diff --git a/Source/Project64-core/N64System/Mips/Dma.cpp b/Source/Project64-core/N64System/Mips/Dma.cpp
index 86d7fde61..26d62defa 100644
--- a/Source/Project64-core/N64System/Mips/Dma.cpp
+++ b/Source/Project64-core/N64System/Mips/Dma.cpp
@@ -198,12 +198,8 @@ void CDMA::PI_DMA_READ()
 
 void CDMA::PI_DMA_WRITE()
 {
-    uint32_t PI_WR_LEN_REG = ((g_Reg->PI_WR_LEN_REG) & 0x00FFFFFFul) + 1;
-
-    if ((PI_WR_LEN_REG & 1) != 0)
-    {
-        PI_WR_LEN_REG += 1; /* fixes AI Shougi 3, Doraemon 3, etc. */
-    }
+    uint32_t PI_WR_LEN_REG = ((g_Reg->PI_WR_LEN_REG) & 0x00FFFFFEul) + 2;
+    /* rounding PI_WR_LEN_REG up to the nearest even number fixes AI Shougi 3, Doraemon 3, etc. */
 
     g_Reg->PI_STATUS_REG |= PI_STATUS_DMA_BUSY;
     if (g_Reg->PI_DRAM_ADDR_REG + PI_WR_LEN_REG > g_MMU->RdramSize())
@@ -366,9 +362,63 @@ void CDMA::PI_DMA_WRITE()
         g_Reg->PI_CART_ADDR_REG -= 0x10000000;
         if (g_Reg->PI_CART_ADDR_REG + PI_WR_LEN_REG < g_Rom->GetRomSize())
         {
-            for (i = 0; i < PI_WR_LEN_REG; i++)
+            size_t alignment;
+            RDRAM += g_Reg->PI_DRAM_ADDR_REG;
+            ROM += g_Reg->PI_CART_ADDR_REG;
+            alignment = PI_WR_LEN_REG | (size_t)RDRAM | (size_t)ROM;
+            if ((alignment & 0x3) == 0)
             {
-                *(RDRAM + ((g_Reg->PI_DRAM_ADDR_REG + i) ^ 3)) = *(ROM + ((g_Reg->PI_CART_ADDR_REG + i) ^ 3));
+                for (i = 0; i < PI_WR_LEN_REG; i += 4)
+                {
+                    *(uint32_t *)(RDRAM + i) = *(uint32_t *)(ROM + i);
+                }
+            }
+            else if ((alignment & 1) == 0)
+            {
+                if ((PI_WR_LEN_REG & 2) == 0)
+                {
+                    if (((size_t)RDRAM & 2) == 0)
+                    {
+                        for (i = 0; i < PI_WR_LEN_REG; i += 4)
+                        {
+                            *(uint16_t *)(((size_t)RDRAM + i) + 2) = *(uint16_t *)(((size_t)ROM + i) - 2);
+                            *(uint16_t *)(((size_t)RDRAM + i) + 0) = *(uint16_t *)(((size_t)ROM + i) + 4);
+                        }
+                    }
+                    else
+                    {
+                        if (((size_t)ROM & 2) == 0)
+                        {
+                            for (i = 0; i < PI_WR_LEN_REG; i += 4)
+                            {
+                                *(uint16_t *)(((size_t)RDRAM + i) - 2) = *(uint16_t *)(((size_t)ROM + i) + 2);
+                                *(uint16_t *)(((size_t)RDRAM + i) + 4) = *(uint16_t *)(((size_t)ROM + i) + 0);
+                            }
+                        }
+                        else
+                        {
+                            for (i = 0; i < PI_WR_LEN_REG; i += 4)
+                            {
+                                *(uint16_t *)(((size_t)RDRAM + i) - 2) = *(uint16_t *)(((size_t)ROM + i) - 2);
+                                *(uint16_t *)(((size_t)RDRAM + i) + 4) = *(uint16_t *)(((size_t)ROM + i) + 4);
+                            }
+                        }
+                    }
+                }
+                else
+                {
+                    for (i = 0; i < PI_WR_LEN_REG; i += 2)
+                    {
+                        *(uint16_t *)(((size_t)RDRAM + i) ^ 2) = *(uint16_t *)(((size_t)ROM + i) ^ 2);
+                    }
+                }
+            }
+            else
+            {
+                for (i = 0; i < PI_WR_LEN_REG; i++)
+                {
+                    *(uint8_t *)(((size_t)RDRAM + i) ^ 3) = *(uint8_t *)(((size_t)ROM + i) ^ 3);
+                }
             }
         }
         else if (g_Reg->PI_CART_ADDR_REG >= g_Rom->GetRomSize())
diff --git a/Source/Project64-core/N64System/Mips/RegisterClass.cpp b/Source/Project64-core/N64System/Mips/RegisterClass.cpp
index f0283f6d3..aac7e23a9 100644
--- a/Source/Project64-core/N64System/Mips/RegisterClass.cpp
+++ b/Source/Project64-core/N64System/Mips/RegisterClass.cpp
@@ -307,14 +307,15 @@ void CRegisters::SetAsCurrentSystem()
 
