diff --git a/src/devices/bus/nubus/bootbug.cpp b/src/devices/bus/nubus/bootbug.cpp
index 447887dd032..af507307918 100644
--- a/src/devices/bus/nubus/bootbug.cpp
+++ b/src/devices/bus/nubus/bootbug.cpp
@@ -96,13 +96,11 @@ void nubus_bootbug_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, BOOTBUG_ROM_REGION);
 
 	slotspace = get_slotspace();
 
-	m_nubus->install_device(slotspace, slotspace+0xff, read32_delegate(FUNC(nubus_bootbug_device::dev_r), this), write32_delegate(FUNC(nubus_bootbug_device::dev_w), this));
+	nubus().install_device(slotspace, slotspace+0xff, read32_delegate(FUNC(nubus_bootbug_device::dev_r), this), write32_delegate(FUNC(nubus_bootbug_device::dev_w), this));
 }
 
 //-------------------------------------------------
diff --git a/src/devices/bus/nubus/nubus.cpp b/src/devices/bus/nubus/nubus.cpp
index 9a3fbdca25e..c4934cda302 100644
--- a/src/devices/bus/nubus/nubus.cpp
+++ b/src/devices/bus/nubus/nubus.cpp
@@ -273,38 +273,52 @@ void device_nubus_card_interface::static_set_nubus_tag(device_t &device, const c
 	nubus_card.m_nubus_slottag = slottag;
 }
 
-void device_nubus_card_interface::set_nubus_device()
+void device_nubus_card_interface::interface_pre_start()
 {
-	if (!strncmp(m_nubus_slottag, "pds030", 6))
+	if (!m_nubus)
 	{
-		m_slot = 0x9;   // '030 PDS slots phantom slot as NuBus slots $9, $A, and $B
-	}
-	else if (!strncmp(m_nubus_slottag, "lcpds", 6))
-	{
-		m_slot = 0xe;   // LC PDS slots phantom slot as NuBus slot $E
-	}
-	else
-	{
-		// extract the slot number from the last digit of the slot tag
-		int tlen = strlen(m_nubus_slottag);
-
-		if (m_nubus_slottag[tlen-1] == '9')
+		if (!strncmp(m_nubus_slottag, "pds030", 6))
 		{
-			m_slot = (m_nubus_slottag[tlen-1] - '9') + 9;
+			m_slot = 0x9;   // '030 PDS slots phantom slot as NuBus slots $9, $A, and $B
+		}
+		else if (!strncmp(m_nubus_slottag, "lcpds", 6))
+		{
+			m_slot = 0xe;   // LC PDS slots phantom slot as NuBus slot $E
 		}
 		else
 		{
-			m_slot = (m_nubus_slottag[tlen-1] - 'a') + 0xa;
+			// extract the slot number from the last digit of the slot tag
+			int tlen = strlen(m_nubus_slottag);
+
+			if (m_nubus_slottag[tlen-1] == '9')
+			{
+				m_slot = (m_nubus_slottag[tlen-1] - '9') + 9;
+			}
+			else
+			{
+				m_slot = (m_nubus_slottag[tlen-1] - 'a') + 0xa;
+			}
 		}
-	}
 
-	if (m_slot < 9 || m_slot > 0xe)
-	{
-		fatalerror("Slot %x out of range for Apple NuBus\n", m_slot);
-	}
+		if (m_slot < 9 || m_slot > 0xe)
+		{
+			fatalerror("Slot %x out of range for Apple NuBus\n", m_slot);
+		}
 
-	m_nubus = dynamic_cast<nubus_device *>(device().machine().device(m_nubus_tag));
-	m_nubus->add_nubus_card(this);
+		device_t *const bus = device().machine().device(m_nubus_tag);
+		if (!bus)
+		{
+			fatalerror("Can't find NuBus device %s\n", m_nubus_tag);
+		}
+
+		m_nubus = dynamic_cast<nubus_device *>(bus);
+		if (!m_nubus)
+		{
+			fatalerror("Device %s (%s) is not an instance of nubus_device\n", bus->tag(), bus->name());
+		}
+
+		nubus().add_nubus_card(this);
+	}
 }
 
 void device_nubus_card_interface::install_bank(offs_t start, offs_t end, const char *tag, uint8_t *data)
@@ -316,7 +330,7 @@ void device_nubus_card_interface::install_bank(offs_t start, offs_t end, const c
 	strcat(bank, "_");
 	strcat(bank, m_nubus_slottag);
 
