diff --git a/mbc1.cpp b/mbc1.cpp
index 8ced06b..7b979cf 100644
--- a/mbc1.cpp
+++ b/mbc1.cpp
@@ -9,194 +9,74 @@ namespace mbc1
     #define ROM_BANK_SIZE 0x4000
     #define RAM_BANK_SIZE 0x2000
 
-    uint8_t bootrom[256];
     uint8_t *rom;
-    uint8_t vram[8192];
     uint8_t exram[4 * RAM_BANK_SIZE];
-    uint8_t wram[8192];
-    uint8_t hram[512];
-
-    uint8_t tags[65536];
 
     uint8_t current_rom_bank = 1;
     uint8_t current_ram_bank = 0;
     bool ram_enabled = false;
     bool banking_mode = false; // false = ROM banking mode, true = RAM banking mode
 
-    uint8_t getKeypad(uint8_t value)
-    {
-        const uint8_t *keys = SDL_GetKeyboardState(NULL);
-        value = value & 0xf0;
-        if (value & 0x10) {
-            if (!keys[SDL_SCANCODE_RETURN]) value = value | 0x8;
-            if (!keys[SDL_SCANCODE_SPACE]) value = value | 0x4;
-            if (!keys[SDL_SCANCODE_Z]) value = value | 0x2;
-            if (!keys[SDL_SCANCODE_X]) value = value | 0x1;
-        } else if (value & 0x20) {
-            if (!keys[SDL_SCANCODE_DOWN]) value = value | 0x8;
-            if (!keys[SDL_SCANCODE_UP]) value = value | 0x4;
-            if (!keys[SDL_SCANCODE_LEFT]) value = value | 0x2;
-            if (!keys[SDL_SCANCODE_RIGHT]) value = value | 0x1;
-        } else {
-            value = value | 0x0f;
-        }
-        return value;
-    }
-
-    uint8_t readMem(uint16_t address)
-    {
-        if (address < 0x8000) {
-            if ( (address < 0x0100) && ((hram[0x150]&0x01)==0) ) return bootrom[address];
-            if (address < 0x4000) {
-                // ROM Bank 0
-                return rom[address];
-            } else {
-                // Switchable ROM bank
-                uint32_t banked_address = (current_rom_bank * ROM_BANK_SIZE) + (address - 0x4000);
-                return rom[banked_address];
-            }
-        } else if (address < 0xA000) {
-            return vram[address - 0x8000];
-        } else if (address < 0xC000) {
-            if (ram_enabled) {
-                uint32_t banked_address = (current_ram_bank * RAM_BANK_SIZE) + (address - 0xA000);
-                return exram[banked_address];
-            }
-            return 0xFF; // Return open bus value when RAM is disabled
-        } else if (address < 0xE000) {
-            return wram[address - 0xC000];
-        } else if (address < 0xFE00) {
-            return wram[address - 0xE000];
-        } else {
-            if (address==0xFF00) {
-                hram[address - 0XFE00] = getKeypad(hram[address - 0XFE00]);
-            }
-            return hram[address - 0XFE00];
-        }
-    }
-
-    void writeMem(uint16_t address, uint8_t value)
-    {
-        if (address < 0x8000) {
-            if (address < 0x2000) {
-                // Enable/disable RAM
-                ram_enabled = (value & 0x0F) == 0x0A;
-            } else if (address < 0x4000) {
-                // Select ROM bank
-                value &= 0x1F; // Lower 5 bits are used
-                if (value == 0) value = 1; // Bank 0 is not allowed
-                current_rom_bank = (current_rom_bank & 0x60) | value;
-            } else if (address < 0x6000) {
-                // Select RAM bank or upper bits of ROM bank
-                if (banking_mode) {
-                    current_ram_bank = value & 0x03; // 2 bits for RAM bank
-                } else {
-                    current_rom_bank = (current_rom_bank & 0x1F) | ((value & 0x03) << 5);
-                }
-            } else {
-                // Select banking mode
-                banking_mode = value & 0x01;
-            }
-        } else if (address < 0xA000) {
-            vram[address - 0x8000] = value;
-        } else if (address < 0xC000) {
-            if (ram_enabled) {
-                uint32_t banked_address = (current_ram_bank * RAM_BANK_SIZE) + (address - 0xA000);
-                exram[banked_address] = value;
-            }
-        } else if (address < 0xE000) {
-            wram[address - 0xC000] = value;
-        } else if (address < 0xFE00) {
-            wram[address - 0xE000] = value;
-        } else {
-            if ( (address==0xFF50) && ((value&0x01) != 1) ) return;  //Only allow disabling boot room
