diff --git a/include/cpu.h b/include/cpu.h
index 20f25870..6a1bb85c 100644
--- a/include/cpu.h
+++ b/include/cpu.h
@@ -29,12 +29,19 @@
 #include "mem.h"
 #endif
 
+#define CPU_AUTODETERMINE_NONE		0x00
+#define CPU_AUTODETERMINE_CORE		0x01
+#define CPU_AUTODETERMINE_CYCLES	0x02
+
+#define CPU_AUTODETERMINE_SHIFT		0x02
+#define CPU_AUTODETERMINE_MASK		0x03
+
 /* CPU Cycle Timing */
 extern Bits CPU_Cycles;
 extern Bits CPU_CycleLeft;
 extern Bits CPU_CycleMax;
 extern bool CPU_CycleAutoAdjust;
-extern bool CPU_AutoDetermineMode;
+extern Bitu CPU_AutoDetermineMode;
 
 /* Some common Defines */
 /* A CPU Handler */
diff --git a/src/cpu/cpu.cpp b/src/cpu/cpu.cpp
index 719e36e1..edae46ef 100644
--- a/src/cpu/cpu.cpp
+++ b/src/cpu/cpu.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: cpu.cpp,v 1.82 2006-06-25 18:49:32 c2woody Exp $ */
+/* $Id: cpu.cpp,v 1.83 2006-06-29 09:10:09 c2woody Exp $ */
 
 #include <assert.h>
 #include "dosbox.h"
@@ -47,7 +47,7 @@ Bits CPU_CycleUp = 0;
 Bits CPU_CycleDown = 0;
 CPU_Decoder * cpudecoder;
 bool CPU_CycleAutoAdjust;
-bool CPU_AutoDetermineMode;
+Bitu CPU_AutoDetermineMode;
 
 void CPU_Core_Full_Init(void);
 void CPU_Core_Normal_Init(void);
@@ -1441,17 +1441,21 @@ void CPU_SET_CRX(Bitu cr,Bitu value) {
 				LOG(LOG_CPU,LOG_NORMAL)("Protected mode");
 				PAGING_Enable((value & CR0_PAGING)>0);
 
-				if (!CPU_AutoDetermineMode) break;
+				if (!(CPU_AutoDetermineMode&CPU_AUTODETERMINE_MASK)) break;
 
-				CPU_AutoDetermineMode=false;
-				CPU_CycleAutoAdjust=true;
-				CPU_CycleLeft=0;
-				CPU_Cycles=0;
-				CPU_CycleMax=0;
-/* #if (C_DYNAMIC_X86)
-				CPU_Core_Dyn_X86_Cache_Init(true);
-				cpudecoder=&CPU_Core_Dyn_X86_Run;
-#endif */
+				if (CPU_AutoDetermineMode&CPU_AUTODETERMINE_CYCLES) {
+					CPU_CycleAutoAdjust=true;
+					CPU_CycleLeft=0;
+					CPU_Cycles=0;
+					CPU_CycleMax=0;
+				}
+ #if (C_DYNAMIC_X86)
+				if (CPU_AutoDetermineMode&CPU_AUTODETERMINE_CORE) {
+					CPU_Core_Dyn_X86_Cache_Init(true);
+					cpudecoder=&CPU_Core_Dyn_X86_Run;
+				}
+#endif
+				CPU_AutoDetermineMode<<=CPU_AUTODETERMINE_SHIFT;
 				GFX_SetTitle(-1,-1,false);
 			} else {
 				cpu.pmode=false;
@@ -1989,16 +1993,20 @@ public:
 	}
 	bool Change_Config(Section* newconfig){
 		Section_prop * section=static_cast<Section_prop *>(newconfig);
+		CPU_AutoDetermineMode=CPU_AUTODETERMINE_NONE;
 		CPU_CycleLeft=0;//needed ?
 		CPU_Cycles=0;
 		const char *cyclesLine = section->Get_string("cycles");
-		CPU_AutoDetermineMode=false;
 		if (!strcasecmp(cyclesLine,"max")) {
 			CPU_CycleMax=0;
 			CPU_CycleAutoAdjust=true;
 		} else {
-			if (!strcasecmp(cyclesLine,"auto")) CPU_AutoDetermineMode=true;
-			CPU_CycleMax=atoi(cyclesLine);
+			if (!strcasecmp(cyclesLine,"auto")) {
+				CPU_AutoDetermineMode|=CPU_AUTODETERMINE_CYCLES;
+				CPU_CycleMax=3000;
+			} else {
+				CPU_CycleMax=atoi(cyclesLine);
+			}
 			CPU_CycleAutoAdjust=false;
 		}
 		CPU_CycleUp=section->Get_int("cycleup");
@@ -2015,6 +2023,9 @@ public:
 #if (C_DYNAMIC_X86)
 		else if (!strcasecmp(core,"dynamic")) {
 			cpudecoder=&CPU_Core_Dyn_X86_Run;
+		} else if (!strcasecmp(core,"auto")) {
+			cpudecoder=&CPU_Core_Normal_Run;
+			CPU_AutoDetermineMode|=CPU_AUTODETERMINE_CORE;
 		} 
 #endif
 		else {
diff --git a/src/dos/dos_execute.cpp b/src/dos/dos_execute.cpp
index c7acbae6..e938537d 100644
--- a/src/dos/dos_execute.cpp
+++ b/src/dos/dos_execute.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: dos_execute.cpp,v 1.55 2006-04-08 11:25:41 qbix79 Exp $ */
+/* $Id: dos_execute.cpp,v 1.56 2006-06-29 09:10:09 c2woody Exp $ */
 
