_FLAG)) // if not set
  {
-		PC += static_cast<int8_t>(offset) + 2; //PC moves 2 from the original instruction
+    PC += static_cast<int8_t>(offset) +
+          2; // PC moves 2 from the original instruction
    jumped = true;
  }

  return jumped;
 }

-template <typename T>
-bool GameBoy::jrNC(T offset) {
+template <typename T> bool GameBoy::jrNC(T offset) {
  bool jumped = false;
  if (!getFlag(CARRY_FLAG)) // if not set
  {
-		PC += static_cast<int8_t>(offset) + 2; //PC moves 2 from the original instruction
+    PC += static_cast<int8_t>(offset) +
+          2; // PC moves 2 from the original instruction
    jumped = true;
  }

  return jumped;
 }

-template <typename T>
-bool GameBoy::jrC(T offset) {
+template <typename T> bool GameBoy::jrC(T offset) {
  bool jumped = false;
  if (getFlag(CARRY_FLAG)) // if not set
  {
-		PC += static_cast<int8_t>(offset) + 2; //PC moves 2 from the original instruction
+    PC += static_cast<int8_t>(offset) +
+          2; // PC moves 2 from the original instruction
    jumped = true;
  }

  return jumped;
 }

-template <typename T>
-void GameBoy::inc(T& reg) {
+template <typename T> void GameBoy::inc(T &reg) {
  reg += 1;

  if (sizeof(reg) == sizeof(Byte)) {
@@ -322,7 +297,8 @@ void GameBoy::inc(T& reg) {

    resetFlag(SUBTRACT_FLAG);

-		//halfcarry test https://robdor.com/2016/08/10/gameboy-emulator-half-carry-flag/
+    // halfcarry test
+    // https://robdor.com/2016/08/10/gameboy-emulator-half-carry-flag/
    if ((reg & 0x0F) == 0)
      setFlag(HALFCARRY_FLAG);
    else
@@ -330,8 +306,7 @@ void GameBoy::inc(T& reg) {
  }
 }

-template <typename T>
-void GameBoy::call(T address) {
+template <typename T> void GameBoy::call(T address) {
  push(PC + 3);
  PC = address;
 }
@@ -355,8 +330,7 @@ void GameBoy::cp(const Byte value) //compare
  setFlag(SUBTRACT_FLAG);
 }

-template <typename T>
-void GameBoy::dec(T& reg) {
+template <typename T> void GameBoy::dec(T &reg) {
  reg -= 1;

  if (sizeof(reg) == sizeof(Byte)) {
@@ -367,7 +341,8 @@ void GameBoy::dec(T& reg) {

    setFlag(SUBTRACT_FLAG);

-		//halfcarry test https://www.reddit.com/r/EmuDev/comments/4clh23/trouble_with_halfcarrycarry_flag/
+    // halfcarry test
+    // https://www.reddit.com/r/EmuDev/comments/4clh23/trouble_with_halfcarrycarry_flag/
    if (0 > (((reg + 1) & 0xf) - (reg & 0xf)))
      setFlag(HALFCARRY_FLAG);
    else
@@ -610,8 +585,7 @@ void GameBoy::srl(Byte& reg) {
  resetFlag(HALFCARRY_FLAG);
 }

-template <typename T>
-void GameBoy::pop(T& reg) {
+template <typename T> void GameBoy::pop(T &reg) {
  reg = getWordSP();
  AF.reg &= 0xFFF0;
 }
@@ -622,13 +596,9 @@ void GameBoy::push(const Word reg) {
  addressSpace[--SP] = reg & 0xFF;
 }

-template <typename T>
-void GameBoy::jp(T address) {
-	PC = address;
-}
+template <typename T> void GameBoy::jp(T address) { PC = address; }

-template <typename T>
-void GameBoy::rst(T address) {
+template <typename T> void GameBoy::rst(T address) {
  PC += 1;
  push(PC);
  PC = address;
@@ -656,9 +626,7 @@ void GameBoy::ccf() {
  resetFlag(HALFCARRY_FLAG);
 }