-            if ( (address==0xFF00) ) { value = value & 0x30; }
-            if ( (address==0xFF04) ) { hram[address-0xFE00] = 0; return; }
-            if ( (address==0xFF0F) ) { hram[address-0xFE00] = value; sm83::processInterrupts(); return; }
-            if ( (address==0xFF46) ) mem::init_dma_transfer(value);
-            hram[address - 0xFE00] = value;
-        }
-    }
-
-    uint8_t getTag(uint16_t address)
-    {
-        return tags[address];
-    }
-
-    void setTag(uint16_t address, uint8_t value)
-    {
-        tags[address] = value;
-    }
-
-    void saveState(FILE* f)
-    {
-
-    }
-
-    void loadState(FILE *f)
-    {
-
-    }
-
-    uint8_t* rawPtr(uint16_t address)
-    {
-        if (address < 0x8000) {
-            if ( (address < 0x0100) && ((hram[0x150]&0x01)==0) ) return &bootrom[address];
-            if (address < 0x4000) {
-                // ROM Bank 0
-                return &rom[address];
-            } else {
-                // Switchable ROM bank
-                uint32_t banked_address = (current_rom_bank * ROM_BANK_SIZE) + (address - 0x4000);
-                return &rom[banked_address];
-            }
-        } else if (address < 0xA000) {
-            return &vram[address - 0x8000];
-        } else if (address < 0xC000) {
-            if (ram_enabled) {
-                uint32_t banked_address = (current_ram_bank * RAM_BANK_SIZE) + (address - 0xA000);
-                return &exram[banked_address];
-            }
-            return nullptr; // Return open bus value when RAM is disabled
-        } else if (address < 0xE000) {
-            return &wram[address - 0xC000];
-        } else if (address < 0xFE00) {
-            return &wram[address - 0xE000];
-        } else {
-            return &hram[address - 0XFE00];
-        }
-    }
-
     void reset()
     {
-        FILE *f = fopen("dmg_boot.bin", "rb");
-        if (!f) { printf("ABORTING: 'dmg_boot.bin' not found!\n"); exit(1); }
-        fseek(f, 0, SEEK_END);
-        const int size = ftell(f);
-        fseek(f, 0, SEEK_SET);
-        fread(bootrom, size, 1, f);
-        fclose(f);
-
-        for (int i=0; i<8192; ++i) { vram[i] = 0; }
         for (int i=0; i<4*RAM_BANK_SIZE; ++i) { exram[i] = 0; }
-        for (int i=0; i<8192; ++i) { wram[i] = 0; }
-        for (int i=0; i<512; ++i) { hram[i] = 0; }
-        for (int i=0; i<65536; ++i) { tags[i] = MEMTAG_NONE; }
+    }
+
+    uint8_t readRom(uint16_t address)
+    {
+        if (address < 0x4000) {
+            // ROM Bank 0
+            return rom[address];
+        } else {
+            // Switchable ROM bank
+            uint32_t banked_address = (current_rom_bank * ROM_BANK_SIZE) + (address - 0x4000);
+            return rom[banked_address];
+        }
+    }
+
+    void writeRom(uint16_t address, uint8_t value)
+    {
+        if (address < 0x2000) {
+            // Enable/disable RAM
+            ram_enabled = (value & 0x0F) == 0x0A;
+        } else if (address < 0x4000) {
+            // Select ROM bank
+            value &= 0x1F; // Lower 5 bits are used
+            if (value == 0) value = 1; // Bank 0 is not allowed
+            current_rom_bank = (current_rom_bank & 0x60) | value;
+        } else if (address < 0x6000) {
+            // Select RAM bank or upper bits of ROM bank
+            if (banking_mode) {
+                current_ram_bank = value & 0x03; // 2 bits for RAM bank
+            } else {
+                current_rom_bank = (current_rom_bank & 0x1F) | ((value & 0x03) << 5);
+            }
+        } else {
+            // Select banking mode
+            banking_mode = value & 0x01;
+        }
+    }
+
+    uint8_t readRam(uint16_t address)
+    {
+        if (ram_enabled) {
+            uint32_t banked_address = (current_ram_bank * RAM_BANK_SIZE) + (address - 0xa000);
+            return exram[banked_address];
+        }
+        return 0xff; // Return open bus value when RAM is disabled
+    }
+
+    void writeRam(uint16_t address, uint8_t value)
+    {
+        if (ram_enabled) {
+            uint32_t banked_address = (current_ram_bank * RAM_BANK_SIZE) + (address - 0xa000);
+            exram[banked_address] = value;
+        }
     }
 