-	m_nubus->install_bank(start, end, bank, data);
+	nubus().install_bank(start, end, bank, data);
 }
 
 void device_nubus_card_interface::install_declaration_rom(device_t *dev, const char *romregion, bool mirror_all_mb, bool reverse_rom)
@@ -464,12 +478,12 @@ void device_nubus_card_interface::install_declaration_rom(device_t *dev, const c
 	{
 		uint32_t off = 0;
 		while(off < 0x1000000) {
-			m_nubus->install_bank(addr + off, addr+off+romlen-1, bankname, &m_declaration_rom[0]);
+			nubus().install_bank(addr + off, addr+off+romlen-1, bankname, &m_declaration_rom[0]);
 			off += romlen;
 		}
 	}
 	else
 	{
-		m_nubus->install_bank(addr, addr+romlen-1, bankname, &m_declaration_rom[0]);
+		nubus().install_bank(addr, addr+romlen-1, bankname, &m_declaration_rom[0]);
 	}
 }
diff --git a/src/devices/bus/nubus/nubus.h b/src/devices/bus/nubus/nubus.h
index 8cc1a3bbbf2..2f7fc5c359a 100644
--- a/src/devices/bus/nubus/nubus.h
+++ b/src/devices/bus/nubus/nubus.h
@@ -161,21 +161,24 @@ public:
 	uint32_t get_slotspace() { return 0xf0000000 | (m_slot<<24); }
 	uint32_t get_super_slotspace() { return m_slot<<28; }
 
-	void raise_slot_irq() { m_nubus->set_irq_line(m_slot, ASSERT_LINE); }
-	void lower_slot_irq() { m_nubus->set_irq_line(m_slot, CLEAR_LINE); }
+	void raise_slot_irq() { nubus().set_irq_line(m_slot, ASSERT_LINE); }
+	void lower_slot_irq() { nubus().set_irq_line(m_slot, CLEAR_LINE); }
 
 	// inline configuration
 	static void static_set_nubus_tag(device_t &device, const char *tag, const char *slottag);
 
 protected:
 	device_nubus_card_interface(const machine_config &mconfig, device_t &device);
+	virtual void interface_pre_start() override;
 
+	int slotno() const { assert(m_nubus); return m_slot; }
+	nubus_device &nubus() { assert(m_nubus); return *m_nubus; }
+
+private:
 	nubus_device  *m_nubus;
 	const char *m_nubus_tag, *m_nubus_slottag;
 	int m_slot;
 	std::vector<uint8_t> m_declaration_rom;
-
-private:
 	device_nubus_card_interface *m_next;
 };
 
diff --git a/src/devices/bus/nubus/nubus_48gc.cpp b/src/devices/bus/nubus/nubus_48gc.cpp
index dcab3a6b1bb..de2d52fb420 100644
--- a/src/devices/bus/nubus/nubus_48gc.cpp
+++ b/src/devices/bus/nubus/nubus_48gc.cpp
@@ -100,8 +100,6 @@ void jmfb_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, GC48_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -111,7 +109,7 @@ void jmfb_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	install_bank(slotspace, slotspace+VRAM_SIZE-1, "bank_48gc", &m_vram[0]);
 
-	m_nubus->install_device(slotspace+0x200000, slotspace+0x2003ff, read32_delegate(FUNC(jmfb_device::mac_48gc_r), this), write32_delegate(FUNC(jmfb_device::mac_48gc_w), this));
+	nubus().install_device(slotspace+0x200000, slotspace+0x2003ff, read32_delegate(FUNC(jmfb_device::mac_48gc_r), this), write32_delegate(FUNC(jmfb_device::mac_48gc_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_screen = nullptr;    // can we look this up now?
diff --git a/src/devices/bus/nubus/nubus_asntmc3b.cpp b/src/devices/bus/nubus/nubus_asntmc3b.cpp
index 733c0d41416..a7a16ebb194 100644
--- a/src/devices/bus/nubus/nubus_asntmc3b.cpp
+++ b/src/devices/bus/nubus/nubus_asntmc3b.cpp
@@ -101,8 +101,7 @@ void nubus_mac8390_device::device_start()
 	mac[0] = mac[1] = 0;  // avoid gcc warning
 	memcpy(m_prom, mac, 6);
 	m_dp83902->set_mac(mac);
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
+
 	install_declaration_rom(this, MAC8390_ROM_REGION, true);
 
 	slotspace = get_slotspace();
@@ -110,11 +109,11 @@ void nubus_mac8390_device::device_start()
 //  printf("[ASNTMC3NB %p] slotspace = %x\n", this, slotspace);
 