 #include <string.h>
 #include <ctype.h>
@@ -26,6 +26,7 @@
 #include "regs.h"
 #include "callback.h"
 #include "debug.h"
+#include "cpu.h"
 
 const char * RunningProgram="DOSBOX";
 
@@ -137,6 +138,25 @@ bool DOS_Terminate(bool tsr) {
 	// Free memory owned by process
 	if (!tsr) DOS_FreeProcessMemory(mempsp);
 	DOS_UpdatePSPName();
+
+	if ((!(CPU_AutoDetermineMode>>CPU_AUTODETERMINE_SHIFT)) || (cpu.pmode)) return true;
+
+	CPU_AutoDetermineMode>>=CPU_AUTODETERMINE_SHIFT;
+	if (CPU_AutoDetermineMode&CPU_AUTODETERMINE_CYCLES) {
+		CPU_CycleAutoAdjust=false;
+		CPU_CycleLeft=0;
+		CPU_Cycles=0;
+		CPU_CycleMax=3000;
+	}
+ #if (C_DYNAMIC_X86)
+	if (CPU_AutoDetermineMode&CPU_AUTODETERMINE_CORE) {
+		cpudecoder=&CPU_Core_Normal_Run;
+		CPU_CycleLeft=0;
+		CPU_Cycles=0;
+	}
+#endif
+	GFX_SetTitle(-1,-1,false);
+
 	return true;
 }
 
diff --git a/src/dosbox.cpp b/src/dosbox.cpp
index 2cd62f02..47c746c6 100644
--- a/src/dosbox.cpp
+++ b/src/dosbox.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: dosbox.cpp,v 1.100 2006-06-25 18:49:32 c2woody Exp $ */
+/* $Id: dosbox.cpp,v 1.101 2006-06-29 09:10:10 c2woody Exp $ */
 
 #include <stdlib.h>
 #include <stdarg.h>
@@ -282,7 +282,8 @@ void DOSBOX_Init(void) {
 	MSG_Add("CPU_CONFIGFILE_HELP",
 		"core -- CPU Core used in emulation: simple,normal,full"
 #if (C_DYNAMIC_X86)
-		",dynamic"
+		",dynamic,auto.\n"
+		"        auto switches from normal to dynamic if appropriate"
 #endif
 		".\n"
 		"cycles -- Amount of instructions dosbox tries to emulate each millisecond.\n"