-void GameBoy::stop() {
-	stopped = true;
-}
+void GameBoy::stop() { stopped = true; }

 void GameBoy::opcodeResolver() {
  if (readOnlyAddressSpace[PC] != 0xCB) {
@@ -859,8 +827,7 @@ void GameBoy::opcodeResolver() {
      jumped = jrNZ(getBytePC());
      if (jumped) {
        addCycles(12);
-			}
-			else {
+      } else {
        PC += 2;
        addCycles(8);
      }
@@ -913,8 +880,7 @@ void GameBoy::opcodeResolver() {
      jumped = jrZ(getBytePC());
      if (jumped) {
        addCycles(12);
-			}
-			else {
+      } else {
        PC += 2;
        addCycles(8);
      }
@@ -967,8 +933,7 @@ void GameBoy::opcodeResolver() {
      jumped = jrNC(getBytePC());
      if (jumped) {
        addCycles(12);
-			}
-			else {
+      } else {
        PC += 2;
        addCycles(8);
      }
@@ -1021,8 +986,7 @@ void GameBoy::opcodeResolver() {
      jumped = jrC(getBytePC());
      if (jumped) {
        addCycles(12);
-			}
-			else {
+      } else {
        PC += 2;
        addCycles(8);
      }
@@ -1843,8 +1807,7 @@ void GameBoy::opcodeResolver() {
      if (!getFlag(ZERO_FLAG)) {
        ret();
        addCycles(20);
-			}
-			else {
+      } else {
        addCycles(8);
        PC += 1;
      }
@@ -1860,8 +1823,7 @@ void GameBoy::opcodeResolver() {
      if (!getFlag(ZERO_FLAG)) {
        jp(getWordPC());
        addCycles(16);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -1876,8 +1838,7 @@ void GameBoy::opcodeResolver() {
      if (!getFlag(ZERO_FLAG)) {
        call(getWordPC());
        addCycles(24);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -1904,8 +1865,7 @@ void GameBoy::opcodeResolver() {
      if (getFlag(ZERO_FLAG)) {
        ret();
        addCycles(20);
-			}
-			else {
+      } else {
        addCycles(8);
        PC += 1;
      }
@@ -1920,8 +1880,7 @@ void GameBoy::opcodeResolver() {
      if (getFlag(ZERO_FLAG)) {
        jp(getWordPC());
        addCycles(16);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -1931,8 +1890,7 @@ void GameBoy::opcodeResolver() {
      if (getFlag(ZERO_FLAG)) {
        call(getWordPC());
        addCycles(24);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -1958,8 +1916,7 @@ void GameBoy::opcodeResolver() {
      if (!getFlag(CARRY_FLAG)) {
        ret();
        addCycles(20);
-			}
-			else {
+      } else {
        addCycles(8);
        PC += 1;
      }
@@ -1975,8 +1932,7 @@ void GameBoy::opcodeResolver() {
      if (!getFlag(CARRY_FLAG)) {
        jp(getWordPC());
        addCycles(24);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -1986,8 +1942,7 @@ void GameBoy::opcodeResolver() {
      if (!getFlag(CARRY_FLAG)) {
        call(getWordPC());
        addCycles(24);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -2014,8 +1969,7 @@ void GameBoy::opcodeResolver() {
      if (getFlag(CARRY_FLAG)) {
        ret();
        addCycles(20);
-			}
-			else {
+      } else {
        addCycles(8);
        PC += 1;
      }
@@ -2032,8 +1986,7 @@ void GameBoy::opcodeResolver() {
      if (getFlag(CARRY_FLAG)) {
        jp(getWordPC());
        addCycles(16);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -2043,8 +1996,7 @@ void GameBoy::opcodeResolver() {
      if (getFlag(CARRY_FLAG)) {
        call(getWordPC());
        addCycles(24);
-			}
-			else {
+      } else {
        addCycles(12);
        PC += 3;
      }
@@ -2096,8 +2048,7 @@ void GameBoy::opcodeResolver() {
      addCycles(16);
      break;

-		case 0xE8:
-			{
+    case 0xE8: {
      const int16_t immediate = static_cast<int8_t>(getBytePC());

      if ((SP & 0xF) + (immediate & 0xF) > 0xF)
@@ -2117,8 +2068,7 @@ void GameBoy::opcodeResolver() {