     void init(uint8_t *rom, uint32_t rom_size, uint32_t ram_size)
     {
-        mem::readMem = mbc1::readMem;
-        mem::writeMem = mbc1::writeMem;
-        mem::getTag = mbc1::getTag;
-        mem::setTag = mbc1::setTag;
-        mem::saveState = mbc1::saveState;
-        mem::loadState = mbc1::loadState;
-        mem::reset = mbc1::reset;
-        mem::rawPtr = mbc1::rawPtr;
-
         mbc1::rom = rom;
-
         reset();
     }
 }
\ No newline at end of file
diff --git a/mbc1.h b/mbc1.h
index 8452049..48ab939 100644
--- a/mbc1.h
+++ b/mbc1.h
@@ -4,4 +4,10 @@
 namespace mbc1
 {
     void init(uint8_t *rom, uint32_t rom_size, uint32_t ram_size);
+
+    void reset();
+    uint8_t readRom(uint16_t address);
+    void writeRom(uint16_t address, uint8_t value);
+    uint8_t readRam(uint16_t address);
+    void writeRam(uint16_t address, uint8_t value);
 }
diff --git a/mbc_none.cpp b/mbc_none.cpp
index c8f2f31..20f2b4e 100644
--- a/mbc_none.cpp
+++ b/mbc_none.cpp
@@ -1,152 +1,22 @@
 #include "mbc_none.h"
-#include "mem.h"
-#include "sm83.h"
-#include <stdlib.h>
-#include <SDL2/SDL.h>
 
 namespace mbc_none
 {
-    uint8_t bootrom[256];
     uint8_t *rom;
-    uint8_t vram[8192];
-    uint8_t exram[8192];
-    uint8_t wram[8192];
-    uint8_t hram[512];
 
-    uint8_t tags[65536];
+    void reset() { } // nothing to do
 
-    uint8_t getKeypad(uint8_t value)
-    {
-        const uint8_t *keys = SDL_GetKeyboardState(NULL);
-        value = value & 0xf0;
-        if (value & 0x10) {
-            if (!keys[SDL_SCANCODE_RETURN]) value = value | 0x8;
-            if (!keys[SDL_SCANCODE_SPACE]) value = value | 0x4;
-            if (!keys[SDL_SCANCODE_Z]) value = value | 0x2;
-            if (!keys[SDL_SCANCODE_X]) value = value | 0x1;
-        } else if (value & 0x20) {
-            if (!keys[SDL_SCANCODE_DOWN]) value = value | 0x8;
-            if (!keys[SDL_SCANCODE_UP]) value = value | 0x4;
-            if (!keys[SDL_SCANCODE_LEFT]) value = value | 0x2;
-            if (!keys[SDL_SCANCODE_RIGHT]) value = value | 0x1;
-        } else {
-            value = value | 0x0f;
-        }
-        return value;
-    }
+    uint8_t readRom(uint16_t address) { return rom[address]; }
 
