diff --git a/src/devices/bus/ti99/peb/peribox.cpp b/src/devices/bus/ti99/peb/peribox.cpp
index 3fc6531c017..8fc821f9978 100644
--- a/src/devices/bus/ti99/peb/peribox.cpp
+++ b/src/devices/bus/ti99/peb/peribox.cpp
@@ -491,22 +491,22 @@ void peribox_device::device_config_complete()
 }
 
 SLOT_INTERFACE_START( peribox_slot )
-	SLOT_INTERFACE("32kmem", TI99_32KMEM)
+	SLOT_INTERFACE("32kmem",   TI99_32KMEM)
 	SLOT_INTERFACE("myarcmem", TI99_MYARCMEM)
-	SLOT_INTERFACE("samsmem", TI99_SAMSMEM)
-	SLOT_INTERFACE("pcode", TI99_P_CODE)
-	SLOT_INTERFACE("hsgpl", TI99_HSGPL)
-	SLOT_INTERFACE("tirs232", TI99_RS232)
-	SLOT_INTERFACE("speech", TI99_SPEECH)
-	SLOT_INTERFACE("horizon", TI99_HORIZON)
-	SLOT_INTERFACE("ide", TI99_IDE)
-	SLOT_INTERFACE("usbsm", TI99_USBSM)
-	SLOT_INTERFACE("bwg", TI99_BWG)
-	SLOT_INTERFACE("hfdc", TI99_HFDC)
-	SLOT_INTERFACE("tifdc", TI99_FDC)
+	SLOT_INTERFACE("samsmem",  TI99_SAMSMEM)
+	SLOT_INTERFACE("pcode",    TI99_P_CODE)
+	SLOT_INTERFACE("hsgpl",    TI99_HSGPL)
+	SLOT_INTERFACE("tirs232",  TI99_RS232)
+	SLOT_INTERFACE("speech",   TI99_SPEECH)
+	SLOT_INTERFACE("horizon",  TI99_HORIZON)
+	SLOT_INTERFACE("ide",      TI99_IDE)
+	SLOT_INTERFACE("usbsm",    TI99_USBSM)
+	SLOT_INTERFACE("bwg",      TI99_BWG)
+	SLOT_INTERFACE("hfdc",     TI99_HFDC)
+	SLOT_INTERFACE("tifdc",    TI99_FDC)
 SLOT_INTERFACE_END
 
-MACHINE_CONFIG_START( peribox_device )
+MACHINE_CONFIG_MEMBER( peribox_device::device_add_mconfig )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT2, peribox_slot )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT3, peribox_slot )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT4, peribox_slot )
@@ -516,11 +516,6 @@ MACHINE_CONFIG_START( peribox_device )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT8, peribox_slot )
 MACHINE_CONFIG_END
 
-machine_config_constructor peribox_device::device_mconfig_additions() const
-{
-	return MACHINE_CONFIG_NAME( peribox_device );
-}
-
 /****************************************************************************
     A variant of the box used for the TI-99/4A with EVPC.
 *****************************************************************************/
@@ -532,23 +527,23 @@ peribox_ev_device::peribox_ev_device(const machine_config &mconfig, const char *
 }
 