 	// TODO: move 24-bit mirroring down into nubus.c
-	uint32_t ofs_24bit = m_slot<<20;
-	m_nubus->install_device(slotspace+0xd0000, slotspace+0xdffff, read8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_r), this), write8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_w), this));
-	m_nubus->install_device(slotspace+0xe0000, slotspace+0xe003f, read32_delegate(FUNC(nubus_mac8390_device::en_r), this), write32_delegate(FUNC(nubus_mac8390_device::en_w), this));
-	m_nubus->install_device(slotspace+0xd0000+ofs_24bit, slotspace+0xdffff+ofs_24bit, read8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_r), this), write8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_w), this));
-	m_nubus->install_device(slotspace+0xe0000+ofs_24bit, slotspace+0xe003f+ofs_24bit, read32_delegate(FUNC(nubus_mac8390_device::en_r), this), write32_delegate(FUNC(nubus_mac8390_device::en_w), this));
+	uint32_t ofs_24bit = slotno()<<20;
+	nubus().install_device(slotspace+0xd0000, slotspace+0xdffff, read8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_r), this), write8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_w), this));
+	nubus().install_device(slotspace+0xe0000, slotspace+0xe003f, read32_delegate(FUNC(nubus_mac8390_device::en_r), this), write32_delegate(FUNC(nubus_mac8390_device::en_w), this));
+	nubus().install_device(slotspace+0xd0000+ofs_24bit, slotspace+0xdffff+ofs_24bit, read8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_r), this), write8_delegate(FUNC(nubus_mac8390_device::asntm3b_ram_w), this));
+	nubus().install_device(slotspace+0xe0000+ofs_24bit, slotspace+0xe003f+ofs_24bit, read32_delegate(FUNC(nubus_mac8390_device::en_r), this), write32_delegate(FUNC(nubus_mac8390_device::en_w), this));
 }
 
 //-------------------------------------------------
diff --git a/src/devices/bus/nubus/nubus_cb264.cpp b/src/devices/bus/nubus/nubus_cb264.cpp
index 1ea07a83838..1a819328e3c 100644
--- a/src/devices/bus/nubus/nubus_cb264.cpp
+++ b/src/devices/bus/nubus/nubus_cb264.cpp
@@ -85,8 +85,6 @@ void nubus_cb264_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, CB264_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -96,8 +94,8 @@ void nubus_cb264_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	install_bank(slotspace, slotspace+VRAM_SIZE-1, "bank_cb264", &m_vram[0]);
 
-	m_nubus->install_device(slotspace+0xff6000, slotspace+0xff60ff, read32_delegate(FUNC(nubus_cb264_device::cb264_r), this), write32_delegate(FUNC(nubus_cb264_device::cb264_w), this));
-	m_nubus->install_device(slotspace+0xff7000, slotspace+0xff70ff, read32_delegate(FUNC(nubus_cb264_device::cb264_ramdac_r), this), write32_delegate(FUNC(nubus_cb264_device::cb264_ramdac_w), this));
+	nubus().install_device(slotspace+0xff6000, slotspace+0xff60ff, read32_delegate(FUNC(nubus_cb264_device::cb264_r), this), write32_delegate(FUNC(nubus_cb264_device::cb264_w), this));
+	nubus().install_device(slotspace+0xff7000, slotspace+0xff70ff, read32_delegate(FUNC(nubus_cb264_device::cb264_ramdac_r), this), write32_delegate(FUNC(nubus_cb264_device::cb264_ramdac_w), this));
 }
 