-    uint8_t readMem(uint16_t address)
-    {
-        if (address < 0x8000) {
-            if ( (address < 0x0100) && ((hram[0x150]&0x01)==0) ) return bootrom[address];
-            return rom[address];
-        } else if (address < 0xA000) {
-            return vram[address - 0x8000];
-        } else if (address < 0xC000) {
-            return exram[address - 0xA000];
-        } else if (address < 0xE000) {
-            return wram[address - 0xC000];
-        } else if (address < 0xFE00) {
-            return wram[address - 0xE000];
-        } else {
-            if (address==0xFF00) {
-                hram[address - 0XFE00] = getKeypad(hram[address - 0XFE00]);
-            }
-            return hram[address - 0XFE00];
-        }
-    }
+    void writeRom(uint16_t address, uint8_t value) { } // do nothing
 
-    void writeMem(uint16_t address, uint8_t value)
-    {
-        if (address < 0x8000) {
-            // Read Only Memory, you know...
-            //rom[address] = value;
-        } else if (address < 0xA000) {
-            vram[address - 0x8000] = value;
-        } else if (address < 0xC000) {
-            exram[address - 0xA000] = value;
-        } else if (address < 0xE000) {
-            wram[address - 0xC000] = value;
-        } else if (address < 0xFE00) {
-            wram[address - 0xE000] = value;
-        } else {
-            if ( (address==0xFF50) && ((value&0x01) != 1) ) return;  //Only allow disabling boot room
-            if ( (address==0xFF00) ) { value = value & 0x30; }
-            if ( (address==0xFF04) ) { hram[address-0xFE00] = 0; return; }
-            if ( (address==0xFF0F) ) { hram[address-0xFE00] = value; sm83::processInterrupts(); return; }
-            if ( (address==0xFF46) ) mem::init_dma_transfer(value);
-            hram[address - 0xFE00] = value;
-        }
-    }
+    uint8_t readRam(uint16_t address) { return 0xff; }
 
-    uint8_t getTag(uint16_t address)
-    {
-        return tags[address];
-    }
-
-    void setTag(uint16_t address, uint8_t value)
-    {
-        tags[address] = value;
-    }
-
-    void saveState(FILE* f)
-    {
-
-    }
-
-    void loadState(FILE *f)
-    {
-
-    }
-
-    uint8_t* rawPtr(uint16_t address)
-    {
-        if (address < 0x8000) {
-            if ( (address < 0x0100) && ((hram[0x150]&0x01)==0) ) return &bootrom[address];
-            return &rom[address];
-        } else if (address < 0xA000) {
-            return &vram[address - 0x8000];
-        } else if (address < 0xC000) {
-            return &exram[address - 0xA000];
-        } else if (address < 0xE000) {
-            return &wram[address - 0xC000];
-        } else if (address < 0xFE00) {
-            return &wram[address - 0xE000];
-        } else {
-            return &hram[address - 0XFE00];
-        }
-    }
-
-    void reset()
-    {
-        FILE *f = fopen("dmg_boot.bin", "rb");
-        if (!f) { printf("ABORTING: 'dmg_boot.bin' not found!\n"); exit(1); }
-        fseek(f, 0, SEEK_END);
-        const int size = ftell(f);
-        fseek(f, 0, SEEK_SET);
-        fread(bootrom, size, 1, f);
-        fclose(f);
-
-        for (int i=0; i<8192; ++i) { vram[i] = 0; }
-        for (int i=0; i<8192; ++i) { exram[i] = 0; }
-        for (int i=0; i<8192; ++i) { wram[i] = 0; }
-        for (int i=0; i<512; ++i) { hram[i] = 0; }
-        for (int i=0; i<65536; ++i) { tags[i] = MEMTAG_NONE; }
-    }
+    void writeRam(uint16_t address, uint8_t value) { } // do nothing
 
