diff --git a/src/devices/machine/netlist.cpp b/src/devices/machine/netlist.cpp
index ce13f33dcfe..4d829bdc4d8 100644
--- a/src/devices/machine/netlist.cpp
+++ b/src/devices/machine/netlist.cpp
@@ -1363,7 +1363,8 @@ void netlist_mame_cpu_device::device_start()
 
 void netlist_mame_cpu_device::nl_register_devices(netlist::nlparse_t &parser) const
 {
-	parser.factory().add<nld_analog_callback>( "NETDEV_CALLBACK", "-", std::move(PSOURCELOC()));
+	parser.factory().add<nld_analog_callback>( "NETDEV_CALLBACK",
+		netlist::factory::properties("-", std::move(PSOURCELOC())));
 }
 
 uint64_t netlist_mame_cpu_device::execute_clocks_to_cycles(uint64_t clocks) const noexcept
@@ -1522,8 +1523,10 @@ void netlist_mame_sound_device::device_start()
 
 void netlist_mame_sound_device::nl_register_devices(netlist::nlparse_t &parser) const
 {
-	parser.factory().add<nld_sound_out>("NETDEV_SOUND_OUT", "+CHAN", std::move(PSOURCELOC()));
-	parser.factory().add<nld_sound_in>("NETDEV_SOUND_IN", "-", std::move(PSOURCELOC()));
+	parser.factory().add<nld_sound_out>("NETDEV_SOUND_OUT",
+		netlist::factory::properties("+CHAN", std::move(PSOURCELOC())));
+	parser.factory().add<nld_sound_in>("NETDEV_SOUND_IN",
+		netlist::factory::properties("-", std::move(PSOURCELOC())));
 }
 
 void netlist_mame_sound_device::device_clock_changed()
diff --git a/src/lib/netlist/devices/nlid_truthtable.cpp b/src/lib/netlist/devices/nlid_truthtable.cpp
index 59cb3e819a7..07b490dc3c3 100644
--- a/src/lib/netlist/devices/nlid_truthtable.cpp
+++ b/src/lib/netlist/devices/nlid_truthtable.cpp
@@ -241,8 +241,8 @@ namespace devices
 	{
 	public:
 		netlist_factory_truthtable_t(const pstring &name,
-			const pstring &def_param, plib::source_location &&sourceloc)
-		: truthtable_base_element_t(name, def_param, std::move(sourceloc))
+			factory::properties &&props)
+		: truthtable_base_element_t(name, std::move(props))
 		{ }
 
 		unique_pool_ptr<core_device_t> make_device(nlmempool &pool, netlist_state_t &anetlist, const pstring &name) override
@@ -472,8 +472,8 @@ namespace factory
 {
 
 	truthtable_base_element_t::truthtable_base_element_t(const pstring &name,
-			const pstring &def_param, plib::source_location &&sourceloc)
-	: factory::element_t(name, def_param, std::move(sourceloc))
+		properties &&props)
+	: factory::element_t(name, std::move(props))
 	, m_family_name(NETLIST_DEFAULT_LOGIC_FAMILY)
 	{
 	}
@@ -481,31 +481,31 @@ namespace factory
 	#define ENTRYY(n, m, s)    case (n * 100 + m): \
 		{ using xtype = devices::netlist_factory_truthtable_t<n, m>; \
 			auto cs=s; \
-			ret = plib::make_unique<xtype>(desc.name, desc.def_param, std::move(cs)); } \
+			ret = plib::make_unique<xtype>(desc.name, std::move(cs)); } \
 			break
 
 	#define ENTRY(n, s) ENTRYY(n, 1, s); ENTRYY(n, 2, s); ENTRYY(n, 3, s); \
 						ENTRYY(n, 4, s); ENTRYY(n, 5, s); ENTRYY(n, 6, s); \
 						ENTRYY(n, 7, s); ENTRYY(n, 8, s)
 