 //-------------------------------------------------
diff --git a/src/devices/bus/nubus/nubus_image.cpp b/src/devices/bus/nubus/nubus_image.cpp
index 56b2ff3ff0c..285dae1cfbc 100644
--- a/src/devices/bus/nubus/nubus_image.cpp
+++ b/src/devices/bus/nubus/nubus_image.cpp
@@ -172,8 +172,6 @@ void nubus_image_device::device_start()
 	uint32_t slotspace;
 	uint32_t superslotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, IMAGE_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -181,13 +179,13 @@ void nubus_image_device::device_start()
 
 //  printf("[image %p] slotspace = %x, super = %x\n", this, slotspace, superslotspace);
 
-	m_nubus->install_device(slotspace, slotspace+3, read32_delegate(FUNC(nubus_image_device::image_r), this), write32_delegate(FUNC(nubus_image_device::image_w), this));
-	m_nubus->install_device(slotspace+4, slotspace+7, read32_delegate(FUNC(nubus_image_device::image_status_r), this), write32_delegate(FUNC(nubus_image_device::image_status_w), this));
-	m_nubus->install_device(slotspace+8, slotspace+11, read32_delegate(FUNC(nubus_image_device::file_cmd_r), this), write32_delegate(FUNC(nubus_image_device::file_cmd_w), this));
-	m_nubus->install_device(slotspace+12, slotspace+15, read32_delegate(FUNC(nubus_image_device::file_data_r), this), write32_delegate(FUNC(nubus_image_device::file_data_w), this));
-	m_nubus->install_device(slotspace+16, slotspace+19, read32_delegate(FUNC(nubus_image_device::file_len_r), this), write32_delegate(FUNC(nubus_image_device::file_len_w), this));
-	m_nubus->install_device(slotspace+20, slotspace+147, read32_delegate(FUNC(nubus_image_device::file_name_r), this), write32_delegate(FUNC(nubus_image_device::file_name_w), this));
-	m_nubus->install_device(superslotspace, superslotspace+((256*1024*1024)-1), read32_delegate(FUNC(nubus_image_device::image_super_r), this), write32_delegate(FUNC(nubus_image_device::image_super_w), this));
+	nubus().install_device(slotspace, slotspace+3, read32_delegate(FUNC(nubus_image_device::image_r), this), write32_delegate(FUNC(nubus_image_device::image_w), this));
+	nubus().install_device(slotspace+4, slotspace+7, read32_delegate(FUNC(nubus_image_device::image_status_r), this), write32_delegate(FUNC(nubus_image_device::image_status_w), this));
+	nubus().install_device(slotspace+8, slotspace+11, read32_delegate(FUNC(nubus_image_device::file_cmd_r), this), write32_delegate(FUNC(nubus_image_device::file_cmd_w), this));
+	nubus().install_device(slotspace+12, slotspace+15, read32_delegate(FUNC(nubus_image_device::file_data_r), this), write32_delegate(FUNC(nubus_image_device::file_data_w), this));
+	nubus().install_device(slotspace+16, slotspace+19, read32_delegate(FUNC(nubus_image_device::file_len_r), this), write32_delegate(FUNC(nubus_image_device::file_len_w), this));
+	nubus().install_device(slotspace+20, slotspace+147, read32_delegate(FUNC(nubus_image_device::file_name_r), this), write32_delegate(FUNC(nubus_image_device::file_name_w), this));
+	nubus().install_device(superslotspace, superslotspace+((256*1024*1024)-1), read32_delegate(FUNC(nubus_image_device::image_super_r), this), write32_delegate(FUNC(nubus_image_device::image_super_w), this));
 
 	m_image = subdevice<messimg_disk_image_device>(IMAGE_DISK0_TAG);
 
diff --git a/src/devices/bus/nubus/nubus_m2hires.cpp b/src/devices/bus/nubus/nubus_m2hires.cpp
index 6a76bd29ff8..b267ec4ef27 100644
--- a/src/devices/bus/nubus/nubus_m2hires.cpp
+++ b/src/devices/bus/nubus/nubus_m2hires.cpp
@@ -84,8 +84,6 @@ void nubus_m2hires_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, M2HIRES_ROM_REGION, true);
 