     void init(uint8_t *rom, uint32_t rom_size, uint32_t ram_size)
     {
-        mem::readMem = mbc_none::readMem;
-        mem::writeMem = mbc_none::writeMem;
-        mem::getTag = mbc_none::getTag;
-        mem::setTag = mbc_none::setTag;
-        mem::saveState = mbc_none::saveState;
-        mem::loadState = mbc_none::loadState;
-        mem::reset = mbc_none::reset;
-        mem::rawPtr = mbc_none::rawPtr;
-
         mbc_none::rom = rom;
-
         reset();
     }
 }
\ No newline at end of file
diff --git a/mbc_none.h b/mbc_none.h
index be6465f..523d4cc 100644
--- a/mbc_none.h
+++ b/mbc_none.h
@@ -4,4 +4,10 @@
 namespace mbc_none
 {
     void init(uint8_t *rom, uint32_t rom_size, uint32_t ram_size);
+
+    void reset();
+    uint8_t readRom(uint16_t address);
+    void writeRom(uint16_t address, uint8_t value);
+    uint8_t readRam(uint16_t address);
+    void writeRam(uint16_t address, uint8_t value);
 }
diff --git a/mem.cpp b/mem.cpp
index 9ce33e7..ba2a132 100644
--- a/mem.cpp
+++ b/mem.cpp
@@ -2,21 +2,34 @@
 #include "sm83.h"
 #include <stdlib.h>
 #include <stdio.h>
+#include <SDL2/SDL.h>
 
 #include "mbc_none.h"
 #include "mbc1.h"
+
+#define DIV hram[0x104]  // 0xff04 - 0xfe00
+#define TIMA hram[0x105]  // 0xff05 - 0xfe00
+#define TMA hram[0x106]  // 0xff06 - 0xfe00
+#define TAC hram[0x107]  // 0xff07 - 0xfe00
 namespace mem
 {
-    void (*reset)(void);
-    uint8_t(*readMem)(uint16_t);
-    void (*writeMem)(uint16_t, uint8_t);
-    uint8_t(*getTag)(uint16_t);
-    void (*setTag)(uint16_t, uint8_t);
-    void (*saveState)(FILE*);
-    void (*loadState)(FILE*);
-    uint8_t*(*rawPtr)(uint16_t);
-    
+    void (*resetMbc)(void);
+    uint8_t (*readRom)(uint16_t);
+    void (*writeRom)(uint16_t, uint8_t);
+    uint8_t (*readRam)(uint16_t);
+    void (*writeRam)(uint16_t, uint8_t);
+
+    uint8_t bootrom[256];
+    uint8_t *rom;
+    uint8_t vram[8192];
+    uint8_t wram[8192];
+    uint8_t hram[512];
+
+    uint8_t tags[65536];
+
     char *title = nullptr;
+    uint32_t rom_size = 0;
+    uint32_t ram_size = 0;
 
     uint16_t dma_address = 0;
     uint8_t dma_pos = 160;
@@ -27,27 +40,142 @@ namespace mem
 
     void init(uint8_t* rom, const int size)
     {
-        //if (memory) free(memory);
-        //memory = (uint8_t*)malloc(size);
         title = (char*)&rom[0x134];
         uint8_t mapper_type = rom[0x147];
-        uint32_t rom_size = 32768 * (1 << rom[0x148]);
+        rom_size = 32768 * (1 << rom[0x148]);
         int sizes[] = { 0, 0, 8, 32, 128, 64};
-        uint32_t ram_size = sizes[rom[0x149]] * 1024;
+        ram_size = sizes[rom[0x149]] * 1024;
 
         switch (mapper_type)
         {
             case 0x00:
                 mbc_none::init(rom, rom_size, ram_size);
+                mem::resetMbc = mbc_none::reset;
+                mem::readRom = mbc_none::readRom;
+                mem::writeRom = mbc_none::writeRom;
+                mem::readRam = mbc_none::readRam;
+                mem::writeRam = mbc_none::writeRam;
                 break;
             case 0x01:
             case 0x02:
             case 0x03:
                 mbc1::init(rom, rom_size, ram_size);
+                mem::resetMbc = mbc1::reset;
+                mem::readRom = mbc1::readRom;
+                mem::writeRom = mbc1::writeRom;
+                mem::readRam = mbc1::readRam;
+                mem::writeRam = mbc1::writeRam;
                 break;
         };
     }
 
