Samurai Shodown special hack (problem with irq)

zsnes/src/init.asm

@@ -1465,6 +1465,19 @@ NEWSYM headerhack
     mov byte[ENVDisable],0
     mov byte[MMXSRAMFix],0
 
+    mov esi,[romdata]
+    add esi,0FFC0h
+    cmp dword[esi],'SAMU'
+    jne .notsamuraishodown
+    cmp dword[esi+4],'RAI '
+    jne .notsamuraishodown
+    cmp dword[esi+8],'SHOD'
+    jne .notsamuraishodown
+    cmp dword[esi+12],'OWN '
+    jne .notsamuraishodown
+    mov word [IRQHack],1
+.notsamuraishodown
+
     mov esi,[romdata]
     add esi,07FC0h
     cmp dword[esi],0DFCAB0BDh