Index: /trunk/src/VBox/Devices/Storage/DevBusLogic.cpp
===================================================================
--- /trunk/src/VBox/Devices/Storage/DevBusLogic.cpp	(revision 40962)
+++ /trunk/src/VBox/Devices/Storage/DevBusLogic.cpp	(revision 40963)
@@ -1753,4 +1753,16 @@
             break;
         }
+
+        /* On BusLogic adapters, the interrupt and geometry registers are R/W.
+         * That is different from Adaptec 154x where those are read only.
+         */
+        case BUSLOGIC_REGISTER_INTERRUPT:
+            pBusLogic->regInterrupt = uVal;
+            break;
+
+        case BUSLOGIC_REGISTER_GEOMETRY:
+            pBusLogic->regGeometry = uVal;
+            break;
+
         default:
             AssertMsgFailed(("Register not available\n"));