 SLOT_INTERFACE_START( peribox_slotv )
-	SLOT_INTERFACE("32kmem", TI99_32KMEM)
-	SLOT_INTERFACE("evpc", TI99_EVPC )
+	SLOT_INTERFACE("evpc",     TI99_EVPC )
+	SLOT_INTERFACE("32kmem",   TI99_32KMEM)
 	SLOT_INTERFACE("myarcmem", TI99_MYARCMEM)
-	SLOT_INTERFACE("samsmem", TI99_SAMSMEM)
-	SLOT_INTERFACE("pcode", TI99_P_CODE)
-	SLOT_INTERFACE("hsgpl", TI99_HSGPL)
-	SLOT_INTERFACE("tirs232", TI99_RS232)
-	SLOT_INTERFACE("speech", TI99_SPEECH)
-	SLOT_INTERFACE("horizon", TI99_HORIZON)
-	SLOT_INTERFACE("ide", TI99_IDE)
-	SLOT_INTERFACE("usbsm", TI99_USBSM)
-	SLOT_INTERFACE("bwg", TI99_BWG)
-	SLOT_INTERFACE("hfdc", TI99_HFDC)
-	SLOT_INTERFACE("tifdc", TI99_FDC)
+	SLOT_INTERFACE("samsmem",  TI99_SAMSMEM)
+	SLOT_INTERFACE("pcode",    TI99_P_CODE)
+	SLOT_INTERFACE("hsgpl",    TI99_HSGPL)
+	SLOT_INTERFACE("tirs232",  TI99_RS232)
+	SLOT_INTERFACE("speech",   TI99_SPEECH)
+	SLOT_INTERFACE("horizon",  TI99_HORIZON)
+	SLOT_INTERFACE("ide",      TI99_IDE)
+	SLOT_INTERFACE("usbsm",    TI99_USBSM)
+	SLOT_INTERFACE("bwg",      TI99_BWG)
+	SLOT_INTERFACE("hfdc",     TI99_HFDC)
+	SLOT_INTERFACE("tifdc",    TI99_FDC)
 SLOT_INTERFACE_END
 
-MACHINE_CONFIG_START( peribox_ev_device )
+MACHINE_CONFIG_MEMBER( peribox_ev_device::device_add_mconfig )
 	MCFG_PERIBOX_SLOT_ADD_DEF( PEBSLOT2, peribox_slotv, "evpc" )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT3, peribox_slotv )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT4, peribox_slotv )
@@ -558,11 +553,6 @@ MACHINE_CONFIG_START( peribox_ev_device )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT8, peribox_slotv )
 MACHINE_CONFIG_END
 
-machine_config_constructor peribox_ev_device::device_mconfig_additions() const
-{
-	return MACHINE_CONFIG_NAME( peribox_ev_device );
-}
-
 /****************************************************************************
     A variant of the box used for the Geneve.
 *****************************************************************************/
@@ -580,17 +570,17 @@ peribox_gen_device::peribox_gen_device(const machine_config &mconfig, const char
 // logic (see bwg.c)
 
 SLOT_INTERFACE_START( peribox_slotg )
-	SLOT_INTERFACE("memex", TI99_MEMEX)
+	SLOT_INTERFACE("memex",   TI99_MEMEX)
 	SLOT_INTERFACE("tirs232", TI99_RS232)
-	SLOT_INTERFACE("speech", TI99_SPEECH)
+	SLOT_INTERFACE("speech",  TI99_SPEECH)
 	SLOT_INTERFACE("horizon", TI99_HORIZON)
-	SLOT_INTERFACE("ide", TI99_IDE)
-	SLOT_INTERFACE("usbsm", TI99_USBSM)
-	SLOT_INTERFACE("tifdc", TI99_FDC)
-	SLOT_INTERFACE("hfdc", TI99_HFDC)
+	SLOT_INTERFACE("ide",     TI99_IDE)
+	SLOT_INTERFACE("usbsm",   TI99_USBSM)
+	SLOT_INTERFACE("hfdc",    TI99_HFDC)
+	SLOT_INTERFACE("tifdc",   TI99_FDC)
 SLOT_INTERFACE_END
 
-MACHINE_CONFIG_START( peribox_gen_device )
+MACHINE_CONFIG_MEMBER( peribox_gen_device::device_add_mconfig )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT2, peribox_slotg )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT3, peribox_slotg )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT4, peribox_slotg )
@@ -600,11 +590,6 @@ MACHINE_CONFIG_START( peribox_gen_device )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT8, peribox_slotg )
 MACHINE_CONFIG_END
 
-machine_config_constructor peribox_gen_device::device_mconfig_additions() const
-{
-	return MACHINE_CONFIG_NAME( peribox_gen_device );
-}
-
 /****************************************************************************
     A variant of the box used for the SGCPU (aka TI-99/4P).
 *****************************************************************************/
@@ -616,20 +601,22 @@ peribox_sg_device::peribox_sg_device(const machine_config &mconfig, const char *
 }
 
