diff --git a/src/cpu/core_full/op.h b/src/cpu/core_full/op.h
index bfcb90d1..6c1ebc4d 100644
--- a/src/cpu/core_full/op.h
+++ b/src/cpu/core_full/op.h
@@ -584,9 +584,13 @@ switch (inst.code.op) {
 		SETFLAGBIT(CF,(inst_op1_d & (1 << (inst_op2_d & 31))));
 		inst_op1_d&=~(1 << (inst_op2_d & 31));
 		break;
-	case O_BSWAP:
+	case O_BSWAPw:
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegalopcode;
-		BSWAP(inst_op1_d);
+		BSWAPW(inst_op1_w);
+		break;
+	case O_BSWAPd:
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegalopcode;
+		BSWAPD(inst_op1_d);
 		break;
 	case O_CMPXCHG:
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486NEWSLOW) goto illegalopcode;
diff --git a/src/cpu/core_full/optable.h b/src/cpu/core_full/optable.h
index 39907e0e..a938a8fe 100644
--- a/src/cpu/core_full/optable.h
+++ b/src/cpu/core_full/optable.h
@@ -321,10 +321,10 @@ static OpCode OpCodeTable[1024]={
 {0			,0			,0		,0		},{0		,0			,0		,0		},
 {0			,0			,0		,0		},{0		,0			,0		,0		},
 /* 0x1c8 - 0x1cf */
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_AX},{L_REGd	,O_BSWAP	,S_REGd	,REGI_CX},
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_DX},{L_REGd	,O_BSWAP	,S_REGd	,REGI_BX},
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_SP},{L_REGd	,O_BSWAP	,S_REGd	,REGI_BP},
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_SI},{L_REGd	,O_BSWAP	,S_REGd	,REGI_DI},
+{L_REGw		,O_BSWAPw	,S_REGw	,REGI_AX},{L_REGw	,O_BSWAPw	,S_REGw	,REGI_CX},
+{L_REGw		,O_BSWAPw	,S_REGw	,REGI_DX},{L_REGw	,O_BSWAPw	,S_REGw	,REGI_BX},
+{L_REGw		,O_BSWAPw	,S_REGw	,REGI_SP},{L_REGw	,O_BSWAPw	,S_REGw	,REGI_BP},
+{L_REGw		,O_BSWAPw	,S_REGw	,REGI_SI},{L_REGw	,O_BSWAPw	,S_REGw	,REGI_DI},
 
 /* 0x1d0 - 0x1d7 */
 {0			,0			,0		,0		},{0		,0			,0		,0		},
@@ -677,10 +677,10 @@ static OpCode OpCodeTable[1024]={
 {0			,0			,0		,0		},{0		,0			,0		,0		},
 {0			,0			,0		,0		},{0		,0			,0		,0		},
 /* 0x3c8 - 0x3cf */
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_AX},{L_REGd	,O_BSWAP	,S_REGd	,REGI_CX},
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_DX},{L_REGd	,O_BSWAP	,S_REGd	,REGI_BX},
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_SP},{L_REGd	,O_BSWAP	,S_REGd	,REGI_BP},
-{L_REGd		,O_BSWAP	,S_REGd	,REGI_SI},{L_REGd	,O_BSWAP	,S_REGd	,REGI_DI},
+{L_REGd		,O_BSWAPd	,S_REGd	,REGI_AX},{L_REGd	,O_BSWAPd	,S_REGd	,REGI_CX},
+{L_REGd		,O_BSWAPd	,S_REGd	,REGI_DX},{L_REGd	,O_BSWAPd	,S_REGd	,REGI_BX},
+{L_REGd		,O_BSWAPd	,S_REGd	,REGI_SP},{L_REGd	,O_BSWAPd	,S_REGd	,REGI_BP},
+{L_REGd		,O_BSWAPd	,S_REGd	,REGI_SI},{L_REGd	,O_BSWAPd	,S_REGd	,REGI_DI},
 
 /* 0x3d0 - 0x3d7 */
 {0			,0			,0		,0		},{0		,0			,0		,0		},
diff --git a/src/cpu/core_full/support.h b/src/cpu/core_full/support.h
index 59287409..7a0c4dc2 100644
--- a/src/cpu/core_full/support.h
+++ b/src/cpu/core_full/support.h
@@ -94,7 +94,8 @@ enum {
 	O_BTd,O_BTSd,O_BTRd,O_BTCd,
 	O_BSFw,O_BSRw,O_BSFd,O_BSRd,
 
