diff --git a/src/mame/drivers/segag80r.cpp b/src/mame/drivers/segag80r.cpp
index fb1e11d550a..abeb23cc366 100644
--- a/src/mame/drivers/segag80r.cpp
+++ b/src/mame/drivers/segag80r.cpp
@@ -885,7 +885,7 @@ static MACHINE_CONFIG_DERIVED( monsterb, g80r_base )
 MACHINE_CONFIG_END
 
 static MACHINE_CONFIG_DERIVED( monster2, monsterb )
-	MCFG_CPU_REPLACE("maincpu", SEGA_CPU_MONSTER2, VIDEO_CLOCK/4)
+	MCFG_CPU_REPLACE("maincpu", SEGA_315_SPAT, VIDEO_CLOCK/4)
 	MCFG_CPU_PROGRAM_MAP(main_map)
 	MCFG_CPU_IO_MAP(main_ppi8255_portmap)
 	MCFG_CPU_VBLANK_INT_DRIVER("screen", segag80r_state,  segag80r_vblank_start)
diff --git a/src/mame/drivers/senjyo.cpp b/src/mame/drivers/senjyo.cpp
index 057a03118a9..a9e3972c089 100644
--- a/src/mame/drivers/senjyo.cpp
+++ b/src/mame/drivers/senjyo.cpp
@@ -601,7 +601,7 @@ MACHINE_CONFIG_END
 
 
 static MACHINE_CONFIG_DERIVED( senjyox_e, senjyo )
-	MCFG_CPU_REPLACE("maincpu", SEGA_CPU_STARFORE, 4000000)   /* 4 MHz? */
+	MCFG_CPU_REPLACE("maincpu", SEGA_315_5015, 4000000)   /* 4 MHz? */
 	MCFG_CPU_PROGRAM_MAP(senjyo_map)
 	MCFG_CPU_DECRYPTED_OPCODES_MAP(decrypted_opcodes_map)
 	MCFG_CPU_VBLANK_INT_DRIVER("screen", senjyo_state, irq0_line_assert)
@@ -609,7 +609,7 @@ static MACHINE_CONFIG_DERIVED( senjyox_e, senjyo )
 MACHINE_CONFIG_END
 
 static MACHINE_CONFIG_DERIVED( senjyox_a, senjyo )
-	MCFG_CPU_REPLACE("maincpu", SEGA_CPU_STARFORA, 4000000)   /* 4 MHz? */
+	MCFG_CPU_REPLACE("maincpu", SEGA_CPU_YAMATO, 4000000)   /* 4 MHz? */
 	MCFG_CPU_PROGRAM_MAP(senjyo_map)
 	MCFG_CPU_DECRYPTED_OPCODES_MAP(decrypted_opcodes_map)
 	MCFG_CPU_VBLANK_INT_DRIVER("screen", senjyo_state, irq0_line_assert)
diff --git a/src/mame/drivers/sg1000a.cpp b/src/mame/drivers/sg1000a.cpp
index 40ce1925ba5..0e43b6c527b 100644
--- a/src/mame/drivers/sg1000a.cpp
+++ b/src/mame/drivers/sg1000a.cpp
@@ -291,7 +291,7 @@ static MACHINE_CONFIG_START( sg1000a, sg1000a_state )
 MACHINE_CONFIG_END
 
