diff --git a/reactos/lib/fast486/CMakeLists.txt b/reactos/lib/fast486/CMakeLists.txt
index 2fbdb31586f..fd71551de3c 100644
--- a/reactos/lib/fast486/CMakeLists.txt
+++ b/reactos/lib/fast486/CMakeLists.txt
@@ -3,6 +3,7 @@ include_directories(${REACTOS_SOURCE_DIR}/include/reactos/libs/fast486)
 
 list(APPEND SOURCE
     fast486.c
+    fast486dbg.c
     opcodes.c
     opgroups.c
     extraops.c
diff --git a/reactos/lib/fast486/fast486.c b/reactos/lib/fast486/fast486.c
index 51960b7b30f..9c87a1219fd 100644
--- a/reactos/lib/fast486/fast486.c
+++ b/reactos/lib/fast486/fast486.c
@@ -43,7 +43,7 @@ typedef enum
 
 /* PRIVATE FUNCTIONS **********************************************************/
 
-static inline VOID
+VOID
 NTAPI
 Fast486ExecutionControl(PFAST486_STATE State, FAST486_EXEC_CMD Command)
 {
@@ -277,151 +277,6 @@ Fast486Reset(PFAST486_STATE State)
     State->Tlb              = Tlb;
 }
 
-VOID
-NTAPI
-Fast486DumpState(PFAST486_STATE State)
-{
-    DbgPrint("\nFast486DumpState -->\n");
-    DbgPrint("\nCPU currently executing in %s mode at %04X:%08X\n",
-            (State->ControlRegisters[0] & FAST486_CR0_PE) ? "protected" : "real",
-             State->SegmentRegs[FAST486_REG_CS].Selector,
-             State->InstPtr.Long);
-    DbgPrint("\nGeneral purpose registers:\n"
-             "EAX = %08X\tECX = %08X\tEDX = %08X\tEBX = %08X\n"
-             "ESP = %08X\tEBP = %08X\tESI = %08X\tEDI = %08X\n",
-             State->GeneralRegs[FAST486_REG_EAX].Long,
-             State->GeneralRegs[FAST486_REG_ECX].Long,
-             State->GeneralRegs[FAST486_REG_EDX].Long,
-             State->GeneralRegs[FAST486_REG_EBX].Long,
-             State->GeneralRegs[FAST486_REG_ESP].Long,
-             State->GeneralRegs[FAST486_REG_EBP].Long,
-             State->GeneralRegs[FAST486_REG_ESI].Long,
-             State->GeneralRegs[FAST486_REG_EDI].Long);
-    DbgPrint("\nSegment registers:\n"
-             "ES = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
-             "CS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
-             "SS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
-             "DS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
-             "FS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
-             "GS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n",
-             State->SegmentRegs[FAST486_REG_ES].Selector,
-             State->SegmentRegs[FAST486_REG_ES].Base,
-             State->SegmentRegs[FAST486_REG_ES].Limit,
-             State->SegmentRegs[FAST486_REG_ES].Dpl,
-             State->SegmentRegs[FAST486_REG_CS].Selector,
-             State->SegmentRegs[FAST486_REG_CS].Base,
-             State->SegmentRegs[FAST486_REG_CS].Limit,
-             State->SegmentRegs[FAST486_REG_CS].Dpl,
-             State->SegmentRegs[FAST486_REG_SS].Selector,
-             State->SegmentRegs[FAST486_REG_SS].Base,
-             State->SegmentRegs[FAST486_REG_SS].Limit,
-             State->SegmentRegs[FAST486_REG_SS].Dpl,
-             State->SegmentRegs[FAST486_REG_DS].Selector,
-             State->SegmentRegs[FAST486_REG_DS].Base,
-             State->SegmentRegs[FAST486_REG_DS].Limit,
-             State->SegmentRegs[FAST486_REG_DS].Dpl,
-             State->SegmentRegs[FAST486_REG_FS].Selector,
-             State->SegmentRegs[FAST486_REG_FS].Base,
-             State->SegmentRegs[FAST486_REG_FS].Limit,
-             State->SegmentRegs[FAST486_REG_FS].Dpl,
-             State->SegmentRegs[FAST486_REG_GS].Selector,
