Index: /trunk/src/VBox/VMM/VMMAll/IEMAllCImpl.cpp.h
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/IEMAllCImpl.cpp.h	(revision 38078)
+++ /trunk/src/VBox/VMM/VMMAll/IEMAllCImpl.cpp.h	(revision 38079)
@@ -2945,5 +2945,5 @@
     pCtx->ax = al;
     iemHlpUpdateArithEFlagsU8(pIemCpu, al,
-                              X86_EFL_SF | X86_EFL_SF | X86_EFL_PF,
+                              X86_EFL_SF | X86_EFL_ZF | X86_EFL_PF,
                               X86_EFL_OF | X86_EFL_AF | X86_EFL_CF);
 
@@ -2952,4 +2952,25 @@
 }
 
+
+/**
+ * Implements 'AAM'.
+ *
+ * @param   enmEffOpSize    The effective operand size.
+ */
+IEM_CIMPL_DEF_1(iemCImpl_aam, uint8_t, bImm)
+{
+    PCPUMCTX pCtx = pIemCpu->CTX_SUFF(pCtx);
+
+    uint16_t const ax = pCtx->ax;
+    uint8_t const  al = (uint8_t)ax % bImm;
+    uint8_t const  ah = (uint8_t)ax / bImm;
+    pCtx->ax = (ah << 8) + al;
+    iemHlpUpdateArithEFlagsU8(pIemCpu, al,
+                              X86_EFL_SF | X86_EFL_ZF | X86_EFL_PF,
+                              X86_EFL_OF | X86_EFL_AF | X86_EFL_CF);
+
+    iemRegAddToRip(pIemCpu, cbInstr);
+    return VINF_SUCCESS;
+}
 
 
Index: /trunk/src/VBox/VMM/VMMAll/IEMAllInstructions.cpp.h
===================================================================
--- /trunk/src/VBox/VMM/VMMAll/IEMAllInstructions.cpp.h	(revision 38078)
+++ /trunk/src/VBox/VMM/VMMAll/IEMAllInstructions.cpp.h	(revision 38079)
@@ -9833,5 +9833,12 @@
 
 /** Opcode 0xd4. */
-FNIEMOP_STUB(iemOp_aam_Ib);
+FNIEMOP_DEF(iemOp_aam_Ib)
+{
+    IEMOP_MNEMONIC("aam Ib");
+    uint8_t bImm; IEM_OPCODE_GET_NEXT_U8(&bImm);
+    IEMOP_HLP_NO_LOCK_PREFIX();
+    IEMOP_HLP_NO_64BIT();
+    return IEM_MC_DEFER_TO_CIMPL_1(iemCImpl_aam, bImm);
+}