-	plib::unique_ptr<truthtable_base_element_t> truthtable_create(tt_desc &desc, plib::source_location &&sourceloc)
+	plib::unique_ptr<truthtable_base_element_t> truthtable_create(tt_desc &desc, properties &&props)
 	{
 		plib::unique_ptr<truthtable_base_element_t> ret;
 
 		switch (desc.ni * 100 + desc.no)
 		{
-			ENTRY(1, sourceloc);
-			ENTRY(2, sourceloc);
-			ENTRY(3, sourceloc);
-			ENTRY(4, sourceloc);
-			ENTRY(5, sourceloc);
-			ENTRY(6, sourceloc);
-			ENTRY(7, sourceloc);
-			ENTRY(8, sourceloc);
-			ENTRY(9, sourceloc);
-			ENTRY(10, sourceloc);
-			ENTRY(11, sourceloc);
-			ENTRY(12, sourceloc);
+			ENTRY(1, props);
+			ENTRY(2, props);
+			ENTRY(3, props);
+			ENTRY(4, props);
+			ENTRY(5, props);
+			ENTRY(6, props);
+			ENTRY(7, props);
+			ENTRY(8, props);
+			ENTRY(9, props);
+			ENTRY(10, props);
+			ENTRY(11, props);
+			ENTRY(12, props);
 			default:
 				pstring msg = plib::pfmt("unable to create truthtable<{1},{2}>")(desc.ni)(desc.no);
 				nl_assert_always(false, msg.c_str());
diff --git a/src/lib/netlist/devices/nlid_truthtable.h b/src/lib/netlist/devices/nlid_truthtable.h
index 0af5248c3ee..820ae091f70 100644
--- a/src/lib/netlist/devices/nlid_truthtable.h
+++ b/src/lib/netlist/devices/nlid_truthtable.h
@@ -200,15 +200,14 @@ namespace factory
 	class truthtable_base_element_t : public factory::element_t
 	{
 	public:
-		truthtable_base_element_t(const pstring &name,
-			const pstring &def_param, plib::source_location &&sourceloc);
+		truthtable_base_element_t(const pstring &name,properties &&props);
 
 		std::vector<pstring> m_desc;
 		pstring m_family_name;
 	};
 
 	plib::unique_ptr<truthtable_base_element_t> truthtable_create(tt_desc &desc,
-		plib::source_location &&sourceloc);
+		properties &&props);
 
 } // namespace factory
 } // namespace netlist
diff --git a/src/lib/netlist/nl_factory.cpp b/src/lib/netlist/nl_factory.cpp
index be641f2ae42..75f592b0853 100644
--- a/src/lib/netlist/nl_factory.cpp
+++ b/src/lib/netlist/nl_factory.cpp
@@ -27,16 +27,9 @@ namespace factory {
 		NETLIB_UPDATEI() { }
 	};
 
-	element_t::element_t(const pstring &name, const pstring &def_param,
-		plib::source_location &&sourceloc)
-		: m_name(name), m_def_param(def_param),
-		  m_sourceloc(sourceloc)
-	{
-	}
-
-	element_t::element_t(const pstring &name, const pstring &def_param)
-		: m_name(name), m_def_param(def_param),
-		  m_sourceloc("<unknown>", 1)
+	element_t::element_t(const pstring &name, properties &&props)
+	: m_name(name)
+	, m_properties(props)
 	{
 	}
 
diff --git a/src/lib/netlist/nl_factory.h b/src/lib/netlist/nl_factory.h
index 66cce44e8d0..f39cd5fce0f 100644
--- a/src/lib/netlist/nl_factory.h
+++ b/src/lib/netlist/nl_factory.h
@@ -29,8 +29,8 @@
 			() \
 	{ \
 		using devtype = factory::device_element_t<ns :: NETLIB_NAME(chip)>; \
-		auto sl(PSOURCELOC()); \
-		return devtype::create(p_name, p_def_param, std::move(sl)); \
+		auto sl(factory::properties(p_def_param, PSOURCELOC())); \
+		return devtype::create(p_name, std::move(sl)); \
 	} \
 	\
 	factory::constructor_ptr_t decl_ ## p_alias = NETLIB_NAME(p_alias ## _c);
@@ -42,6 +42,30 @@ namespace netlist {
 	class netlist_state_t;
 