-             State->SegmentRegs[FAST486_REG_GS].Base,
-             State->SegmentRegs[FAST486_REG_GS].Limit,
-             State->SegmentRegs[FAST486_REG_GS].Dpl);
-    DbgPrint("\nFlags: %08X (%s %s %s %s %s %s %s %s %s %s %s %s %s) Iopl: %u\n",
-             State->Flags.Long,
-             State->Flags.Cf ? "CF" : "cf",
-             State->Flags.Pf ? "PF" : "pf",
-             State->Flags.Af ? "AF" : "af",
-             State->Flags.Zf ? "ZF" : "zf",
-             State->Flags.Sf ? "SF" : "sf",
-             State->Flags.Tf ? "TF" : "tf",
-             State->Flags.If ? "IF" : "if",
-             State->Flags.Df ? "DF" : "df",
-             State->Flags.Of ? "OF" : "of",
-             State->Flags.Nt ? "NT" : "nt",
-             State->Flags.Rf ? "RF" : "rf",
-             State->Flags.Vm ? "VM" : "vm",
-             State->Flags.Ac ? "AC" : "ac",
-             State->Flags.Iopl);
-    DbgPrint("\nControl Registers:\n"
-             "CR0 = %08X\tCR2 = %08X\tCR3 = %08X\n",
-             State->ControlRegisters[FAST486_REG_CR0],
-             State->ControlRegisters[FAST486_REG_CR2],
-             State->ControlRegisters[FAST486_REG_CR3]);
-    DbgPrint("\nDebug Registers:\n"
-             "DR0 = %08X\tDR1 = %08X\tDR2 = %08X\n"
-             "DR3 = %08X\tDR4 = %08X\tDR5 = %08X\n",
-             State->DebugRegisters[FAST486_REG_DR0],
-             State->DebugRegisters[FAST486_REG_DR1],
-             State->DebugRegisters[FAST486_REG_DR2],
-             State->DebugRegisters[FAST486_REG_DR3],
-             State->DebugRegisters[FAST486_REG_DR4],
-             State->DebugRegisters[FAST486_REG_DR5]);
-
-#ifndef FAST486_NO_FPU
-    DbgPrint("\nFPU Registers:\n"
-             "ST0 = %04X%016llX\tST1 = %04X%016llX\n"
-             "ST2 = %04X%016llX\tST3 = %04X%016llX\n"
-             "ST4 = %04X%016llX\tST5 = %04X%016llX\n"
-             "ST6 = %04X%016llX\tST7 = %04X%016llX\n"
-             "Status: %04X\tControl: %04X\tTag: %04X\n",
-             FPU_ST(0).Exponent | ((USHORT)FPU_ST(0).Sign << 15),
-             FPU_ST(0).Mantissa,
-             FPU_ST(1).Exponent | ((USHORT)FPU_ST(1).Sign << 15),
-             FPU_ST(1).Mantissa,
-             FPU_ST(2).Exponent | ((USHORT)FPU_ST(2).Sign << 15),
-             FPU_ST(2).Mantissa,
-             FPU_ST(3).Exponent | ((USHORT)FPU_ST(3).Sign << 15),
-             FPU_ST(3).Mantissa,
-             FPU_ST(4).Exponent | ((USHORT)FPU_ST(4).Sign << 15),
-             FPU_ST(4).Mantissa,
-             FPU_ST(5).Exponent | ((USHORT)FPU_ST(5).Sign << 15),
-             FPU_ST(5).Mantissa,
-             FPU_ST(6).Exponent | ((USHORT)FPU_ST(6).Sign << 15),
-             FPU_ST(6).Mantissa,
-             FPU_ST(7).Exponent | ((USHORT)FPU_ST(7).Sign << 15),
-             FPU_ST(7).Mantissa,
-             State->FpuStatus,
-             State->FpuControl,
-             State->FpuTag);
-#endif
-
-    DbgPrint("\n<-- Fast486DumpState\n\n");
-}
-
-VOID
-NTAPI
-Fast486Continue(PFAST486_STATE State)
-{
-    /* Call the internal function */
-    Fast486ExecutionControl(State, FAST486_CONTINUE);
-}
-
-VOID
-NTAPI
-Fast486StepInto(PFAST486_STATE State)
-{
-    /* Call the internal function */
-    Fast486ExecutionControl(State, FAST486_STEP_INTO);
-}
-
-VOID
-NTAPI
-Fast486StepOver(PFAST486_STATE State)
-{
-    /* Call the internal function */
-    Fast486ExecutionControl(State, FAST486_STEP_OVER);
-}
-
-VOID
-NTAPI
-Fast486StepOut(PFAST486_STATE State)
-{
-    /* Call the internal function */