 static MACHINE_CONFIG_DERIVED( sg1000ax, sg1000a )
-	MCFG_CPU_REPLACE("maincpu", SEGA_CPU_CHWRESTL, XTAL_3_579545MHz)
+	MCFG_CPU_REPLACE("maincpu", SEGA_315_5033, XTAL_3_579545MHz)
 	MCFG_CPU_PROGRAM_MAP(program_map)
 	MCFG_CPU_IO_MAP(io_map)
 	MCFG_CPU_DECRYPTED_OPCODES_MAP(decrypted_opcodes_map)
diff --git a/src/mame/machine/segacrpt_device.cpp b/src/mame/machine/segacrpt_device.cpp
index c5bdbdcb453..9eb628e306d 100644
--- a/src/mame/machine/segacrpt_device.cpp
+++ b/src/mame/machine/segacrpt_device.cpp
@@ -280,13 +280,9 @@ const device_type SEGA_315_5133 = &device_creator<sega_315_5133_device>; // NOT
 const device_type SEGA_CPU_BUCKROG = &device_creator<sega_cpu_buckrog_device>;
 const device_type SEGA_CPU_SZAXXON = &device_creator<sega_cpu_szaxxon_device>;
 const device_type SEGA_CPU_FUTSPY =  &device_creator<sega_cpu_futspy_device>;
-const device_type SEGA_CPU_CHWRESTL =  &device_creator<sega_cpu_chwrestl_device>;
 const device_type SEGA_CPU_YAMATO =  &device_creator<sega_cpu_yamato_device>;
 const device_type SEGA_CPU_PENGO =  &device_creator<sega_cpu_pengo_device>;
-const device_type SEGA_CPU_STARFORE =  &device_creator<sega_cpu_starfore_device>;
-const device_type SEGA_CPU_STARFORA =  &device_creator<sega_cpu_starfora_device>;
 const device_type SEGA_CPU_PBACTIO4 =  &device_creator<sega_cpu_pbactio4_device>;
-const device_type SEGA_CPU_MONSTER2 =  &device_creator<sega_cpu_monster2_device>;
 const device_type SEGA_CPU_SINBADM =  &device_creator<sega_cpu_sinbadm_device>;
 const device_type SEGA_CPU_JONGKYO =  &device_creator<sega_cpu_jongkyo_device>;
 
@@ -944,34 +940,6 @@ void sega_cpu_futspy_device::decrypt()
 
 
 
-sega_cpu_chwrestl_device::sega_cpu_chwrestl_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : segacrpt_z80_device(mconfig, tag, owner, clock) {}
-void sega_cpu_chwrestl_device::decrypt()
-{
-	static const UINT8 convtable[32][4] =
-	{
-		/*       opcode                   data                     address      */
-		/*  A    B    C    D         A    B    C    D                           */
-		{ 0x28,0x08,0xa8,0x88 }, { 0x88,0x80,0x08,0x00 },   /* ...0...0...0...0 */
-		{ 0x28,0x08,0xa8,0x88 }, { 0x28,0xa8,0x08,0x88 },   /* ...0...0...0...1 */
-		{ 0x88,0x80,0x08,0x00 }, { 0x88,0x08,0x80,0x00 },   /* ...0...0...1...0 */
-		{ 0x88,0x08,0x80,0x00 }, { 0x28,0xa8,0x08,0x88 },   /* ...0...0...1...1 */
-		{ 0x28,0x08,0xa8,0x88 }, { 0x88,0x80,0x08,0x00 },   /* ...0...1...0...0 */
-		{ 0x88,0x80,0x08,0x00 }, { 0x88,0x80,0x08,0x00 },   /* ...0...1...0...1 */
-		{ 0x88,0x08,0x80,0x00 }, { 0x88,0x08,0x80,0x00 },   /* ...0...1...1...0 */
-		{ 0xa0,0x80,0xa8,0x88 }, { 0xa0,0x80,0xa8,0x88 },   /* ...0...1...1...1 */
-		{ 0x80,0xa0,0x00,0x20 }, { 0x28,0x08,0xa8,0x88 },   /* ...1...0...0...0 */
-		{ 0x28,0xa8,0x08,0x88 }, { 0x28,0x08,0xa8,0x88 },   /* ...1...0...0...1 */
-		{ 0x80,0xa0,0x00,0x20 }, { 0x80,0xa0,0x00,0x20 },   /* ...1...0...1...0 */
-		{ 0x28,0xa8,0x08,0x88 }, { 0x80,0xa0,0x00,0x20 },   /* ...1...0...1...1 */
-		{ 0xa0,0x80,0xa8,0x88 }, { 0x28,0x08,0xa8,0x88 },   /* ...1...1...0...0 */
-		{ 0x80,0xa0,0x00,0x20 }, { 0xa0,0x80,0xa8,0x88 },   /* ...1...1...0...1 */
-		{ 0xa0,0x80,0xa8,0x88 }, { 0x80,0xa0,0x00,0x20 },   /* ...1...1...1...0 */
-		{ 0xa0,0x80,0xa8,0x88 }, { 0xa0,0x80,0xa8,0x88 }    /* ...1...1...1...1 */
-	};
-
-	decode(m_region_ptr, m_decrypted_ptr, m_decode_size, convtable, m_numbanks, m_banksize);
-}
-
 sega_cpu_yamato_device::sega_cpu_yamato_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : segacrpt_z80_device(mconfig, tag, owner, clock) {}
 void sega_cpu_yamato_device::decrypt()
 {
@@ -1032,63 +1000,8 @@ void sega_cpu_pengo_device::decrypt()
 	decode(m_region_ptr, m_decrypted_ptr, m_decode_size, convtable, m_numbanks, m_banksize);
 }
 