+    void reset()
+    {
+        FILE *f = fopen("dmg_boot.bin", "rb");
+        if (!f) { printf("ABORTING: 'dmg_boot.bin' not found!\n"); exit(1); }
+        fseek(f, 0, SEEK_END);
+        const int size = ftell(f);
+        fseek(f, 0, SEEK_SET);
+        fread(bootrom, size, 1, f);
+        fclose(f);
+
+        for (int i=0; i<8192; ++i) { vram[i] = 0; }
+        for (int i=0; i<8192; ++i) { wram[i] = 0; }
+        for (int i=0; i<512; ++i) { hram[i] = 0; }
+        for (int i=0; i<65536; ++i) { tags[i] = MEMTAG_NONE; }
+
+        resetMbc();
+    }
+
+    uint8_t getKeypad(uint8_t value)
+    {
+        const uint8_t *keys = SDL_GetKeyboardState(NULL);
+        value = value & 0xf0;
+        if (value & 0x10) {
+            if (!keys[SDL_SCANCODE_RETURN]) value = value | 0x8;
+            if (!keys[SDL_SCANCODE_SPACE]) value = value | 0x4;
+            if (!keys[SDL_SCANCODE_Z]) value = value | 0x2;
+            if (!keys[SDL_SCANCODE_X]) value = value | 0x1;
+        } else if (value & 0x20) {
+            if (!keys[SDL_SCANCODE_DOWN]) value = value | 0x8;
+            if (!keys[SDL_SCANCODE_UP]) value = value | 0x4;
+            if (!keys[SDL_SCANCODE_LEFT]) value = value | 0x2;
+            if (!keys[SDL_SCANCODE_RIGHT]) value = value | 0x1;
+        } else {
+            value = value | 0x0f;
+        }
+        return value;
+    }
+
+    uint8_t readMem(uint16_t address)
+    {
+        if (address < 0x8000) {
+            if ( (address < 0x0100) && ((hram[0x150]&0x01)==0) ) return bootrom[address];
+            return readRom(address);
+        } else if (address < 0xA000) {
+            return vram[address - 0x8000];
+        } else if (address < 0xC000) {
+            return readRam(address);
+        } else if (address < 0xE000) {
+            return wram[address - 0xC000];
+        } else if (address < 0xFE00) {
+            return wram[address - 0xE000];
+        } else {
+            if (address==0xFF00) {
+                hram[address - 0XFE00] = getKeypad(hram[address - 0XFE00]);
+            }
+            return hram[address - 0XFE00];
+        }
+    }
+
+    void writeMem(uint16_t address, uint8_t value)
+    {
+        if (address < 0x8000) {
+            writeRom(address, value);
+        } else if (address < 0xA000) {
+            vram[address - 0x8000] = value;
+        } else if (address < 0xC000) {
+            writeRam(address, value);
+        } else if (address < 0xE000) {
+            wram[address - 0xC000] = value;
+        } else if (address < 0xFE00) {
+            wram[address - 0xE000] = value;
+        } else {
+            if ( (address==0xFF50) && ((value&0x01) != 1) ) return;  //Only allow disabling boot room
+            if ( (address==0xFF00) ) { value = value & 0x30; }
+            if ( (address==0xFF04) ) { hram[address-0xFE00] = 0; return; }
+            if ( (address==0xFF0F) ) { hram[address-0xFE00] = value; sm83::processInterrupts(); return; }
+            if ( (address==0xFF46) ) mem::init_dma_transfer(value);
+            hram[address - 0xFE00] = value;
+        }
+    }
+
+    uint8_t getTag(uint16_t address)
+    {
+        return tags[address];
+    }
+
+    void setTag(uint16_t address, uint8_t value)
+    {
+        tags[address] = value;
+    }
+
+    void saveState(FILE* f)
+    {
+
+    }
+
+    void loadState(FILE* f)
+    {
+
+    }
+
+    uint8_t *rawPtr(uint16_t address)
+    {
+        return &hram[address-0xfe00];
+    }
+
+
     void init_dma_transfer(uint8_t source)
     {
         dma_address = source << 8;
@@ -62,21 +190,19 @@ namespace mem
         div_counter += dt;
         if (div_counter>=256) {
             div_counter -= 256;
-            uint8_t *div = mem::rawPtr(0xff04);
-            *div = *div + 1;
+            DIV++;
         }
         
