diff --git a/include/interface/callbacks.hpp b/include/interface/callbacks.hpp
index 70a9964c..f1441850 100644
--- a/include/interface/callbacks.hpp
+++ b/include/interface/callbacks.hpp
@@ -2,6 +2,8 @@
 #define _interface__callbacks__hpp__included__
 
 #include <cstdint>
+#include <string>
+#include <list>
 #include "library/framebuffer.hpp"
 
 /**
@@ -21,6 +23,10 @@ public:
  * Returns the actual input value used.
  */
 	virtual int16_t set_input(unsigned port, unsigned index, unsigned control, int16_t value) = 0;
+/**
+ * Notifies about latch. Only called on some systems.
+ */
+	virtual void notify_latch(std::list<std::string>& l) = 0;
 /**
  * Tick the RTC timer.
  */
diff --git a/include/library/luabase.hpp b/include/library/luabase.hpp
index afc61c12..9977358d 100644
--- a/include/library/luabase.hpp
+++ b/include/library/luabase.hpp
@@ -86,6 +86,13 @@ public:
 		T val;
 		_store_tag(T& a, T v) : addr(a), val(v) {}
 	};
+	//Auxillary type for vararg-tag.
+	struct vararg_tag
+	{
+		std::list<std::string> args;
+		vararg_tag(std::list<std::string>& _args) : args(_args) {}
+		int pushargs(lua_state& L);
+	};
 
 	//Auxillary type for numeric-tag.
 	template<typename T> struct _numeric_tag
@@ -173,6 +180,12 @@ private:
 		tag.addr = NULL;
 	}
 
+	template<typename... T> void _callback(int argc, vararg_tag tag, T... args)
+	{
+		int e = tag.pushargs(*this);
+		_callback(argc + e, args...);
+	}
+
 	template<typename... T> void _callback(int argc, nil_tag tag, T... args)
 	{
 		pushnil();
diff --git a/include/lua/lua.hpp b/include/lua/lua.hpp
index a9443766..e0576cc8 100644
--- a/include/lua/lua.hpp
+++ b/include/lua/lua.hpp
@@ -32,6 +32,7 @@ void lua_callback_keyhook(const std::string& key, keyboard_key& p) throw();
 void lua_callback_do_unsafe_rewind(const std::vector<char>& save, uint64_t secs, uint64_t ssecs, movie& mov, void* u);
 bool lua_callback_do_button(uint32_t port, uint32_t controller, uint32_t index, const char* type);
 void lua_callback_movie_lost(const char* what);
+void lua_callback_do_latch(std::list<std::string>& args);
 
 #define LUA_TIMED_HOOK_IDLE 0
 #define LUA_TIMED_HOOK_TIMER 1
diff --git a/src/core/mainloop.cpp b/src/core/mainloop.cpp
index c6b74abd..74f7cf40 100644
--- a/src/core/mainloop.cpp
+++ b/src/core/mainloop.cpp
@@ -419,6 +419,7 @@ uint64_t audio_irq_time;
 uint64_t controller_irq_time;
 uint64_t frame_irq_time;
 
+
 struct lsnes_callbacks : public emucore_callbacks
 {
 public:
@@ -444,6 +445,11 @@ public:
 		return movb.get_movie().next_input(port, index, control);
 	}
 
+	void notify_latch(std::list<std::string>& args)
+	{
+		lua_callback_do_latch(args);
+	}
+
 	void timer_tick(uint32_t increment, uint32_t per_second)
 	{
 		our_movie.rtc_subsecond += increment;
@@ -493,6 +499,17 @@ public:
 
 namespace
 {
+	function_ptr_command<const std::string&> test4(lsnes_cmd, "test4", "test", "test", 
+		[](const std::string& args) throw(std::bad_alloc, std::runtime_error) {
+			std::list<std::string> _args;
+			std::string args2 = args;
+			while(args2 != "") {
+				std::string sym;
+				extract_token(args2, sym, " \t");
+				_args.push_back(sym);
+			}
+			lua_callback_do_latch(_args);
+		});
 	function_ptr_command<> count_rerecords(lsnes_cmd, "count-rerecords", "Count rerecords",
 		"Syntax: count-rerecords\nCounts rerecords.\n",
 		[]() throw(std::bad_alloc, std::runtime_error) {
diff --git a/src/emulation/bsnes-legacy/core.cpp b/src/emulation/bsnes-legacy/core.cpp
index d5bb5eec..61bf3def 100644
--- a/src/emulation/bsnes-legacy/core.cpp
+++ b/src/emulation/bsnes-legacy/core.cpp
@@ -348,6 +348,12 @@ namespace
 			return ecore_callbacks->get_randomseed();
 		}
 
+		void notifyLatched()
+		{
+			std::list<std::string> dummy;
+			ecore_callbacks->notify_latch(dummy);
+		}
+
 		void videoRefresh(const uint32_t* data, bool hires, bool interlace, bool overscan);
 
 		void audioSample(int16_t l_sample, int16_t r_sample)
diff --git a/src/library/luabase.cpp b/src/library/luabase.cpp
index f8ddcba3..51bb770d 100644
--- a/src/library/luabase.cpp
+++ b/src/library/luabase.cpp
@@ -340,3 +340,24 @@ std::string try_print_userdata(lua_state& L, int index)
 			return i.print(L, index);
 	return "no data available";
 }
+
+int lua_state::vararg_tag::pushargs(lua_state& L)
+{
+	int e = 0;
+	for(auto i : args) {
+		if(i == "")
+			L.pushnil();
+		else if(i == "true")
+			L.pushboolean(true);
+		else if(i == "false")
+			L.pushboolean(false);
+		else if(regex_match("[+-]?(|0|[1-9][0-9]*)(.[0-9]+)?([eE][+-]?(0|[1-9][0-9]*))?", i))
+			L.pushnumber(strtod(i.c_str(), NULL));
+		else if(i[0] == ':')
+			L.pushlstring(i.substr(1));
+		else
+			L.pushlstring(i);
+		e++;
+	}
+	return e;
+}
diff --git a/src/lua/lua.cpp b/src/lua/lua.cpp
index 099740a9..b6fd88da 100644
--- a/src/lua/lua.cpp
+++ b/src/lua/lua.cpp
@@ -271,6 +271,7 @@ namespace
 	DEFINE_CB(pre_rewind);
 	DEFINE_CB(post_rewind);
 	DEFINE_CB(set_rewind);
+	DEFINE_CB(latch);
 }
 
 void lua_callback_do_paint(struct lua_render_context* ctx, bool non_synthetic) throw()
@@ -503,6 +504,11 @@ void lua_callback_movie_lost(const char* what)
 	run_callback(on_movie_lost, std::string(what));
 }
 
+void lua_callback_do_latch(std::list<std::string>& args)
+{
+	run_callback(on_latch, lua_state::vararg_tag(args));
+}
+
 bool lua_requests_repaint = false;
 bool lua_requests_subframe_paint = false;