-sega_cpu_starfore_device::sega_cpu_starfore_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : segacrpt_z80_device(mconfig, tag, owner, clock) {}
-void sega_cpu_starfore_device::decrypt()
-{
 
-	static const UINT8 convtable[32][4] =
-	{
-		/*       opcode                   data                     address      */
-		/*  A    B    C    D         A    B    C    D                           */
-		{ 0x20,0x00,0xa0,0x80 }, { 0xa8,0xa0,0x88,0x80 },   /* ...0...0...0...0 */
-		{ 0x20,0x00,0xa0,0x80 }, { 0xa8,0xa0,0x88,0x80 },   /* ...0...0...0...1 */
-		{ 0x20,0x00,0xa0,0x80 }, { 0xa8,0xa0,0x88,0x80 },   /* ...0...0...1...0 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0xa8,0x88 },   /* ...0...0...1...1 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0xa8,0x88 },   /* ...0...1...0...0 */
-		{ 0x20,0x00,0xa0,0x80 }, { 0xa8,0xa0,0x88,0x80 },   /* ...0...1...0...1 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0xa8,0x88 },   /* ...0...1...1...0 */
-		{ 0x28,0xa8,0x08,0x88 }, { 0x88,0x80,0x08,0x00 },   /* ...0...1...1...1 */
-		{ 0x20,0x00,0xa0,0x80 }, { 0xa8,0xa0,0x88,0x80 },   /* ...1...0...0...0 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0xa8,0x88 },   /* ...1...0...0...1 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0xa8,0x88 },   /* ...1...0...1...0 */
-		{ 0x20,0x00,0xa0,0x80 }, { 0xa8,0xa0,0x88,0x80 },   /* ...1...0...1...1 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0xa8,0x88 },   /* ...1...1...0...0 */
-		{ 0x28,0xa8,0x08,0x88 }, { 0x88,0x80,0x08,0x00 },   /* ...1...1...0...1 */
-		{ 0x20,0x00,0xa0,0x80 }, { 0xa8,0xa0,0x88,0x80 },   /* ...1...1...1...0 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0xa8,0x88 }    /* ...1...1...1...1 */
-	};
 
