diff --git a/src/mame/drivers/fidelmcs48.cpp b/src/mame/drivers/fidelmcs48.cpp
index f7da11afce8..6cb818e209e 100644
--- a/src/mame/drivers/fidelmcs48.cpp
+++ b/src/mame/drivers/fidelmcs48.cpp
@@ -45,12 +45,15 @@ class fidelmcs48_state : public fidelbase_state
 {
 public:
 	fidelmcs48_state(const machine_config &mconfig, device_type type, const char *tag) :
-		fidelbase_state(mconfig, type, tag)
+		fidelbase_state(mconfig, type, tag),
+		m_maincpu(*this, "maincpu")
 	{ }
 
 	void sc6(machine_config &config);
 
 private:
+	required_device<mcs48_cpu_device> m_maincpu;
+
 	// SC6
 	void sc6_prepare_display();
 	DECLARE_WRITE8_MEMBER(sc6_mux_w);
@@ -180,13 +183,13 @@ INPUT_PORTS_END
 void fidelmcs48_state::sc6(machine_config &config)
 {
 	/* basic machine hardware */
-	i8040_device &maincpu(I8040(config, m_maincpu, 11_MHz_XTAL));
-	maincpu.set_addrmap(AS_PROGRAM, &fidelmcs48_state::sc6_map);
-	maincpu.p2_out_cb().set(FUNC(fidelmcs48_state::sc6_mux_w));
-	maincpu.p1_in_cb().set(FUNC(fidelmcs48_state::sc6_input_r));
-	maincpu.p1_out_cb().set(FUNC(fidelmcs48_state::sc6_select_w));
-	maincpu.t0_in_cb().set(FUNC(fidelmcs48_state::sc6_input6_r));
-	maincpu.t1_in_cb().set(FUNC(fidelmcs48_state::sc6_input7_r));
+	I8040(config, m_maincpu, 11_MHz_XTAL);
+	m_maincpu->set_addrmap(AS_PROGRAM, &fidelmcs48_state::sc6_map);
+	m_maincpu->p2_out_cb().set(FUNC(fidelmcs48_state::sc6_mux_w));
+	m_maincpu->p1_in_cb().set(FUNC(fidelmcs48_state::sc6_input_r));
+	m_maincpu->p1_out_cb().set(FUNC(fidelmcs48_state::sc6_select_w));
+	m_maincpu->t0_in_cb().set(FUNC(fidelmcs48_state::sc6_input6_r));
+	m_maincpu->t1_in_cb().set(FUNC(fidelmcs48_state::sc6_input7_r));
 
 	TIMER(config, "display_decay").configure_periodic(FUNC(fidelbase_state::display_decay_tick), attotime::from_msec(1));
 	config.set_default_layout(layout_fidel_sc6);
diff --git a/src/mame/drivers/fidelz80.cpp b/src/mame/drivers/fidelz80.cpp
index ac9ef521266..a016e8c4c45 100644
--- a/src/mame/drivers/fidelz80.cpp
+++ b/src/mame/drivers/fidelz80.cpp
@@ -37,10 +37,10 @@
     - Fidelity Challenger Printer - thermal printer, MCU=D8048C243
 
     Program/data cartridges, for various boards, some cross-compatible:
-    - CAC: Challenger Advanced Chess - 8KB 101-1038A01
     - CB9: Challenger Book Openings 1 - 8KB (label not known)
     - CB16: Challenger Book Openings 2 - 8+8KB 101-1042A01,02
-    - others are alt. titles of these?
+	- *CG64: 64 Greatest Games
+	- *EOA-EOE: Challenger Book Openings - Chess Encyclopedia A-E (5 modules)
 
     Board hardware descriptions below.
     Detailed RE work done by Kevin 'kevtris' Horton, except where noted
diff --git a/src/mame/drivers/novag68k.cpp b/src/mame/drivers/novag68k.cpp
index c153e2af0fa..ae0b9daff4a 100644
--- a/src/mame/drivers/novag68k.cpp
+++ b/src/mame/drivers/novag68k.cpp
@@ -11,7 +11,7 @@
     such as Arena(in editmode).
 
     TODO:
-    - RS232 port
+    - RS232 port (when connected, I'm only getting "New Game")
 
 ******************************************************************************
 
@@ -43,8 +43,8 @@ Scorpio 68000 hardware is very similar, but with chessboard buttons and side led
 class novag68k_state : public novagbase_state
 {
 public:
-	novag68k_state(const machine_config &mconfig, device_type type, const char *tag)
-		: novagbase_state(mconfig, type, tag)
+	novag68k_state(const machine_config &mconfig, device_type type, const char *tag) :
+		novagbase_state(mconfig, type, tag)
 	{ }
 
 	void diablo68k(machine_config &config);
diff --git a/src/mame/drivers/novagmcs48.cpp b/src/mame/drivers/novagmcs48.cpp
index a29f07ba89e..69fa328c2f6 100644
--- a/src/mame/drivers/novagmcs48.cpp
+++ b/src/mame/drivers/novagmcs48.cpp
@@ -42,7 +42,8 @@ class novagmcs48_state : public novagbase_state
 {
 public:
 	novagmcs48_state(const machine_config &mconfig, device_type type, const char *tag) :
-		novagbase_state(mconfig, type, tag)
+		novagbase_state(mconfig, type, tag),
+		m_maincpu(*this, "maincpu")
 	{ }
 
 	void presto(machine_config &config);
@@ -51,6 +52,8 @@ public:
 	DECLARE_INPUT_CHANGED_MEMBER(octo_cpu_freq);
 
 private:
+	required_device<mcs48_cpu_device> m_maincpu;
+
 	// Presto/Octo
 	DECLARE_WRITE8_MEMBER(presto_mux_w);
 	DECLARE_WRITE8_MEMBER(presto_control_w);
@@ -150,10 +153,10 @@ INPUT_CHANGED_MEMBER(novagmcs48_state::octo_cpu_freq)
 void novagmcs48_state::presto(machine_config &config)
 {
 	/* basic machine hardware */
-	i8049_device &maincpu(I8049(config, m_maincpu, 6000000)); // LC circuit, measured 6MHz
-	maincpu.p1_in_cb().set(FUNC(novagmcs48_state::presto_input_r));
-	maincpu.p2_out_cb().set(FUNC(novagmcs48_state::presto_control_w));
-	maincpu.bus_out_cb().set(FUNC(novagmcs48_state::presto_mux_w));
+	I8049(config, m_maincpu, 6000000); // LC circuit, measured 6MHz
+	m_maincpu->p1_in_cb().set(FUNC(novagmcs48_state::presto_input_r));
+	m_maincpu->p2_out_cb().set(FUNC(novagmcs48_state::presto_control_w));
+	m_maincpu->bus_out_cb().set(FUNC(novagmcs48_state::presto_mux_w));
 
 	TIMER(config, "display_decay").configure_periodic(FUNC(novagmcs48_state::display_decay_tick), attotime::from_msec(1));
 	config.set_default_layout(layout_novag_presto);