      PC += 2;
      addCycles(16);
-			}
-			break;
+    } break;

    case 0xE9:
      jp(HL.reg);
@@ -2183,8 +2133,7 @@ void GameBoy::opcodeResolver() {
      addCycles(16);
      break;

-		case 0xF8:
-			{
+    case 0xF8: {
      const int16_t immediate = static_cast<int8_t>(getBytePC());
      HL.reg = SP + immediate;

@@ -2193,20 +2142,17 @@ void GameBoy::opcodeResolver() {
      else
        resetFlag(HALFCARRY_FLAG);

-
      if ((SP & 0xFF) + (immediate & 0xFF) > 0xFF)
        setFlag(CARRY_FLAG);
      else
        resetFlag(CARRY_FLAG);

-
      resetFlag(ZERO_FLAG);
      resetFlag(SUBTRACT_FLAG);

      PC += 2;
      addCycles(12);
-			}
-			break;
+    } break;

    case 0xF9:
      ld(SP, HL.reg);
@@ -2240,10 +2186,10 @@ void GameBoy::opcodeResolver() {
      break;

    default:
-			printf("Unsupported opcode found: PC:0x%.2x, Opcode:0x%.2x\n", PC, addressSpace[PC]);
+      printf("Unsupported opcode found: PC:0x%.2x, Opcode:0x%.2x\n", PC,
+             addressSpace[PC]);
      exit(1);
    }
-	}
-	else
+  } else
    extendedOpcodeResolver();
 }
--- a/src/ppu.cpp
+++ b/src/ppu.cpp
@@ -1,5 +1,5 @@
-#include "gameboy.hpp"
 #include "defines.hpp"
+#include "gameboy.hpp"
 #include <algorithm>
 #include <cstdint>
 #include <iostream>
@@ -33,32 +33,36 @@ void GameBoy::ppuUpdate() {
  checkPPUMode();

  // TODO:
-	// bug on DMG models triggers a STAT interrupt anytime the STAT register is written
-	// Road Rage and Zerd no Denetsu rely on this
+  // bug on DMG models triggers a STAT interrupt anytime the STAT register is
+  // written Road Rage and Zerd no Denetsu rely on this

-	// Check for STAT interrupts and request if needed (e.g., when entering specific modes)
-	const bool hBlankInterruptEnabled = readOnlyAddressSpace.memoryLayout.STAT & (1 << 3);
-	const bool drawingInterruptEnabled = readOnlyAddressSpace.memoryLayout.STAT & (1 << 4);
-	const bool oamInterruptEnabled = readOnlyAddressSpace.memoryLayout.STAT & (1 << 5);
+  // Check for STAT interrupts and request if needed (e.g., when entering
+  // specific modes)
+  const bool hBlankInterruptEnabled =
+      readOnlyAddressSpace.memoryLayout.STAT & (1 << 3);
+  const bool drawingInterruptEnabled =
+      readOnlyAddressSpace.memoryLayout.STAT & (1 << 4);
+  const bool oamInterruptEnabled =
+      readOnlyAddressSpace.memoryLayout.STAT & (1 << 5);
  const bool previousInterruptLine = statInteruptLine;

-	if (currentMode == PPUMode::mode0 && hBlankInterruptEnabled ||
-		currentMode == PPUMode::mode3 && drawingInterruptEnabled ||
-		currentMode == PPUMode::mode2 && oamInterruptEnabled) {
+  if (currentMode == PPUMode_enum::mode0 && hBlankInterruptEnabled ||
+      currentMode == PPUMode_enum::mode3 && drawingInterruptEnabled ||
+      currentMode == PPUMode_enum::mode2 && oamInterruptEnabled) {
    statInteruptLine = true;
-	}
-	else {
+  } else {
    statInteruptLine = false;
  }

-	const bool lyLycInterruptEnabled = readOnlyAddressSpace.memoryLayout.STAT & (1 << 6);
+  const bool lyLycInterruptEnabled =
+      readOnlyAddressSpace.memoryLayout.STAT & (1 << 6);