-    Fast486ExecutionControl(State, FAST486_STEP_OUT);
-}
-
 VOID
 NTAPI
 Fast486Interrupt(PFAST486_STATE State, UCHAR Number)
diff --git a/reactos/lib/fast486/fast486dbg.c b/reactos/lib/fast486/fast486dbg.c
new file mode 100644
index 00000000000..0e1082083e0
--- /dev/null
+++ b/reactos/lib/fast486/fast486dbg.c
@@ -0,0 +1,266 @@
+/*
+ * Fast486 386/486 CPU Emulation Library
+ * fast486dbg.c
+ *
+ * Copyright (C) 2014 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+/* INCLUDES *******************************************************************/
+
+#include <windef.h>
+
+// #define NDEBUG
+#include <debug.h>
+
+#include <fast486.h>
+#include "common.h"
+#include "opcodes.h"
+#include "fpu.h"
+
+/* DEFINES ********************************************************************/
+
+typedef enum
+{
+    FAST486_STEP_INTO,
+    FAST486_STEP_OVER,
+    FAST486_STEP_OUT,
+    FAST486_CONTINUE
+} FAST486_EXEC_CMD;
+
+/* PRIVATE FUNCTIONS **********************************************************/
+
+#if 0
+static inline VOID
+NTAPI
+Fast486ExecutionControl(PFAST486_STATE State, FAST486_EXEC_CMD Command)
+{
+    UCHAR Opcode;
+    FAST486_OPCODE_HANDLER_PROC CurrentHandler;
+    INT ProcedureCallCount = 0;
+
+    /* Main execution loop */
+    do
+    {
+NextInst:
+        /* Check if this is a new instruction */
+        if (State->PrefixFlags == 0) State->SavedInstPtr = State->InstPtr;
+
+        /* Perform an instruction fetch */
+        if (!Fast486FetchByte(State, &Opcode))
+        {
+            /* Exception occurred */
+            State->PrefixFlags = 0;
+            continue;
+        }
+
+        // TODO: Check for CALL/RET to update ProcedureCallCount.
+
+        /* Call the opcode handler */
+        CurrentHandler = Fast486OpcodeHandlers[Opcode];
+        CurrentHandler(State, Opcode);
+
+        /* If this is a prefix, go to the next instruction immediately */
+        if (CurrentHandler == Fast486OpcodePrefix) goto NextInst;
+
+        /* A non-prefix opcode has been executed, reset the prefix flags */
+        State->PrefixFlags = 0;
+
+        /*
+         * Check if there is an interrupt to execute, or a hardware interrupt signal
+         * while interrupts are enabled.
+         */
+        if (State->IntStatus == FAST486_INT_EXECUTE)
+        {
+            /* Perform the interrupt */
+            Fast486PerformInterrupt(State, State->PendingIntNum);
+
+            /* Clear the interrupt status */
+            State->IntStatus = FAST486_INT_NONE;
+        }
+        else if (State->Flags.If && (State->IntStatus == FAST486_INT_SIGNAL)
+                                 && (State->IntAckCallback != NULL))
+        {
+            /* Acknowledge the interrupt to get the number */
+            State->PendingIntNum = State->IntAckCallback(State);
+
+            /* Set the interrupt status to execute on the next instruction */
+            State->IntStatus = FAST486_INT_EXECUTE;
+        }
+        else if (State->IntStatus == FAST486_INT_DELAYED)
+        {
+            /* Restore the old state */
+            State->IntStatus = FAST486_INT_EXECUTE;
+        }
+    }
+    while ((Command == FAST486_CONTINUE) ||
+           (Command == FAST486_STEP_OVER && ProcedureCallCount > 0) ||
+           (Command == FAST486_STEP_OUT && ProcedureCallCount >= 0));
+}
+#else
+VOID
+NTAPI
+Fast486ExecutionControl(PFAST486_STATE State, FAST486_EXEC_CMD Command);
+#endif
+
+/* PUBLIC FUNCTIONS ***********************************************************/
+
+VOID
+NTAPI
+Fast486DumpState(PFAST486_STATE State)
