diff --git a/include/cpu.h b/include/cpu.h
index f8429d7d..16e0d4ca 100644
--- a/include/cpu.h
+++ b/include/cpu.h
@@ -43,6 +43,7 @@ extern Bit32s CPU_CycleMax;
 extern Bit32s CPU_OldCycleMax;
 extern Bit32s CPU_CyclePercUsed;
 extern Bit32s CPU_CycleLimit;
+extern Bit64s CPU_IODelayRemoved;
 extern bool CPU_CycleAutoAdjust;
 extern Bitu CPU_AutoDetermineMode;
 
diff --git a/src/cpu/cpu.cpp b/src/cpu/cpu.cpp
index 359c43db..1f0be6e3 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 1.96 2007-01-21 18:14:52 c2woody Exp $ */
+/* $Id: cpu.cpp,v 1.97 2007-02-04 11:10:22 qbix79 Exp $ */
 
 #include <assert.h>
 #include <sstream>
@@ -54,6 +54,7 @@ Bit32s CPU_CyclePercUsed = 100;
 Bit32s CPU_CycleLimit = -1;
 Bit32s CPU_CycleUp = 0;
 Bit32s CPU_CycleDown = 0;
+Bit64s CPU_IODelayRemoved = 0;
 CPU_Decoder * cpudecoder;
 bool CPU_CycleAutoAdjust;
 Bitu CPU_AutoDetermineMode;
diff --git a/src/dosbox.cpp b/src/dosbox.cpp
index c4ae9c41..8a3e7f0e 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 1.113 2007-01-21 18:14:40 c2woody Exp $ */
+/* $Id: dosbox.cpp,v 1.114 2007-02-04 11:10:22 qbix79 Exp $ */
 
 #include <stdlib.h>
 #include <stdarg.h>
@@ -162,19 +162,37 @@ increaseticks:
 				ticksRemain = 20;
 			}
 			ticksAdded = ticksRemain;
-			if (CPU_CycleAutoAdjust && (ticksAdded > 15 || ticksScheduled >= 250 || ticksDone >= 250) ) {
-				/* ratio we are aiming for is around 90% usage*/
-				Bits ratio = (ticksScheduled * (CPU_CyclePercUsed*90*1024/100/100)) / ticksDone;
-//				LOG_MSG("Done %d schedulded %d ratio %d cycles %d", ticksDone, ticksScheduled, ratio, CPU_CycleMax);
-				if (ratio <= 1024) 
-					CPU_CycleMax = (CPU_CycleMax * ratio) / 1024;
-				else 
-					CPU_CycleMax = 1 + (CPU_CycleMax >> 1) + (CPU_CycleMax * ratio) / 2048;
-				if (CPU_CycleLimit>0) {
-					if (CPU_CycleMax>CPU_CycleLimit) CPU_CycleMax=CPU_CycleLimit;
+			if (CPU_CycleAutoAdjust) {
+				if(ticksScheduled >= 250 || ticksDone >= 250 || (ticksAdded > 15 && ticksScheduled >= 5) ) {
+					/* ratio we are aiming for is around 90% usage*/
+					Bits ratio = (ticksScheduled * (CPU_CyclePercUsed*90*1024/100/100)) / ticksDone;
+					Bit32s new_cmax = CPU_CycleMax;
+					Bit64s cproc = (Bit64s)CPU_CycleMax * (Bit64s)ticksScheduled;
+					if(cproc > 0) {
+						double ratioremoved = (double) CPU_IODelayRemoved / (double) cproc;
+						if(ratioremoved < 1.0) {
+							ratio = (Bits)((double)ratio * (1 - ratioremoved));
+							if (ratio <= 1024) 
+								new_cmax = (CPU_CycleMax * ratio) / 1024;
+							else 
+								new_cmax = 1 + (CPU_CycleMax >> 1) + (CPU_CycleMax * ratio) / 2048;
+						}
+					}
+
+					// maybe care about not going negative
+					if (new_cmax > 0) 
+						CPU_CycleMax = new_cmax;
+					if (CPU_CycleLimit > 0) {
+						if (CPU_CycleMax>CPU_CycleLimit) CPU_CycleMax = CPU_CycleLimit;
+					}
+					CPU_IODelayRemoved = 0;
+					ticksDone = 0;
+					ticksScheduled = 0;
+				} else if (ticksAdded > 15) {
+					CPU_CycleMax /= 3;
+					if (CPU_CycleMax < 100)
+					CPU_CycleMax = 100;
 				}
-				ticksDone = 0;
-				ticksScheduled = 0;
 			}
 		} else {
 			ticksAdded = 0;
diff --git a/src/hardware/iohandler.cpp b/src/hardware/iohandler.cpp
index ce1ba9c2..5fc3f19a 100644
--- a/src/hardware/iohandler.cpp
+++ b/src/hardware/iohandler.cpp
@@ -16,7 +16,7 @@
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
-/* $Id: iohandler.cpp,v 1.24 2007-01-13 10:43:40 qbix79 Exp $ */
+/* $Id: iohandler.cpp,v 1.25 2007-02-04 11:10:22 qbix79 Exp $ */
 
 #include <string.h>
 #include "dosbox.h"
@@ -167,12 +167,11 @@ static Bits IOFaultCore(void) {
  * games with their timing of certain operations
  */
 
-extern Bit32s CPU_CycleMax;
 
 #define IODELAY_READ_MICROS 1.0
 #define IODELAY_WRITE_MICROS 0.75
 
-inline void IO_USEC_read_delay() {
+inline void IO_USEC_read_delay_old() {
 	if(CPU_CycleMax > static_cast<Bit32s>((IODELAY_READ_MICROS*1000.0))) {
 		// this could be calculated whenever CPU_CycleMax changes
 		Bitu delaycyc = static_cast<Bitu>((CPU_CycleMax/1000)*IODELAY_READ_MICROS);
@@ -181,7 +180,7 @@ inline void IO_USEC_read_delay() {
 	}
 }
 
-inline void IO_USEC_write_delay() {
+inline void IO_USEC_write_delay_old() {
 	if(CPU_CycleMax > static_cast<Bit32s>((IODELAY_WRITE_MICROS*1000.0))) {
 		// this could be calculated whenever CPU_CycleMax changes
 		Bitu delaycyc = static_cast<Bitu>((CPU_CycleMax/1000)*IODELAY_WRITE_MICROS); 
@@ -190,6 +189,27 @@ inline void IO_USEC_write_delay() {
 	}
 }
 
+
+#define IODELAY_READ_MICROSk (Bit32u)(1024/1.0)
+#define IODELAY_WRITE_MICROSk (Bit32u)(1024/0.75)
+
+inline void IO_USEC_read_delay() {
+	Bitu delaycyc = CPU_CycleMax/IODELAY_READ_MICROSk;
+	if(CPU_Cycles > delaycyc) {
+		CPU_Cycles -= delaycyc;
+		CPU_IODelayRemoved += delaycyc;
+	} else CPU_Cycles = 0;
+}
+
+inline void IO_USEC_write_delay() {
+	Bitu delaycyc = CPU_CycleMax/IODELAY_WRITE_MICROSk; 
+	if(CPU_Cycles > delaycyc) {
+		CPU_Cycles -= delaycyc;
+		CPU_IODelayRemoved += delaycyc;
+	} else CPU_Cycles = 0;
+}
+
+
 void IO_WriteB(Bitu port,Bitu val) {
 	if (GCC_UNLIKELY(GETFLAG(VM) && (CPU_IO_Exception(port,1)))) {
 		LazyFlags old_lflags;