 void CRegisters::CheckInterrupts()
 {
+    uint32_t mi_intr_reg = MI_INTR_REG, status_register;
     if (!m_System->bFixedAudio() && CpuType() != CPU_SyncCores)
     {
-        MI_INTR_REG &= ~MI_INTR_AI;
-        MI_INTR_REG |= (m_AudioIntrReg & MI_INTR_AI);
+        mi_intr_reg &= ~MI_INTR_AI;
+        mi_intr_reg |= (m_AudioIntrReg & MI_INTR_AI);
     }
-    MI_INTR_REG |= (m_RspIntrReg & MI_INTR_SP);
-    MI_INTR_REG |= (m_GfxIntrReg & MI_INTR_DP);
-    if ((MI_INTR_MASK_REG & MI_INTR_REG) != 0)
+    mi_intr_reg |= (m_RspIntrReg & MI_INTR_SP);
+    mi_intr_reg |= (m_GfxIntrReg & MI_INTR_DP);
+    if ((MI_INTR_MASK_REG & mi_intr_reg) != 0)
     {
         FAKE_CAUSE_REGISTER |= CAUSE_IP2;
     }
@@ -322,21 +323,23 @@ void CRegisters::CheckInterrupts()
     {
         FAKE_CAUSE_REGISTER &= ~CAUSE_IP2;
     }
+    MI_INTR_REG = mi_intr_reg;
+    status_register = STATUS_REGISTER;
 
-    if ((STATUS_REGISTER & STATUS_IE) == 0)
+    if ((status_register & STATUS_IE) == 0)
     {
         return;
     }
-    if ((STATUS_REGISTER & STATUS_EXL) != 0)
+    if ((status_register & STATUS_EXL) != 0)
     {
         return;
     }
-    if ((STATUS_REGISTER & STATUS_ERL) != 0)
+    if ((status_register & STATUS_ERL) != 0)
     {
         return;
     }
 
-    if ((STATUS_REGISTER & FAKE_CAUSE_REGISTER & 0xFF00) != 0)
+    if ((status_register & FAKE_CAUSE_REGISTER & 0xFF00) != 0)
     {
         if (m_FirstInterupt)
         {
diff --git a/Source/Project64-core/N64System/Mips/SystemTiming.cpp b/Source/Project64-core/N64System/Mips/SystemTiming.cpp
index 7a749bcc4..22db902b9 100644
--- a/Source/Project64-core/N64System/Mips/SystemTiming.cpp
+++ b/Source/Project64-core/N64System/Mips/SystemTiming.cpp
@@ -161,12 +161,12 @@ void CSystemTimer::UpdateTimers()
     int TimeTaken = m_LastUpdate - m_NextTimer;
     if (TimeTaken != 0)
     {
-        uint32_t random, wired;
+        int32_t random, wired;
         m_LastUpdate = m_NextTimer;
         g_Reg->COUNT_REGISTER += TimeTaken;
         random = g_Reg->RANDOM_REGISTER - (TimeTaken / g_System->CountPerOp());
         wired = g_Reg->WIRED_REGISTER;
-        if ((int)random < (int)wired)
+        if (random < wired)
         {
             if (wired == 0)
             {
@@ -175,10 +175,7 @@ void CSystemTimer::UpdateTimers()
             else
             {
                 uint32_t increment = 32 - wired;
-                do
-                {
-                    random += increment;
-                } while ((int)random < (int)wired);
+                random += ((wired - random + increment - 1) / increment) * increment;
             }
         }
         g_Reg->RANDOM_REGISTER = random;