diff --git a/sim/save.lua b/sim/save.lua
new file mode 100644
index 0000000..3765c79
--- /dev/null
+++ b/sim/save.lua
@@ -0,0 +1,12 @@
+
+logicsavecallbacks = {}
+
+function logicsavecallback(id, cb)
+	logicsavecallbacks[id] = cb
+end
+
+function logicsave()
+	for cbid, cb in pairs(logicsavecallbacks) do
+		cb()
+	end
+end