diff --git a/zsnes/src/cpu/e65816.inc b/zsnes/src/cpu/e65816.inc
index b81cacc8..2f3b0303 100644
--- a/zsnes/src/cpu/e65816.inc
+++ b/zsnes/src/cpu/e65816.inc
@@ -494,23 +494,7 @@ COpCDm16:; CMP a
    CMPMacro16b
 COpCFm8: ; CMP al
    addr_al_8br
-   mov bl,[esi-1]
-   mov cx,[esi-3]
-   test ecx,8000h
-   jz .loweraddr2
-   add ecx,[snesmmap+ebx*4]
-   jmp .nextaddr
-.loweraddr2
-   add ecx,[snesmap2+ebx*4]
-.nextaddr
-   cmp ecx,esi
-   je .ne
-.equal
-   xor ecx,ecx
    CMPMacro8b
-.ne
-   xor al,al
-   jmp .equal
 COpCFm16:; CMP al
    addr_al_16br
    CMPMacro16b
diff --git a/zsnes/src/init.asm b/zsnes/src/init.asm
index 2dfc075f..daf82c01 100644
--- a/zsnes/src/init.asm
+++ b/zsnes/src/init.asm
@@ -2026,6 +2026,29 @@ NEWSYM initsnes
     mov dword[NoiseDisTemp],0
     mov dword[NoiseDisTemp+4],0
 
+    mov esi,[romdata]
+    add esi,7FC0h
+    cmp dword[esi],'MEGA'
+    jne .notmmx
+    cmp dword[esi+4],'MAN '
+    jne .notmmx
+    cmp dword[esi+8],'X   '
+    jne .notmmx
+    mov esi,[romdata]
+    cmp byte[esi+824Ah],0F0h
+    jne .mmxa
+    mov byte[esi+824Ah],080h
+.mmxa
+    cmp byte[esi+21FC3h],0F0h
+    jne .mmxb
+    mov byte[esi+21FC3h],080h
+.mmxb
+    cmp byte[esi+2241Bh],0F0h
+    jne .mmxc
+    mov byte[esi+2241Bh],080h
+.mmxc
+.notmmx
+
     mov esi,[romdata]
     add esi,7FC0h
     cmp word[esi],'BS'  ; 7FFFFFA