-	if (readOnlyAddressSpace.memoryLayout.LY == readOnlyAddressSpace.memoryLayout.LYC) {
+  if (readOnlyAddressSpace.memoryLayout.LY ==
+      readOnlyAddressSpace.memoryLayout.LYC) {
    addressSpace.memoryLayout.STAT |= (1 << 2);
    if (lyLycInterruptEnabled)
      statInteruptLine = true;
-	}
-	else {
+  } else {
    addressSpace.memoryLayout.STAT &= ~(1 << 2);
  }
  if (statInteruptLine && !previousInterruptLine)
@@ -80,13 +84,13 @@ void GameBoy::checkPPUMode() {
    break;
  case 2:
    if (cyclesSinceScanline > MODE2_DURATION) {
-			setPPUMode(PPUMode::mode3);
+      setPPUMode(PPUMode_enum::mode3);
    }
    break;
  case 3:
    if (cyclesSinceScanline > MODE2_DURATION + MODE3_MIN_DURATION) {
      drawLine();
-			setPPUMode(PPUMode::mode0);
+      setPPUMode(PPUMode_enum::mode0);
    }
    break;
  }
@@ -94,15 +98,14 @@ void GameBoy::checkPPUMode() {

 void GameBoy::incLY() {
  addressSpace.memoryLayout.LY += 1;
-	setPPUMode(PPUMode::mode2);
+  setPPUMode(PPUMode_enum::mode2);
  if (addressSpace.memoryLayout.LY > SCANLINES_PER_FRAME - 1) {
    addressSpace.memoryLayout.LY = 0;
    windowLineCounter = 0;
-	}
-	else if (addressSpace.memoryLayout.LY == 144) {
+  } else if (addressSpace.memoryLayout.LY == 144) {
    // VBlank Period
    SDL2present();
-		setPPUMode(PPUMode::mode1);
+    setPPUMode(PPUMode_enum::mode1);
    addressSpace.memoryLayout.IF |= 0x1;
  }
 }
@@ -117,7 +120,7 @@ uint64_t GameBoy::cyclesSinceLastRefresh() const {
  return difference;
 }

-void GameBoy::setPPUMode(const PPUMode mode) {
+void GameBoy::setPPUMode(const PPUMode_enum mode) {
  switch (mode) {
  case mode0:
    addressSpace.memoryLayout.STAT &= ~0x03;
@@ -153,18 +156,22 @@ void GameBoy::drawLine() {
  uint32_t *currentLinePixels = framebuffer + lineStartIndex;
  std::fill_n(currentLinePixels, RESOLUTION_X, 0xFFFFFFFF);

-
-	const uint16_t backgroundMapAddr = LCDCBitEnabled(BG_TILE_MAP_AREA) ? 0x9C00 : 0x9800;
-	const uint16_t windowMapAddr = LCDCBitEnabled(WINDOW_TILE_MAP_AREA) ? 0x9C00 : 0x9800;
-	const uint16_t tileDataTableAddr = LCDCBitEnabled(BG_WINDOW_TILE_DATA_AREA) ? 0x8000 : 0x8800;
+  const uint16_t backgroundMapAddr =
+      LCDCBitEnabled(BG_TILE_MAP_AREA) ? 0x9C00 : 0x9800;
+  const uint16_t windowMapAddr =
+      LCDCBitEnabled(WINDOW_TILE_MAP_AREA) ? 0x9C00 : 0x9800;
+  const uint16_t tileDataTableAddr =
+      LCDCBitEnabled(BG_WINDOW_TILE_DATA_AREA) ? 0x8000 : 0x8800;
  const bool signedIndex = !LCDCBitEnabled(BG_WINDOW_TILE_DATA_AREA);

  // BG
  if (LCDCBitEnabled(BG_WINDOW_ENABLE)) {
    for (int pixel = 0; pixel < RESOLUTION_X; pixel++) {
-			const uint16_t xIndex = (pixel + readOnlyAddressSpace.memoryLayout.SCX) % 256;
+      const uint16_t xIndex =
+          (pixel + readOnlyAddressSpace.memoryLayout.SCX) % 256;
      // 256 pixels in total BG width
-			const uint16_t yIndex = (line + readOnlyAddressSpace.memoryLayout.SCY) % 256;
+      const uint16_t yIndex =
+          (line + readOnlyAddressSpace.memoryLayout.SCY) % 256;
      // 256 pixels in total BG height