         // Timer
-        uint8_t *t_regs = mem::rawPtr(0xff05);
-        if (*(t_regs+2)&0x4) { // if bit 3 of mem(0xff07) is 1, timer enabled
-            uint16_t freq = timer_frequencies[*(t_regs+2)&0x03];
+        if (TAC&0x4) { // if bit 3 of mem(0xff07) is 1, timer enabled
+            uint16_t freq = timer_frequencies[TAC&0x03];
             timer_counter += dt;
             if (timer_counter>=freq) {
                 timer_counter -= freq;
-                if ((*t_regs)<255)
-                    (*t_regs)++;
+                if (TIMA<255)
+                    TIMA++;
                 else {
-                    *t_regs = *(t_regs+1);
+                    TIMA = TMA;
                     sm83::interrupt(INTERRUPT_TIMER);
                 }
             }
@@ -88,7 +214,7 @@ namespace mem
             dma_dots += dt;
             while (dma_dots >= 4 && dma_pos<160) {
                 dma_dots -= 4;
-                mem::writeMem(0xfe00|dma_pos, mem::readMem(dma_address|dma_pos));
+                hram[dma_pos] = mem::readMem(dma_address|dma_pos);
                 dma_pos++;
             }
         }
diff --git a/mem.h b/mem.h
index 1ce6bab..603b9eb 100644
--- a/mem.h
+++ b/mem.h
@@ -25,18 +25,18 @@ namespace mem
     #define MBC7         7
     
     void init(uint8_t* rom, const int size);
-    extern void (*reset)(void);
+    void reset();
     
-    extern uint8_t(*readMem)(uint16_t);
-    extern void (*writeMem)(uint16_t, uint8_t);
+    uint8_t readMem(uint16_t address);
+    void writeMem(uint16_t address, uint8_t value);
 
-    extern uint8_t(*getTag)(uint16_t);
-    extern void (*setTag)(uint16_t, uint8_t);
+    uint8_t getTag(uint16_t address);
+    void setTag(uint16_t address, uint8_t value);
 
-    extern void (*saveState)(FILE*);
-    extern void (*loadState)(FILE*);
+    void saveState(FILE* f);
+    void loadState(FILE* f);
 
-    extern uint8_t*(*rawPtr)(uint16_t);
+    uint8_t *rawPtr(uint16_t address);
 
     void init_dma_transfer(uint8_t source);
     void update_mapped(const uint32_t dt);
diff --git a/sm83.cpp b/sm83.cpp
index 06344f6..b5630ca 100644
--- a/sm83.cpp
+++ b/sm83.cpp
@@ -592,9 +592,9 @@ namespace sm83
     void HALT()
     {
         if (!halted) {
-            uint8_t *IE = mem::rawPtr(0xffff);
-            uint8_t *IF = mem::rawPtr(0xff0f);
-            if ( (ime==0) && ((*IF & *IE) != 0) ) {
+            const uint8_t IE = mem::readMem(0xffff);
+            const uint8_t IF = mem::readMem(0xff0f);
+            if ( (ime==0) && ((IF & IE) != 0) ) {
                 // [TODO] HALT BUG
                 if (pending_ei==2) rPC--;
                 return;