-	decode(m_region_ptr, m_decrypted_ptr, m_decode_size, convtable, m_numbanks, m_banksize);
-}
-
-sega_cpu_starfora_device::sega_cpu_starfora_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : segacrpt_z80_device(mconfig, tag, owner, clock) {}
-void sega_cpu_starfora_device::decrypt()
-{
-
-	static const UINT8 convtable[32][4] =
-	{
-		/*       opcode                   data                     address      */
-		/*  A    B    C    D         A    B    C    D                           */
-		{ 0x88,0xa8,0x08,0x28 }, { 0x88,0xa8,0x80,0xa0 },   /* ...0...0...0...0 */
-		{ 0x20,0xa0,0x28,0xa8 }, { 0x88,0xa8,0x80,0xa0 },   /* ...0...0...0...1 */
-		{ 0x88,0xa8,0x80,0xa0 }, { 0x88,0xa8,0x80,0xa0 },   /* ...0...0...1...0 */
-		{ 0x88,0xa8,0x80,0xa0 }, { 0x20,0xa0,0x28,0xa8 },   /* ...0...0...1...1 */
-		{ 0x88,0xa8,0x08,0x28 }, { 0x88,0xa8,0x08,0x28 },   /* ...0...1...0...0 */
-		{ 0x88,0xa8,0x80,0xa0 }, { 0x88,0xa8,0x80,0xa0 },   /* ...0...1...0...1 */
-		{ 0x20,0xa0,0x28,0xa8 }, { 0x20,0xa0,0x28,0xa8 },   /* ...0...1...1...0 */
-		{ 0x88,0xa8,0x80,0xa0 }, { 0x88,0xa8,0x80,0xa0 },   /* ...0...1...1...1 */
-		{ 0x20,0xa0,0x28,0xa8 }, { 0x88,0xa8,0x08,0x28 },   /* ...1...0...0...0 */
-		{ 0x20,0xa0,0x28,0xa8 }, { 0x28,0x20,0xa8,0xa0 },   /* ...1...0...0...1 */
-		{ 0xa0,0x20,0x80,0x00 }, { 0x20,0xa0,0x28,0xa8 },   /* ...1...0...1...0 */
-		{ 0x28,0x20,0xa8,0xa0 }, { 0x20,0xa0,0x28,0xa8 },   /* ...1...0...1...1 */
-		{ 0x20,0xa0,0x28,0xa8 }, { 0x88,0xa8,0x08,0x28 },   /* ...1...1...0...0 */
-		{ 0x88,0xa8,0x08,0x28 }, { 0x88,0xa8,0x08,0x28 },   /* ...1...1...0...1 */
-		{ 0xa0,0x20,0x80,0x00 }, { 0x88,0x08,0x80,0x00 },   /* ...1...1...1...0 */
-		{ 0x20,0xa0,0x28,0xa8 }, { 0x00,0x08,0x20,0x28 }    /* ...1...1...1...1 */
-	};
-
-	decode(m_region_ptr, m_decrypted_ptr, m_decode_size, convtable, m_numbanks, m_banksize);
-}
 
 sega_cpu_pbactio4_device::sega_cpu_pbactio4_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : segacrpt_z80_device(mconfig, tag, owner, clock) {}
 void sega_cpu_pbactio4_device::decrypt()
@@ -1118,33 +1031,6 @@ void sega_cpu_pbactio4_device::decrypt()
 	decode(m_region_ptr, m_decrypted_ptr, m_decode_size, convtable, m_numbanks, m_banksize);
 }
 