      const uint16_t tileUpper = (yIndex / 8) << 5;
@@ -172,39 +179,46 @@ void GameBoy::drawLine() {
      const uint16_t tileIndex = tileUpper + tileLower;

      const uint16_t tileAddr = backgroundMapAddr + tileIndex;
-			const int16_t tileID = signedIndex
-				                       ? static_cast<int16_t>(readOnlyAddressSpace[tileAddr])
+      const int16_t tileID =
+          signedIndex ? static_cast<int16_t>(readOnlyAddressSpace[tileAddr])
                      : readOnlyAddressSpace[tileAddr];

      uint16_t tileDataAddr;
      if (signedIndex)
-				tileDataAddr = tileDataTableAddr + (((tileID + 128) % 256) << 4); // For signed, wrap around
+        tileDataAddr = tileDataTableAddr +
+                       (((tileID + 128) % 256) << 4); // For signed, wrap around
      else
        tileDataAddr = tileDataTableAddr + (tileID * 16);

-
      const uint8_t lineOffset = yIndex % 8;
-			const uint8_t tileRowData1 = readOnlyAddressSpace[tileDataAddr + (lineOffset * 2)];
-			const uint8_t tileRowData2 = readOnlyAddressSpace[tileDataAddr + (lineOffset * 2) + 1];
+      const uint8_t tileRowData1 =
+          readOnlyAddressSpace[tileDataAddr + (lineOffset * 2)];
+      const uint8_t tileRowData2 =
+          readOnlyAddressSpace[tileDataAddr + (lineOffset * 2) + 1];

      // get pixel data (2 bits)
      const uint8_t colourBit = 7 - (xIndex % 8);
-			const uint8_t colourNum = ((tileRowData2 >> colourBit) & 0x1) << 1 | ((tileRowData1 >> colourBit) & 0x1);
+      const uint8_t colourNum = ((tileRowData2 >> colourBit) & 0x1) << 1 |
+                                ((tileRowData1 >> colourBit) & 0x1);

      // Apply the BGP register for palette mapping
-			const uint8_t palette = (readOnlyAddressSpace.memoryLayout.BGP >> (colourNum * 2)) & 0x3;
+      const uint8_t palette =
+          (readOnlyAddressSpace.memoryLayout.BGP >> (colourNum * 2)) & 0x3;

      currentLinePixels[pixel] = getColourFromPalette(palette);
    }

-		// 	For the window to be displayed on a scanline, the following conditions must be met:
-		// WY condition was triggered: i.e. at some point in this frame the value of WY was equal to LY (checked at the start of Mode 2 only)
-		// WX condition was triggered: i.e. the current X coordinate being rendered + 7 was equal to WX
-		// Window enable bit in LCDC is set
+    // 	For the window to be displayed on a scanline, the following conditions
+    // must be met: WY condition was triggered: i.e. at some point in this frame
+    // the value of WY was equal to LY (checked at the start of Mode 2 only) WX
+    // condition was triggered: i.e. the current X coordinate being rendered + 7
+    // was equal to WX Window enable bit in LCDC is set
    // Window
    const uint8_t windowY = readOnlyAddressSpace.memoryLayout.WY;
-		const int16_t windowX = static_cast<int16_t>(readOnlyAddressSpace.memoryLayout.WX - 7);
-		if (LCDCBitEnabled(WINDOW_ENABLE) && windowX >= 0 && windowX < RESOLUTION_X && line >= windowY) {
+    const int16_t windowX =
+        static_cast<int16_t>(readOnlyAddressSpace.memoryLayout.WX - 7);
+    if (LCDCBitEnabled(WINDOW_ENABLE) && windowX >= 0 &&
+        windowX < RESOLUTION_X && line >= windowY) {
      for (int pixel = windowX; pixel < RESOLUTION_X; pixel++) {
        const uint16_t yIndex = windowLineCounter;
        const uint16_t windowTileUpper = (yIndex / 8) << 5;
@@ -215,28 +229,31 @@ void GameBoy::drawLine() {
        const uint16_t tileIndex = windowTileUpper + windowTileLower;
        const uint16_t tileAddr = windowMapAddr + tileIndex;