 namespace factory {
+
+	struct properties
+	{
+		properties(const pstring &defparam, plib::source_location &&sourceloc)
+		: m_defparam(defparam)
+		, m_sourceloc(std::move(sourceloc))
+		{ }
+
+		PCOPYASSIGNMOVE(properties, default)
+
+		const pstring &defparam() const noexcept
+		{
+			return m_defparam;
+		}
+
+		const plib::source_location &source() const noexcept
+		{
+			return m_sourceloc;
+		}
+	private:
+		pstring m_defparam;
+		plib::source_location m_sourceloc;
+	};
+
 	// -----------------------------------------------------------------------------
 	// net_dev class factory
 	// -----------------------------------------------------------------------------
@@ -49,9 +73,7 @@ namespace factory {
 	class element_t
 	{
 	public:
-		element_t(const pstring &name, const pstring &def_param);
-		element_t(const pstring &name, const pstring &def_param,
-			plib::source_location &&sourceloc);
+		element_t(const pstring &name, properties &&props);
 		virtual ~element_t() = default;
 
 		PCOPYASSIGNMOVE(element_t, default)
@@ -67,13 +89,12 @@ namespace factory {
 		}
 
 		const pstring &name() const noexcept { return m_name; }
-		const pstring &param_desc() const noexcept { return m_def_param; }
-		const plib::source_location &source() const noexcept { return m_sourceloc; }
+		const pstring &param_desc() const noexcept { return m_properties.defparam(); }
+		const plib::source_location &source() const noexcept { return m_properties.source(); }
 
 	private:
 		pstring m_name;                             ///< device name
-		pstring m_def_param;                        ///< default parameter
-		plib::source_location m_sourceloc;          ///< source file
+		properties m_properties;                    ///< source file and other information and settings
 	};
 
 	template <class C>
@@ -84,11 +105,8 @@ namespace factory {
 		using device_ptr = unique_pool_ptr<core_device_t>;
 		using element_ptr = plib::unique_ptr<device_element_t<C>>;
 
-		device_element_t(const pstring &name, const pstring &def_param)
-		: element_t(name, def_param) { }
-		device_element_t(const pstring &name, const pstring &def_param,
-			plib::source_location &&sourceloc)
-		: element_t(name, def_param, std::move(sourceloc)) { }
+		device_element_t(const pstring &name, properties &&props)
+		: element_t(name, std::move(props)) { }
 
 		device_ptr make_device(nlmempool &pool,
 			netlist_state_t &anetlist,
@@ -97,10 +115,9 @@ namespace factory {
 			return pool.make_unique<C>(anetlist, name);
 		}
 
-		static element_ptr create(const pstring &name,
-			const pstring &def_param, plib::source_location &&sourceloc)
+		static element_ptr create(const pstring &name, properties &&props)
 		{
-			return plib::make_unique<device_element_t<C>>(name, def_param, std::move(sourceloc));
+			return plib::make_unique<device_element_t<C>>(name, std::move(props));
 		}
 	};
 
@@ -113,10 +130,9 @@ namespace factory {
 		PCOPYASSIGNMOVE(list_t, delete)
 
 		template<class device_class>
-		void add(const pstring &name, const pstring &def_param,
-			plib::source_location &&sourceloc)
+		void add(const pstring &name, properties &&props)
 		{
-			add(device_element_t<device_class>::create(name, def_param, std::move(sourceloc)));
+			add(device_element_t<device_class>::create(name, std::move(props)));
 		}
 
 		void add(plib::unique_ptr<element_t> &&factory) noexcept(false);
@@ -140,9 +156,9 @@ namespace factory {
 	using constructor_ptr_t = plib::unique_ptr<element_t> (*)();
 
 	template <typename T>
-	plib::unique_ptr<element_t> constructor_t(const pstring &name, const pstring &def_param)
+	plib::unique_ptr<element_t> constructor_t(const pstring &name, properties &&props)
 	{
-		return plib::make_unique<device_element_t<T>>(name, def_param);
+		return plib::make_unique<device_element_t<T>>(name, std::move(props));
 	}
 