+{
+    DbgPrint("\nFast486DumpState -->\n");
+    DbgPrint("\nCPU currently executing in %s mode at %04X:%08X\n",
+            (State->ControlRegisters[0] & FAST486_CR0_PE) ? "protected" : "real",
+             State->SegmentRegs[FAST486_REG_CS].Selector,
+             State->InstPtr.Long);
+    DbgPrint("\nGeneral purpose registers:\n"
+             "EAX = %08X\tECX = %08X\tEDX = %08X\tEBX = %08X\n"
+             "ESP = %08X\tEBP = %08X\tESI = %08X\tEDI = %08X\n",
+             State->GeneralRegs[FAST486_REG_EAX].Long,
+             State->GeneralRegs[FAST486_REG_ECX].Long,
+             State->GeneralRegs[FAST486_REG_EDX].Long,
+             State->GeneralRegs[FAST486_REG_EBX].Long,
+             State->GeneralRegs[FAST486_REG_ESP].Long,
+             State->GeneralRegs[FAST486_REG_EBP].Long,
+             State->GeneralRegs[FAST486_REG_ESI].Long,
+             State->GeneralRegs[FAST486_REG_EDI].Long);
+    DbgPrint("\nSegment registers:\n"
+             "ES = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
+             "CS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
+             "SS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
+             "DS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
+             "FS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
+             "GS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n",
+             State->SegmentRegs[FAST486_REG_ES].Selector,
+             State->SegmentRegs[FAST486_REG_ES].Base,
+             State->SegmentRegs[FAST486_REG_ES].Limit,
+             State->SegmentRegs[FAST486_REG_ES].Dpl,
+             State->SegmentRegs[FAST486_REG_CS].Selector,
+             State->SegmentRegs[FAST486_REG_CS].Base,
+             State->SegmentRegs[FAST486_REG_CS].Limit,
+             State->SegmentRegs[FAST486_REG_CS].Dpl,
+             State->SegmentRegs[FAST486_REG_SS].Selector,
+             State->SegmentRegs[FAST486_REG_SS].Base,
+             State->SegmentRegs[FAST486_REG_SS].Limit,
+             State->SegmentRegs[FAST486_REG_SS].Dpl,
+             State->SegmentRegs[FAST486_REG_DS].Selector,
+             State->SegmentRegs[FAST486_REG_DS].Base,
+             State->SegmentRegs[FAST486_REG_DS].Limit,
+             State->SegmentRegs[FAST486_REG_DS].Dpl,
+             State->SegmentRegs[FAST486_REG_FS].Selector,
+             State->SegmentRegs[FAST486_REG_FS].Base,
+             State->SegmentRegs[FAST486_REG_FS].Limit,
+             State->SegmentRegs[FAST486_REG_FS].Dpl,
+             State->SegmentRegs[FAST486_REG_GS].Selector,
+             State->SegmentRegs[FAST486_REG_GS].Base,
+             State->SegmentRegs[FAST486_REG_GS].Limit,
+             State->SegmentRegs[FAST486_REG_GS].Dpl);
+    DbgPrint("\nFlags: %08X (%s %s %s %s %s %s %s %s %s %s %s %s %s) Iopl: %u\n",
+             State->Flags.Long,
+             State->Flags.Cf ? "CF" : "cf",
+             State->Flags.Pf ? "PF" : "pf",
+             State->Flags.Af ? "AF" : "af",
+             State->Flags.Zf ? "ZF" : "zf",
+             State->Flags.Sf ? "SF" : "sf",
+             State->Flags.Tf ? "TF" : "tf",
+             State->Flags.If ? "IF" : "if",
+             State->Flags.Df ? "DF" : "df",
+             State->Flags.Of ? "OF" : "of",
+             State->Flags.Nt ? "NT" : "nt",
+             State->Flags.Rf ? "RF" : "rf",
+             State->Flags.Vm ? "VM" : "vm",
+             State->Flags.Ac ? "AC" : "ac",
+             State->Flags.Iopl);
+    DbgPrint("\nControl Registers:\n"