 	slotspace = get_slotspace();
@@ -95,9 +93,9 @@ void nubus_m2hires_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_m2hires_device::vram_r), this), write32_delegate(FUNC(nubus_m2hires_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_m2hires_device::vram_r), this), write32_delegate(FUNC(nubus_m2hires_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_m2hires_device::m2hires_r), this), write32_delegate(FUNC(nubus_m2hires_device::m2hires_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_m2hires_device::vram_r), this), write32_delegate(FUNC(nubus_m2hires_device::vram_w), this));
+	nubus().install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_m2hires_device::vram_r), this), write32_delegate(FUNC(nubus_m2hires_device::vram_w), this));
+	nubus().install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_m2hires_device::m2hires_r), this), write32_delegate(FUNC(nubus_m2hires_device::m2hires_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(479, 0), 0);
diff --git a/src/devices/bus/nubus/nubus_m2video.cpp b/src/devices/bus/nubus/nubus_m2video.cpp
index 9e998216078..2a1b820cee1 100644
--- a/src/devices/bus/nubus/nubus_m2video.cpp
+++ b/src/devices/bus/nubus/nubus_m2video.cpp
@@ -86,8 +86,6 @@ void nubus_m2video_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, M2VIDEO_ROM_REGION, true, true);
 
 	slotspace = get_slotspace();
@@ -97,9 +95,9 @@ void nubus_m2video_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_m2video_device::vram_r), this), write32_delegate(FUNC(nubus_m2video_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_m2video_device::vram_r), this), write32_delegate(FUNC(nubus_m2video_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_m2video_device::m2video_r), this), write32_delegate(FUNC(nubus_m2video_device::m2video_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_m2video_device::vram_r), this), write32_delegate(FUNC(nubus_m2video_device::vram_w), this));
+	nubus().install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_m2video_device::vram_r), this), write32_delegate(FUNC(nubus_m2video_device::vram_w), this));
+	nubus().install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_m2video_device::m2video_r), this), write32_delegate(FUNC(nubus_m2video_device::m2video_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(479, 0), 0);
diff --git a/src/devices/bus/nubus/nubus_radiustpd.cpp b/src/devices/bus/nubus/nubus_radiustpd.cpp
index 3fe40215d09..9b6749f92b2 100644
--- a/src/devices/bus/nubus/nubus_radiustpd.cpp
+++ b/src/devices/bus/nubus/nubus_radiustpd.cpp
@@ -87,8 +87,6 @@ void nubus_radiustpd_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, RADIUSTPD_ROM_REGION, true, true);
 
 	slotspace = get_slotspace();
@@ -98,10 +96,10 @@ void nubus_radiustpd_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_radiustpd_device::vram_r), this), write32_delegate(FUNC(nubus_radiustpd_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_radiustpd_device::vram_r), this), write32_delegate(FUNC(nubus_radiustpd_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_radiustpd_device::radiustpd_r), this), write32_delegate(FUNC(nubus_radiustpd_device::radiustpd_w), this));
-	m_nubus->install_device(slotspace+0x980000, slotspace+0x9effff, read32_delegate(FUNC(nubus_radiustpd_device::radiustpd_r), this), write32_delegate(FUNC(nubus_radiustpd_device::radiustpd_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_radiustpd_device::vram_r), this), write32_delegate(FUNC(nubus_radiustpd_device::vram_w), this));
+	nubus().install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_radiustpd_device::vram_r), this), write32_delegate(FUNC(nubus_radiustpd_device::vram_w), this));
+	nubus().install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_radiustpd_device::radiustpd_r), this), write32_delegate(FUNC(nubus_radiustpd_device::radiustpd_w), this));
+	nubus().install_device(slotspace+0x980000, slotspace+0x9effff, read32_delegate(FUNC(nubus_radiustpd_device::radiustpd_r), this), write32_delegate(FUNC(nubus_radiustpd_device::radiustpd_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(479, 0), 0);
diff --git a/src/devices/bus/nubus/nubus_spec8.cpp b/src/devices/bus/nubus/nubus_spec8.cpp
index be1150eab1b..215ad07a1ab 100644
--- a/src/devices/bus/nubus/nubus_spec8.cpp
+++ b/src/devices/bus/nubus/nubus_spec8.cpp
@@ -89,8 +89,6 @@ void nubus_spec8s3_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, SPEC8S3_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -99,9 +97,9 @@ void nubus_spec8s3_device::device_start()
 