-				const int16_t tileID = signedIndex
-					                       ? static_cast<int16_t>(readOnlyAddressSpace[tileAddr])
+        const int16_t tileID =
+            signedIndex ? static_cast<int16_t>(readOnlyAddressSpace[tileAddr])
                        : readOnlyAddressSpace[tileAddr];

        uint16_t tileDataAddr;
        if (signedIndex)
-					tileDataAddr = tileDataTableAddr + (((tileID + 128) % 256) * 16); // For signed, wrap around
+          tileDataAddr = tileDataTableAddr + (((tileID + 128) % 256) *
+                                              16); // For signed, wrap around
        else
          tileDataAddr = tileDataTableAddr + (tileID * 16);

-
        const uint8_t lineOffset = yIndex % 8;
-				const uint8_t tileRowData1 = readOnlyAddressSpace[tileDataAddr + (lineOffset * 2)];
-				const uint8_t tileRowData2 = readOnlyAddressSpace[tileDataAddr + (lineOffset * 2) + 1];
+        const uint8_t tileRowData1 =
+            readOnlyAddressSpace[tileDataAddr + (lineOffset * 2)];
+        const uint8_t tileRowData2 =
+            readOnlyAddressSpace[tileDataAddr + (lineOffset * 2) + 1];

        // get pixel data (2 bits)
        const uint8_t colourBit = 7 - (xIndex % 8);
-				const uint8_t colourNum = ((tileRowData2 >> colourBit) & 0x1) << 1 | ((tileRowData1 >> colourBit) &
-					0x1);
+        const uint8_t colourNum = ((tileRowData2 >> colourBit) & 0x1) << 1 |
+                                  ((tileRowData1 >> colourBit) & 0x1);

        // Apply the BGP register for palette mapping
-				const uint8_t palette = (readOnlyAddressSpace.memoryLayout.BGP >> (colourNum * 2)) & 0x3;
+        const uint8_t palette =
+            (readOnlyAddressSpace.memoryLayout.BGP >> (colourNum * 2)) & 0x3;

        currentLinePixels[pixel] = getColourFromPalette(palette);
      }
@@ -248,8 +265,7 @@ void GameBoy::drawLine() {
    uint32_t oamPixels[RESOLUTION_X];
    std::fill_n(oamPixels, RESOLUTION_X, 0);

-		constexpr
-			Word oamAddrStart = 0xFE00;
+    constexpr Word oamAddrStart = 0xFE00;
    const int spriteHeight = LCDCBitEnabled(OBJ_SIZE) ? 16 : 8;

    int objects[10] = {0};
@@ -267,7 +283,8 @@ void GameBoy::drawLine() {
      }
    }

-		//sort by xPos (lower has higher priority when rendering) and then earlier objects
+    // sort by xPos (lower has higher priority when rendering) and then earlier
+    // objects
    for (int i = 0; i < found; i++) {
      for (int j = 0; j < found - i - 1; j++) {
        const int xPos1 = readOnlyAddressSpace[objects[j] + 1];
@@ -281,7 +298,6 @@ void GameBoy::drawLine() {
      }
    }

-
    for (int objectIndex = found - 1; objectIndex >= 0; objectIndex--) {
      const int yPos = readOnlyAddressSpace[objects[objectIndex]] - 16;
      const int xPos = readOnlyAddressSpace[objects[objectIndex] + 1] - 8;
@@ -296,9 +312,9 @@ void GameBoy::drawLine() {
                                  ? addressSpace.memoryLayout.OBP1
                                  : addressSpace.memoryLayout.OBP0;

-			for (int pixel = xPos; pixel < RESOLUTION_X && pixel < xPos + 8; pixel++) {
-				constexpr
-					Word objectTileAddr = 0x8000;
+      for (int pixel = xPos; pixel < RESOLUTION_X && pixel < xPos + 8;
+           pixel++) {
+        constexpr Word objectTileAddr = 0x8000;
        if (pixel < 0)
          continue;

