diff --git a/zsnes/src/cpu/65816d.inc b/zsnes/src/cpu/65816d.inc
index 828ec325..fe9c0948 100644
--- a/zsnes/src/cpu/65816d.inc
+++ b/zsnes/src/cpu/65816d.inc
@@ -393,6 +393,7 @@ NEWSYM joinflags
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpb]
     mov [eax+ebx],cl
@@ -448,6 +449,7 @@ BRKemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpc+1]
     mov [eax+ebx],cl
@@ -537,6 +539,7 @@ BRKemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpb]
     mov [eax+ebx],cl
@@ -592,6 +595,7 @@ COPemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpc+1]
     mov [eax+ebx],cl
diff --git a/zsnes/src/cpu/65816db.inc b/zsnes/src/cpu/65816db.inc
index 43188113..1e07a166 100644
--- a/zsnes/src/cpu/65816db.inc
+++ b/zsnes/src/cpu/65816db.inc
@@ -382,6 +382,7 @@ EXTSYM dmadata
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpb]
     mov [eax+ebx],cl
@@ -437,6 +438,7 @@ BRKemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpc+1]
     mov [eax+ebx],cl
@@ -535,6 +537,7 @@ BRKemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpb]
     mov [eax+ebx],cl
@@ -590,6 +593,7 @@ COPemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpc+1]
     mov [eax+ebx],cl
diff --git a/zsnes/src/cpu/65816dc.inc b/zsnes/src/cpu/65816dc.inc
index 19ace61f..8c9a5a37 100644
--- a/zsnes/src/cpu/65816dc.inc
+++ b/zsnes/src/cpu/65816dc.inc
@@ -392,6 +392,7 @@ EXTSYM dmadata
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpb]
     mov [eax+ebx],cl
@@ -447,6 +448,7 @@ BRKemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpc+1]
     mov [eax+ebx],cl
@@ -545,6 +547,7 @@ BRKemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpb]
     mov [eax+ebx],cl
@@ -600,6 +603,7 @@ COPemulmode
     sub ebx,eax
     mov [xpc],bx
     mov eax,[wramdata]
+    xor ebx,ebx
     mov bx,[xs]
     mov cl,[xpc+1]
     mov [eax+ebx],cl
diff --git a/zsnes/src/cpu/e65816.inc b/zsnes/src/cpu/e65816.inc
index b0c84a33..a2ac741c 100644
--- a/zsnes/src/cpu/e65816.inc
+++ b/zsnes/src/cpu/e65816.inc
@@ -1903,8 +1903,13 @@ COp5B:   ; TCD i
     endloop
 COp1B:   ; TCS i
     mov ax,[xa]
+    test byte[xe],1
+    jnz .emul
     mov [xs],ax
     endloop
+.emul
+    mov [xs],al
+    endloop
 COp7B:   ; TDC i
     mov ax,[xd]
     mov [xa],ax
diff --git a/zsnes/src/cpu/e65816b.inc b/zsnes/src/cpu/e65816b.inc
index 6f95f2ca..ba09a70c 100644
--- a/zsnes/src/cpu/e65816b.inc
+++ b/zsnes/src/cpu/e65816b.inc
@@ -1896,8 +1896,13 @@ COp5B:   ; TCD i
     endloop
 COp1B:   ; TCS i
     mov ax,[xa]
+    test byte[xe],1
+    jnz .emul
     mov [xs],ax
     endloop
+.emul
+    mov [xs],al
+    endloop
 COp7B:   ; TDC i
     mov ax,[xd]
     mov [xa],ax
diff --git a/zsnes/src/cpu/e65816c.inc b/zsnes/src/cpu/e65816c.inc
index 744f9ea2..a266f18e 100644
--- a/zsnes/src/cpu/e65816c.inc
+++ b/zsnes/src/cpu/e65816c.inc
@@ -1896,8 +1896,13 @@ COp5B:   ; TCD i
     endloop
 COp1B:   ; TCS i
     mov ax,[xa]
+    test byte[xe],1
+    jnz .emul
     mov [xs],ax
     endloop
+.emul
+    mov [xs],al
+    endloop
 COp7B:   ; TDC i
     mov ax,[xd]
     mov [xa],ax
diff --git a/zsnes/src/cpu/irq.asm b/zsnes/src/cpu/irq.asm
index 3344e15a..6010cf76 100644
--- a/zsnes/src/cpu/irq.asm
+++ b/zsnes/src/cpu/irq.asm
@@ -152,6 +152,7 @@ NEWSYM NMIemulmode
     mov [xs],cx
 
     xor bh,bh
+    mov [xpb],bh
     mov bl,[xpb]
     xor eax,eax
     mov ax,[nmiv8]
@@ -320,6 +321,7 @@ NEWSYM IRQemulmode
     mov [xs],cx
 
     xor bh,bh
+    mov [xpb],bh
     mov bl,[xpb]
     xor eax,eax
     mov ax,[irqv8]
@@ -428,6 +430,7 @@ NEWSYM IRQemulmodedeb
     mov [xs],cx
 
     xor bh,bh
+    mov [xpb],bh
     mov bl,[xpb]
     xor eax,eax
     mov ax,[irqv8]
@@ -534,6 +537,7 @@ NEWSYM NMIemulmodedeb
     mov [xs],cx
 
     xor bh,bh
+    mov [xpb],bh
     mov bl,[xpb]
     xor eax,eax
     mov ax,[nmiv8]