 SLOT_INTERFACE_START( peribox_slotp )
-	SLOT_INTERFACE("pcode", TI99_P_CODE)
-	SLOT_INTERFACE("tirs232", TI99_RS232)
-	SLOT_INTERFACE("speech", TI99_SPEECH)
+	SLOT_INTERFACE("evpc",     TI99_EVPC )
 	SLOT_INTERFACE("myarcmem", TI99_MYARCMEM)
-	SLOT_INTERFACE("samsmem", TI99_SAMSMEM)
-	SLOT_INTERFACE("horizon", TI99_HORIZON)
-	SLOT_INTERFACE("ide", TI99_IDE)
-	SLOT_INTERFACE("usbsm", TI99_USBSM)
-	SLOT_INTERFACE("bwg", TI99_BWG)
-	SLOT_INTERFACE("hfdc", TI99_HFDC)
-	SLOT_INTERFACE("tifdc", TI99_FDC)
+	SLOT_INTERFACE("samsmem",  TI99_SAMSMEM)
+	SLOT_INTERFACE("pcode",    TI99_P_CODE)
+	SLOT_INTERFACE("hsgpl",    TI99_HSGPL)
+	SLOT_INTERFACE("tirs232",  TI99_RS232)
+	SLOT_INTERFACE("speech",   TI99_SPEECH)
+	SLOT_INTERFACE("horizon",  TI99_HORIZON)
+	SLOT_INTERFACE("ide",      TI99_IDE)
+	SLOT_INTERFACE("usbsm",    TI99_USBSM)
+	SLOT_INTERFACE("bwg",      TI99_BWG)
+	SLOT_INTERFACE("hfdc",     TI99_HFDC)
+	SLOT_INTERFACE("tifdc",    TI99_FDC)
 SLOT_INTERFACE_END
 
-MACHINE_CONFIG_START( peribox_sg_device )
+MACHINE_CONFIG_MEMBER( peribox_sg_device::device_add_mconfig )
 	MCFG_PERIBOX_SLOT_ADD_DEF( PEBSLOT2, peribox_slotp, "evpc" )
 	MCFG_PERIBOX_SLOT_ADD_DEF( PEBSLOT3, peribox_slotp, "hsgpl" )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT4, peribox_slotp )
@@ -639,11 +626,6 @@ MACHINE_CONFIG_START( peribox_sg_device )
 	MCFG_PERIBOX_SLOT_ADD( PEBSLOT8, peribox_slotp )
 MACHINE_CONFIG_END
 
-machine_config_constructor peribox_sg_device::device_mconfig_additions() const
-{
-	return MACHINE_CONFIG_NAME( peribox_sg_device );
-}
-
 /***************************************************************************
     Implementation of a slot within the box.
 ****************************************************************************/
diff --git a/src/devices/bus/ti99/peb/peribox.h b/src/devices/bus/ti99/peb/peribox.h
index 182c5aac909..df69a83e243 100644
--- a/src/devices/bus/ti99/peb/peribox.h
+++ b/src/devices/bus/ti99/peb/peribox.h
@@ -69,7 +69,7 @@ protected:
 	virtual void device_start() override;
 	virtual void device_config_complete() override;
 
-	virtual machine_config_constructor device_mconfig_additions() const override;
+	virtual void device_add_mconfig(machine_config &config) override;
 
 	// Next three methods call back the console via slot 1
 	devcb_write_line m_slot1_inta;   // INTA line (Box to console)
@@ -118,7 +118,7 @@ public:
 	peribox_sg_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
 
 protected:
-	virtual machine_config_constructor device_mconfig_additions() const override;
+	virtual void device_add_mconfig(machine_config &config) override;
 };
 
 /*
@@ -130,7 +130,7 @@ public:
 	peribox_ev_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
 
 protected:
-	virtual machine_config_constructor device_mconfig_additions() const override;
+	virtual void device_add_mconfig(machine_config &config) override;
 };
 
 
@@ -143,7 +143,7 @@ public:
 	peribox_gen_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
 
 protected:
-	virtual machine_config_constructor device_mconfig_additions() const override;
+	virtual void device_add_mconfig(machine_config &config) override;
 };
 
 /*****************************************************************************