@@ -306,8 +322,7 @@ void GameBoy::drawLine() {
        const Byte BGP = readOnlyAddressSpace.memoryLayout.BGP;
        if (priority && (colour == getColourFromPalette((BGP >> 2) & 0x3) ||
                         colour == getColourFromPalette((BGP >> 4) & 0x3) ||
-					colour == getColourFromPalette((BGP >> 6) & 0x3)
-				)) {
+                         colour == getColourFromPalette((BGP >> 6) & 0x3))) {
          oamPixels[pixel] = colour;
          continue;
        }
@@ -319,24 +334,26 @@ void GameBoy::drawLine() {
        if (yFlip)
          objectY = (spriteHeight - 1) - objectY;

-				const Word objTileDataAddr = spriteHeight == 8
-					                             ? objectTileAddr + (tileIndex * 16)
+        const Word objTileDataAddr =
+            spriteHeight == 8 ? objectTileAddr + (tileIndex * 16)
                              : objectTileAddr + ((tileIndex & 0xFE) * 16);

        const Byte tileRow = objectY * 2;
-				const Byte tileRowData1 = readOnlyAddressSpace[objTileDataAddr + tileRow];
-				const Byte tileRowData2 = readOnlyAddressSpace[objTileDataAddr + tileRow + 1];
+        const Byte tileRowData1 =
+            readOnlyAddressSpace[objTileDataAddr + tileRow];
+        const Byte tileRowData2 =
+            readOnlyAddressSpace[objTileDataAddr + tileRow + 1];

        const int bit = 7 - objectX;
-				const int colorIndex = ((tileRowData2 >> bit) & 1) << 1 | ((tileRowData1 >> bit) & 1);
+        const int colorIndex =
+            ((tileRowData2 >> bit) & 1) << 1 | ((tileRowData1 >> bit) & 1);

        // 0 is always transparent
        if (colorIndex != 0) {
          const uint8_t paletteColor = (objPalette >> (colorIndex * 2)) & 0x3;
          const uint32_t finalColor = getColourFromPalette(paletteColor);
          oamPixels[pixel] = finalColor;
-				}
-				else if (oamPixels[pixel] == 0) {
+        } else if (oamPixels[pixel] == 0) {
          oamPixels[pixel] = currentLinePixels[pixel];
        }
      }
@@ -352,17 +369,18 @@ void GameBoy::drawLine() {

 void GameBoy::SDL2setup() {
  SDL_Init(SDL_INIT_EVERYTHING);
-	screen = SDL_CreateWindow("GameBoy++",
-	                          SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
-	                          RESOLUTION_X, RESOLUTION_Y,
-	                          0);
+  screen = SDL_CreateWindow("GameBoy++", SDL_WINDOWPOS_UNDEFINED,
+                            SDL_WINDOWPOS_UNDEFINED, RESOLUTION_X, RESOLUTION_Y,
+                            SDL_WINDOW_RESIZABLE);

  // Create an SDL renderer to draw on the window
-	renderer = SDL_CreateRenderer(screen, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
+  renderer = SDL_CreateRenderer(
+      screen, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);

  // Create an SDL texture to hold the framebuffer data
  texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888,
-	                            SDL_TEXTUREACCESS_STREAMING, RESOLUTION_X, RESOLUTION_Y);
+                              SDL_TEXTUREACCESS_STREAMING, RESOLUTION_X,
+                              RESOLUTION_Y);
 }

 void GameBoy::SDL2destroy() const {
@@ -373,10 +391,11 @@ void GameBoy::SDL2destroy() const {
 }

 void GameBoy::SDL2present() {
-	SDL_UpdateTexture(texture, nullptr, framebuffer, RESOLUTION_X * sizeof(uint32_t));
+  SDL_UpdateTexture(texture, nullptr, framebuffer,
+                    RESOLUTION_X * sizeof(uint32_t));
  SDL_RenderClear(renderer);
  SDL_RenderCopy(renderer, texture, nullptr, nullptr);
-
+  SDL_RenderSetLogicalSize(renderer, RESOLUTION_X, RESOLUTION_Y);

  frameTime = SDL_GetTicks() - frameStart;

--- a/src/testing.hpp
+++ b/src/testing.hpp
@@ -1,13 +1,13 @@
 #ifndef TESTING_HPP
 #define TESTING_HPP

