diff -ruN v46e2\driver\bsmaster.h v46e3\driver\bsmaster.h
--- v46e2\driver\bsmaster.h	Sun May 22 17:15:42 2016
+++ v46e3\driver\bsmaster.h	Fri Apr 07 15:16:00 2017
@@ -1896,8 +1896,9 @@
 #define VM_VMWARE    0x03
 #define VM_QEMU      0x04
 #define VM_BOCHS     0x05
+#define VM_PCEM      0x06
 
-#define VM_MAX_KNOWN VM_BOCHS
+#define VM_MAX_KNOWN VM_PCEM
 
 extern BOOLEAN WinVer_WDM_Model;
 
diff -ruN v46e2\driver\id_ata.cpp v46e3\driver\id_ata.cpp
--- v46e2\driver\id_ata.cpp	Sun May 22 17:32:56 2016
+++ v46e3\driver\id_ata.cpp	Fri Apr 07 15:33:06 2017
@@ -1917,6 +1917,8 @@
         // Check for HDDs > 8Gb
         if ((deviceExtension->FullIdentifyData.NumberOfCylinders == 0x3fff) &&
 /*            (deviceExtension->FullIdentifyData.TranslationFieldsValid) &&*/
+             deviceExtension->FullIdentifyData.NumberOfHeads &&
+             deviceExtension->FullIdentifyData.SectorsPerTrack &&
             (NumOfSectors < deviceExtension->FullIdentifyData.UserAddressableSectors)) {
             KdPrint2((PRINT_PREFIX "NumberOfCylinders == 0x3fff\n"));
             cylinders = 
@@ -1960,6 +1962,8 @@
         if(LunExt->DeviceFlags & DFLAGS_LBA_ENABLED) {
             if(deviceExtension->FullIdentifyData.FeaturesSupport.Address48 &&
                deviceExtension->FullIdentifyData.FeaturesEnabled.Address48 &&
+               deviceExtension->FullIdentifyData.NumberOfHeads &&
+               deviceExtension->FullIdentifyData.SectorsPerTrack &&
                (deviceExtension->FullIdentifyData.UserAddressableSectors48 > NumOfSectors)
                ) {
                 KdPrint2((PRINT_PREFIX "LBA48\n"));
@@ -2093,8 +2097,21 @@
 
         // fill IdentifyData with bogus geometry
         KdPrint2((PRINT_PREFIX "requested LunExt->GeomType=%x\n", LunExt->opt_GeomType));
-        tmp_cylinders = NumOfSectors / (deviceExtension->FullIdentifyData.CurrentSectorsPerTrack *
-                                        deviceExtension->FullIdentifyData.NumberOfCurrentHeads);
+        if(deviceExtension->FullIdentifyData.CurrentSectorsPerTrack &&
+           deviceExtension->FullIdentifyData.NumberOfCurrentHeads) {
+          tmp_cylinders = NumOfSectors / (deviceExtension->FullIdentifyData.CurrentSectorsPerTrack *
+                                          deviceExtension->FullIdentifyData.NumberOfCurrentHeads);
+        } else
+        if(deviceExtension->FullIdentifyData.SectorsPerTrack &&
+           deviceExtension->FullIdentifyData.NumberOfHeads) {
+            KdPrint2((PRINT_PREFIX "Current C/H = %#I64x/%#I64x\n",
+                deviceExtension->FullIdentifyData.CurrentSectorsPerTrack,
+                deviceExtension->FullIdentifyData.NumberOfCurrentHeads));
+            tmp_cylinders = NumOfSectors / (deviceExtension->FullIdentifyData.SectorsPerTrack *
+                                            deviceExtension->FullIdentifyData.NumberOfHeads);
+        } else {
+            tmp_cylinders = 0;
+        }
         KdPrint2((PRINT_PREFIX "tmp_cylinders = %#I64x\n", tmp_cylinders));
         if((tmp_cylinders < 0xffff) || (LunExt->opt_GeomType == GEOM_ORIG)) {
             // ok, we can keep original values
@@ -2116,6 +2133,11 @@
             }
         }
 
+        if(!deviceExtension->FullIdentifyData.SectorsPerTrack ||
+           !deviceExtension->FullIdentifyData.NumberOfHeads) {
+            KdPrint2((PRINT_PREFIX "Zero S/H -> Force Use GEOM_STD\n"));
+        }
+
         if(LunExt->opt_GeomType == GEOM_STD) {
             deviceExtension->FullIdentifyData.CurrentSectorsPerTrack =
             deviceExtension->FullIdentifyData.SectorsPerTrack = 63;
@@ -5845,6 +5867,10 @@
 
             statusByte = WaitOnBusy(chan);
 
+            if(wordCount&1 && atapiDev && (g_opt_VirtualMachine == VM_BOCHS)) {
+                KdPrint2((PRINT_PREFIX 
+                          "IdeIntr: unaligned ATAPI %#x Words\n", wordCount));
+            } else
             if(LunExt->DeviceFlags & DFLAGS_DWORDIO_ENABLED) {
                 KdPrint2((PRINT_PREFIX 
                           "IdeIntr: pre-Read %#x Dwords\n", wordCount/2));