 	// -----------------------------------------------------------------------------
@@ -153,9 +169,8 @@ namespace factory {
 	{
 	public:
 
-		library_element_t(const pstring &name, const pstring &def_param,
-			plib::source_location &&sourceloc)
-		: element_t(name, def_param, std::move(sourceloc))
+		library_element_t(const pstring &name, properties &&props)
+		: element_t(name, std::move(props))
 		{
 		}
 
diff --git a/src/lib/netlist/nl_parser.cpp b/src/lib/netlist/nl_parser.cpp
index 84b09bde1e0..8e76538632a 100644
--- a/src/lib/netlist/nl_parser.cpp
+++ b/src/lib/netlist/nl_parser.cpp
@@ -133,7 +133,7 @@ void parser_t::parse_netlist(const pstring &nlname)
 		{
 			require_token(m_tok_paren_left);
 			// FIXME: Need to pass in parameter definition FIXME: get line number right
-			m_setup.register_lib_entry(get_identifier(), "", plib::source_location("parser: " + nlname, 1));
+			m_setup.register_lib_entry(get_identifier(), factory::properties("", plib::source_location("parser: " + nlname, 1)));
 			require_token(m_tok_paren_right);
 		}
 		else if (token.is(m_tok_NETLIST_END))
@@ -166,7 +166,6 @@ void parser_t::net_truthtable_start(const pstring &nlname)
 	desc.name = name;
 	desc.ni = static_cast<unsigned long>(ni);
 	desc.no = static_cast<unsigned long>(no);
-	desc.def_param = "+" + def_param;
 	desc.family = "";
 
 	while (true)
@@ -200,7 +199,7 @@ void parser_t::net_truthtable_start(const pstring &nlname)
 			require_token(m_tok_paren_left);
 			require_token(m_tok_paren_right);
 			// FIXME: proper location
-			m_setup.truthtable_create(desc, plib::source_location(nlname, 1));
+			m_setup.truthtable_create(desc, factory::properties("+" + def_param, plib::source_location(nlname, 1)));
 			return;
 		}
 	}
diff --git a/src/lib/netlist/nl_setup.cpp b/src/lib/netlist/nl_setup.cpp
index b6df8b562e5..2c89542c52d 100755
--- a/src/lib/netlist/nl_setup.cpp
+++ b/src/lib/netlist/nl_setup.cpp
@@ -170,7 +170,6 @@ namespace netlist
 		throw nl_exception(MF_NOT_FOUND_IN_SOURCE_COLLECTION(netlist_name));
 	}
 
-
 	void nlparse_t::namespace_push(const pstring &aname)
 	{
 		if (m_namespace_stack.empty())
@@ -234,10 +233,9 @@ namespace netlist
 		m_abstract.m_defparams.emplace_back(namespace_prefix() + name, def);
 	}
 
-	void nlparse_t::register_lib_entry(const pstring &name, const
-		pstring &paramdef, plib::source_location &&sourceloc)
+	void nlparse_t::register_lib_entry(const pstring &name, factory::properties &&props)
 	{
-		m_factory.add(plib::make_unique<factory::library_element_t>(name, paramdef, std::move(sourceloc)));
+		m_factory.add(plib::make_unique<factory::library_element_t>(name, std::move(props)));
 	}
 
 	void nlparse_t::register_frontier(const pstring &attach, const pstring &r_IN,
@@ -273,9 +271,9 @@ namespace netlist
 		register_link(attach, frontier_name + ".Q");
 	}
 