+#include "defines.hpp"
 #include <cstdint>
-#include <vector>
-#include <tuple>
 #include <iostream>
 #include <stdexcept>
 #include <string>
-#include "defines.hpp"
+#include <tuple>
+#include <vector>

 struct GameboyTestState {
  Word PC;
@@ -25,19 +25,15 @@ struct GameboyTestState {
  std::vector<std::tuple<Word, Byte>> RAM;
 };

-inline bool operator==(const GameboyTestState& lhs, const GameboyTestState& rhs) {
+inline bool operator==(const GameboyTestState &lhs,
+                       const GameboyTestState &rhs) {
  for (int i = 0; i < lhs.RAM.size(); i++) {
    if (std::get<1>(lhs.RAM[i]) != std::get<1>(rhs.RAM[i]))
      return false;
  }
-	return (lhs.A == rhs.A &&
-		lhs.F == rhs.F &&
-		lhs.B == rhs.B &&
-		lhs.C == rhs.C &&
-		lhs.D == rhs.D &&
-		lhs.E == rhs.E &&
-		lhs.H == rhs.H &&
-		lhs.L == rhs.L);
+  return (lhs.A == rhs.A && lhs.F == rhs.F && lhs.B == rhs.B &&
+          lhs.C == rhs.C && lhs.D == rhs.D && lhs.E == rhs.E &&
+          lhs.H == rhs.H && lhs.L == rhs.L);
 }

 #endif // TESTING_HPP
--- a/src/timing.cpp
+++ b/src/timing.cpp
@@ -1,9 +1,10 @@
 #include "gameboy.hpp"

-//handles most of the behavoir as described here: https://gbdev.io/pandocs/Timer_and_Divider_Registers.html#ff04--div-divider-register
+// handles most of the behavoir as described here:
+// https://gbdev.io/pandocs/Timer_and_Divider_Registers.html#ff04--div-divider-register
 void GameBoy::timingHandler() {
-	//can't do this as we use cycles for PPU timing but this is what should happen
-	//addressSpace.memoryLayout.DIV = ((cycles / 4) >> 6) & 0xFF;
+  // can't do this as we use cycles for PPU timing but this is what should
+  // happen addressSpace.memoryLayout.DIV = ((cycles / 4) >> 6) & 0xFF;

  if (cycles - lastDivUpdate >= DIVIDER_REGISTER_FREQ) {
    const uint8_t increments = (cycles - lastDivUpdate) / DIVIDER_REGISTER_FREQ;
@@ -28,14 +29,15 @@ void GameBoy::timingHandler() {
      TIMAFrequency = 256;
      break;
    }
-		//if TIMA overflowed and prevTMA != current TMA, use prevTMA (ie use prevTMA regardless)
+    // if TIMA overflowed and prevTMA != current TMA, use prevTMA (ie use
+    // prevTMA regardless)
    const int increments = (cycles - lastTIMAUpdate) / TIMAFrequency;
    if (cycles - lastTIMAUpdate >= TIMAFrequency) {
      if (static_cast<int>(addressSpace.memoryLayout.TIMA) + increments > 255) {
-				addressSpace.memoryLayout.TIMA = prevTMA + ((addressSpace.memoryLayout.TIMA + increments) % 256);
+        addressSpace.memoryLayout.TIMA =
+            prevTMA + ((addressSpace.memoryLayout.TIMA + increments) % 256);
        setInterrupt(TIMER_INTERRUPT);
-			}
-			else
+      } else
        addressSpace.memoryLayout.TIMA += increments;
      lastTIMAUpdate += increments * TIMAFrequency;
    }
Author	SHA1	Message	Date
YayIguess	c242fb7574	enums and RTC work	2026-03-18 01:09:03 -07:00
YayIguess	80e23312de	more MBC3 work	2026-03-17 01:46:28 -07:00
YayIguess	037ba0c76d	MBC3 work	2026-03-16 23:44:38 -07:00
YayIguess	a8ed60259a	resizable window	2026-03-16 22:38:31 -07:00
YayIguess	89e7891249	MBC2 working	2026-03-16 02:50:02 -07:00
YayIguess	3bd1ef34d8	formatting	2026-03-13 18:07:43 -07:00
YayIguess	712ee55e7b	start of mbc3	2026-01-30 16:18:01 -08:00