+             "CR0 = %08X\tCR2 = %08X\tCR3 = %08X\n",
+             State->ControlRegisters[FAST486_REG_CR0],
+             State->ControlRegisters[FAST486_REG_CR2],
+             State->ControlRegisters[FAST486_REG_CR3]);
+    DbgPrint("\nDebug Registers:\n"
+             "DR0 = %08X\tDR1 = %08X\tDR2 = %08X\n"
+             "DR3 = %08X\tDR4 = %08X\tDR5 = %08X\n",
+             State->DebugRegisters[FAST486_REG_DR0],
+             State->DebugRegisters[FAST486_REG_DR1],
+             State->DebugRegisters[FAST486_REG_DR2],
+             State->DebugRegisters[FAST486_REG_DR3],
+             State->DebugRegisters[FAST486_REG_DR4],
+             State->DebugRegisters[FAST486_REG_DR5]);
+
+#ifndef FAST486_NO_FPU
+    DbgPrint("\nFPU Registers:\n"
+             "ST0 = %04X%016llX\tST1 = %04X%016llX\n"
+             "ST2 = %04X%016llX\tST3 = %04X%016llX\n"
+             "ST4 = %04X%016llX\tST5 = %04X%016llX\n"
+             "ST6 = %04X%016llX\tST7 = %04X%016llX\n"
+             "Status: %04X\tControl: %04X\tTag: %04X\n",
+             FPU_ST(0).Exponent | ((USHORT)FPU_ST(0).Sign << 15),
+             FPU_ST(0).Mantissa,
+             FPU_ST(1).Exponent | ((USHORT)FPU_ST(1).Sign << 15),
+             FPU_ST(1).Mantissa,
+             FPU_ST(2).Exponent | ((USHORT)FPU_ST(2).Sign << 15),
+             FPU_ST(2).Mantissa,
+             FPU_ST(3).Exponent | ((USHORT)FPU_ST(3).Sign << 15),
+             FPU_ST(3).Mantissa,
+             FPU_ST(4).Exponent | ((USHORT)FPU_ST(4).Sign << 15),
+             FPU_ST(4).Mantissa,
+             FPU_ST(5).Exponent | ((USHORT)FPU_ST(5).Sign << 15),
+             FPU_ST(5).Mantissa,
+             FPU_ST(6).Exponent | ((USHORT)FPU_ST(6).Sign << 15),
+             FPU_ST(6).Mantissa,
+             FPU_ST(7).Exponent | ((USHORT)FPU_ST(7).Sign << 15),
+             FPU_ST(7).Mantissa,
+             State->FpuStatus,
+             State->FpuControl,
+             State->FpuTag);
+#endif
+
+    DbgPrint("\n<-- Fast486DumpState\n\n");
+}
+
+VOID
+NTAPI
+Fast486Continue(PFAST486_STATE State)
+{
+    /* Call the internal function */
+    Fast486ExecutionControl(State, FAST486_CONTINUE);
+}
+
+VOID
+NTAPI
+Fast486StepInto(PFAST486_STATE State)
+{
+    /* Call the internal function */
+    Fast486ExecutionControl(State, FAST486_STEP_INTO);
+}
+
+VOID
+NTAPI
+Fast486StepOver(PFAST486_STATE State)
+{
+    /* Call the internal function */
+    Fast486ExecutionControl(State, FAST486_STEP_OVER);
+}
+
+VOID
+NTAPI
+Fast486StepOut(PFAST486_STATE State)
+{
+    /* Call the internal function */
+    Fast486ExecutionControl(State, FAST486_STEP_OUT);
+}
+
+/* EOF */
diff --git a/reactos/lib/fast486/opcodes.c b/reactos/lib/fast486/opcodes.c
index 1d773f90800..a7199887103 100644
--- a/reactos/lib/fast486/opcodes.c
+++ b/reactos/lib/fast486/opcodes.c
@@ -4630,14 +4630,14 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeInt)
 
     switch (Opcode)
     {
-        case 0xCC:
+        case 0xCC:  // INT 3
         {
             /* This is the INT3 instruction */
             IntNum = 3;
             break;
         }
 
-        case 0xCD:
+        case 0xCD:  // INT xx
         {
             /* Fetch the interrupt number */
             if (!Fast486FetchByte(State, &IntNum))
@@ -4649,7 +4649,7 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeInt)
             break;
         }
 
-        case 0xCE:
+        case 0xCE:  // INTO
         {
             /* Don't do anything if OF is cleared */
             if (!State->Flags.Of) return TRUE;