-	void nlparse_t::truthtable_create(tt_desc &desc, plib::source_location &&sourceloc)
+	void nlparse_t::truthtable_create(tt_desc &desc, factory::properties &&props)
 	{
-		auto fac = factory::truthtable_create(desc, std::move(sourceloc));
+		auto fac = factory::truthtable_create(desc, std::move(props));
 		m_factory.add(std::move(fac));
 	}
 
diff --git a/src/lib/netlist/nl_setup.h b/src/lib/netlist/nl_setup.h
index ebd602d04de..4833c6cb73e 100644
--- a/src/lib/netlist/nl_setup.h
+++ b/src/lib/netlist/nl_setup.h
@@ -84,11 +84,13 @@ void NETLIST_NAME(name)(netlist::nlparse_t &setup)                             \
 // FIXME: Need to pass in parameter definition
 #define LOCAL_LIB_ENTRY_1(name)                                                \
 		LOCAL_SOURCE(name)                                                     \
-		setup.register_lib_entry(# name, "", PSOURCELOC());
+		setup.register_lib_entry(# name,                                       \
+			netlist::factory::properties("", PSOURCELOC()));
 
 #define LOCAL_LIB_ENTRY_2(name, param_spec)                                    \
 		LOCAL_SOURCE(name)                                                     \
-		setup.register_lib_entry(# name, param_spec, PSOURCELOC());
+		setup.register_lib_entry(# name,                                       \
+			netlist::factory::properties(param_spec, PSOURCELOC()));
 
 #define LOCAL_LIB_ENTRY(...) PCALLVARARG(LOCAL_LIB_ENTRY_, __VA_ARGS__)
 
@@ -107,14 +109,14 @@ void NETLIST_NAME(name)(netlist::nlparse_t &setup)                             \
 // truthtable defines
 // -----------------------------------------------------------------------------
 
-#define TRUTHTABLE_START(cname, in, out, def_params) \
+#define TRUTHTABLE_START(cname, in, out, def_params)                           \
 	{ \
-		netlist::tt_desc desc; \
-		desc.name = #cname ; \
-		desc.ni = in; \
-		desc.no = out; \
-		desc.def_param = def_params; \
-		desc.family = "";
+		netlist::tt_desc desc;                                                 \
+		desc.name = #cname ;                                                   \
+		desc.ni = in;                                                          \
+		desc.no = out;                                                         \
+		desc.family = "";                                                      \
+		auto props(netlist::factory::properties(def_params, PSOURCELOC()));
 
 #define TT_HEAD(x) \
 		desc.desc.emplace_back(x);
@@ -126,7 +128,7 @@ void NETLIST_NAME(name)(netlist::nlparse_t &setup)                             \
 		desc.family = x;
 
 #define TRUTHTABLE_END() \
-		setup.truthtable_create(desc, PSOURCELOC());       \
+		setup.truthtable_create(desc, std::move(props)); \
 	}
 
 namespace netlist
@@ -160,7 +162,6 @@ namespace netlist
 		pstring name;
 		unsigned long ni;
 		unsigned long no;
-		pstring def_param;
 		std::vector<pstring> desc;
 		pstring family;
 	};
@@ -309,7 +310,7 @@ namespace netlist
 			register_param(param, static_cast<nl_fptype>(value));
 		}
 
-		void register_lib_entry(const pstring &name, const pstring &paramdef, plib::source_location &&sourceloc);
+		void register_lib_entry(const pstring &name, factory::properties &&props);
 
 		void register_frontier(const pstring &attach, const pstring &r_IN, const pstring &r_OUT);
 
@@ -323,7 +324,7 @@ namespace netlist
 			m_sources.add_source(std::move(src));
 		}
 
-		void truthtable_create(tt_desc &desc, plib::source_location &&sourceloc);
+		void truthtable_create(tt_desc &desc, factory::properties &&props);
 
 		// handle namespace