-sega_cpu_monster2_device::sega_cpu_monster2_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : segacrpt_z80_device(mconfig, tag, owner, clock) {}
-void sega_cpu_monster2_device::decrypt()
-{
-	static const UINT8 convtable[32][4] =
-	{
-		/*       opcode                   data                     address      */
-		/*  A    B    C    D         A    B    C    D                           */
-		{ 0x88,0x08,0x80,0x00 }, { 0x00,0x08,0x20,0x28 },   /* ...0...0...0...0 */
-		{ 0x28,0xa8,0x08,0x88 }, { 0x28,0xa8,0x08,0x88 },   /* ...0...0...0...1 */
-		{ 0x28,0x20,0xa8,0xa0 }, { 0x28,0x20,0xa8,0xa0 },   /* ...0...0...1...0 */
-		{ 0x88,0x08,0x80,0x00 }, { 0x88,0x08,0x80,0x00 },   /* ...0...0...1...1 */
-		{ 0x00,0x08,0x20,0x28 }, { 0x88,0x08,0x80,0x00 },   /* ...0...1...0...0 */
-		{ 0xa0,0x80,0x20,0x00 }, { 0x80,0x88,0x00,0x08 },   /* ...0...1...0...1 */
-		{ 0x88,0x08,0x80,0x00 }, { 0xa0,0x80,0x20,0x00 },   /* ...0...1...1...0 */
-		{ 0x88,0x08,0x80,0x00 }, { 0x28,0x20,0xa8,0xa0 },   /* ...0...1...1...1 */
-		{ 0x28,0xa8,0x08,0x88 }, { 0x80,0x88,0x00,0x08 },   /* ...1...0...0...0 */
-		{ 0x80,0x88,0x00,0x08 }, { 0x00,0x08,0x20,0x28 },   /* ...1...0...0...1 */
-		{ 0x28,0x20,0xa8,0xa0 }, { 0x28,0xa8,0x08,0x88 },   /* ...1...0...1...0 */
-		{ 0x00,0x08,0x20,0x28 }, { 0x80,0xa0,0x88,0xa8 },   /* ...1...0...1...1 */
-		{ 0x80,0x88,0x00,0x08 }, { 0xa0,0x80,0x20,0x00 },   /* ...1...1...0...0 */
-		{ 0x80,0xa0,0x88,0xa8 }, { 0xa0,0x80,0x20,0x00 },   /* ...1...1...0...1 */
-		{ 0xa0,0x80,0x20,0x00 }, { 0x80,0xa0,0x88,0xa8 },   /* ...1...1...1...0 */
-		{ 0x28,0x20,0xa8,0xa0 }, { 0x00,0x08,0x20,0x28 }    /* ...1...1...1...1 */
-	};
-
-	decode(m_region_ptr, m_decrypted_ptr, m_decode_size, convtable, m_numbanks, m_banksize);
-}
 
 sega_cpu_sinbadm_device::sega_cpu_sinbadm_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock) : segacrpt_z80_device(mconfig, tag, owner, clock) {}
 void sega_cpu_sinbadm_device::decrypt()
diff --git a/src/mame/machine/segacrpt_device.h b/src/mame/machine/segacrpt_device.h
index af589a7e2d2..c3935201a5a 100644
--- a/src/mame/machine/segacrpt_device.h
+++ b/src/mame/machine/segacrpt_device.h
@@ -220,13 +220,6 @@ protected:
 	virtual void decrypt() override;
 };
 
-class sega_cpu_chwrestl_device : public segacrpt_z80_device
-{
-public:
-	sega_cpu_chwrestl_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32);
-protected:
-	virtual void decrypt() override;
-};
 
 
 class sega_cpu_yamato_device : public segacrpt_z80_device
@@ -245,21 +238,7 @@ protected:
 	virtual void decrypt() override;
 };
 
-class sega_cpu_starfore_device : public segacrpt_z80_device
-{
-public:
-	sega_cpu_starfore_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32);
-protected:
-	virtual void decrypt() override;
-};
 
-class sega_cpu_starfora_device : public segacrpt_z80_device
-{
-public:
-	sega_cpu_starfora_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32);
-protected:
-	virtual void decrypt() override;
-};
 
 class sega_cpu_pbactio4_device : public segacrpt_z80_device
 {
@@ -269,14 +248,6 @@ protected:
 	virtual void decrypt() override;
 };
 
-class sega_cpu_monster2_device : public segacrpt_z80_device
-{
-public:
-	sega_cpu_monster2_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32);
-protected:
-	virtual void decrypt() override;
-};
-
 class sega_cpu_sinbadm_device : public segacrpt_z80_device
 {
 public:
@@ -314,13 +285,9 @@ extern const device_type SEGA_315_5133;
 extern const device_type SEGA_CPU_BUCKROG;
 extern const device_type SEGA_CPU_SZAXXON;
 extern const device_type SEGA_CPU_FUTSPY;
-extern const device_type SEGA_CPU_CHWRESTL;
 extern const device_type SEGA_CPU_YAMATO;
 extern const device_type SEGA_CPU_PENGO;
-extern const device_type SEGA_CPU_STARFORE;
-extern const device_type SEGA_CPU_STARFORA;
 extern const device_type SEGA_CPU_PBACTIO4;
-extern const device_type SEGA_CPU_MONSTER2;
 extern const device_type SEGA_CPU_SINBADM;
 extern const device_type SEGA_CPU_JONGKYO;