-	O_BSWAP,O_CMPXCHG,
+	O_BSWAPw, O_BSWAPd,
+	O_CMPXCHG,
 	O_FPU
 
 
diff --git a/src/cpu/core_normal/prefix_0f.h b/src/cpu/core_normal/prefix_0f.h
index ff809886..b2340238 100644
--- a/src/cpu/core_normal/prefix_0f.h
+++ b/src/cpu/core_normal/prefix_0f.h
@@ -588,28 +588,28 @@
 			else {GetEAa;*rmrw=LoadMw(eaa);SaveMw(eaa,LoadMw(eaa)+oldrmrw);}
 			break;
 		}
-	CASE_0F_B(0xc8)												/* BSWAP EAX */
+	CASE_0F_W(0xc8)												/* BSWAP AX */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_eax);break;
-	CASE_0F_B(0xc9)												/* BSWAP ECX */
+		BSWAPW(reg_ax);break;
+	CASE_0F_W(0xc9)												/* BSWAP CX */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_ecx);break;
-	CASE_0F_B(0xca)												/* BSWAP EDX */
+		BSWAPW(reg_cx);break;
+	CASE_0F_W(0xca)												/* BSWAP DX */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_edx);break;
-	CASE_0F_B(0xcb)												/* BSWAP EBX */
+		BSWAPW(reg_dx);break;
+	CASE_0F_W(0xcb)												/* BSWAP BX */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_ebx);break;
-	CASE_0F_B(0xcc)												/* BSWAP ESP */
+		BSWAPW(reg_bx);break;
+	CASE_0F_W(0xcc)												/* BSWAP SP */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_esp);break;
-	CASE_0F_B(0xcd)												/* BSWAP EBP */
+		BSWAPW(reg_sp);break;
+	CASE_0F_W(0xcd)												/* BSWAP BP */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_ebp);break;
-	CASE_0F_B(0xce)												/* BSWAP ESI */
+		BSWAPW(reg_bp);break;
+	CASE_0F_W(0xce)												/* BSWAP SI */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_esi);break;
-	CASE_0F_B(0xcf)												/* BSWAP EDI */
+		BSWAPW(reg_si);break;
+	CASE_0F_W(0xcf)												/* BSWAP DI */
 		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
-		BSWAP(reg_edi);break;
+		BSWAPW(reg_di);break;
 		
diff --git a/src/cpu/core_normal/prefix_66_0f.h b/src/cpu/core_normal/prefix_66_0f.h
index 1563050b..b8aee894 100644
--- a/src/cpu/core_normal/prefix_66_0f.h
+++ b/src/cpu/core_normal/prefix_66_0f.h
@@ -439,3 +439,27 @@
 			else {GetEAa;*rmrd=LoadMd(eaa);SaveMd(eaa,LoadMd(eaa)+oldrmrd);}
 			break;
 		}
+	CASE_0F_D(0xc8)												/* BSWAP EAX */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_eax);break;
+	CASE_0F_D(0xc9)												/* BSWAP ECX */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_ecx);break;
+	CASE_0F_D(0xca)												/* BSWAP EDX */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_edx);break;
+	CASE_0F_D(0xcb)												/* BSWAP EBX */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_ebx);break;
+	CASE_0F_D(0xcc)												/* BSWAP ESP */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_esp);break;
+	CASE_0F_D(0xcd)												/* BSWAP EBP */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_ebp);break;
+	CASE_0F_D(0xce)												/* BSWAP ESI */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_esi);break;
+	CASE_0F_D(0xcf)												/* BSWAP EDI */
+		if (CPU_ArchitectureType<CPU_ARCHTYPE_486OLDSLOW) goto illegal_opcode;
+		BSWAPD(reg_edi);break;
diff --git a/src/cpu/instructions.h b/src/cpu/instructions.h
index e224d42a..cb1df6be 100644
--- a/src/cpu/instructions.h
+++ b/src/cpu/instructions.h
@@ -956,5 +956,8 @@
 	save(op1,lf_resd);											\
 	lflags.type=t_DSHRd;
 
-#define BSWAP(op1)														\
+#define BSWAPW(op1)														\
+	op1 = 0;
+
+#define BSWAPD(op1)														\
 	op1 = (op1>>24)|((op1>>8)&0xFF00)|((op1<<8)&0xFF0000)|((op1<<24)&0xFF000000);