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_spec8s3_device::vram_r), this), write32_delegate(FUNC(nubus_spec8s3_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_spec8s3_device::vram_r), this), write32_delegate(FUNC(nubus_spec8s3_device::vram_w), this));
-	m_nubus->install_device(slotspace+0xd0000, slotspace+0xfffff, read32_delegate(FUNC(nubus_spec8s3_device::spec8s3_r), this), write32_delegate(FUNC(nubus_spec8s3_device::spec8s3_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_spec8s3_device::vram_r), this), write32_delegate(FUNC(nubus_spec8s3_device::vram_w), this));
+	nubus().install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_spec8s3_device::vram_r), this), write32_delegate(FUNC(nubus_spec8s3_device::vram_w), this));
+	nubus().install_device(slotspace+0xd0000, slotspace+0xfffff, read32_delegate(FUNC(nubus_spec8s3_device::spec8s3_r), this), write32_delegate(FUNC(nubus_spec8s3_device::spec8s3_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(767, 0), 0);
diff --git a/src/devices/bus/nubus/nubus_specpdq.cpp b/src/devices/bus/nubus/nubus_specpdq.cpp
index 05affbbad91..30012d26e64 100644
--- a/src/devices/bus/nubus/nubus_specpdq.cpp
+++ b/src/devices/bus/nubus/nubus_specpdq.cpp
@@ -103,8 +103,6 @@ void nubus_specpdq_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, SPECPDQ_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -113,8 +111,8 @@ void nubus_specpdq_device::device_start()
 
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_specpdq_device::vram_r), this), write32_delegate(FUNC(nubus_specpdq_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x400000, slotspace+0xfbffff, read32_delegate(FUNC(nubus_specpdq_device::specpdq_r), this), write32_delegate(FUNC(nubus_specpdq_device::specpdq_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_specpdq_device::vram_r), this), write32_delegate(FUNC(nubus_specpdq_device::vram_w), this));
+	nubus().install_device(slotspace+0x400000, slotspace+0xfbffff, read32_delegate(FUNC(nubus_specpdq_device::specpdq_r), this), write32_delegate(FUNC(nubus_specpdq_device::specpdq_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(843, 0), 0);
diff --git a/src/devices/bus/nubus/nubus_vikbw.cpp b/src/devices/bus/nubus/nubus_vikbw.cpp
index 7e59cf1fa06..040f452b2d2 100644
--- a/src/devices/bus/nubus/nubus_vikbw.cpp
+++ b/src/devices/bus/nubus/nubus_vikbw.cpp
@@ -81,8 +81,6 @@ void nubus_vikbw_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, VIKBW_ROM_REGION, true);
 
 	slotspace = get_slotspace();
@@ -93,8 +91,8 @@ void nubus_vikbw_device::device_start()
 	install_bank(slotspace+0x40000, slotspace+0x40000+VRAM_SIZE-1, "bank_vikbw", &m_vram[0]);
 	install_bank(slotspace+0x940000, slotspace+0x940000+VRAM_SIZE-1, "bank_vikbw2", &m_vram[0]);
 
-	m_nubus->install_device(slotspace, slotspace+3, read32_delegate(FUNC(nubus_vikbw_device::viking_enable_r), this), write32_delegate(FUNC(nubus_vikbw_device::viking_disable_w), this));
-	m_nubus->install_device(slotspace+0x80000, slotspace+0x80000+3, read32_delegate(FUNC(nubus_vikbw_device::viking_ack_r), this), write32_delegate(FUNC(nubus_vikbw_device::viking_ack_w), this));
+	nubus().install_device(slotspace, slotspace+3, read32_delegate(FUNC(nubus_vikbw_device::viking_enable_r), this), write32_delegate(FUNC(nubus_vikbw_device::viking_disable_w), this));
+	nubus().install_device(slotspace+0x80000, slotspace+0x80000+3, read32_delegate(FUNC(nubus_vikbw_device::viking_ack_r), this), write32_delegate(FUNC(nubus_vikbw_device::viking_ack_w), this));
 }
 
 //-------------------------------------------------
diff --git a/src/devices/bus/nubus/nubus_wsportrait.cpp b/src/devices/bus/nubus/nubus_wsportrait.cpp
index 58d906c3fbf..095c7aa781e 100644
--- a/src/devices/bus/nubus/nubus_wsportrait.cpp
+++ b/src/devices/bus/nubus/nubus_wsportrait.cpp
@@ -87,8 +87,6 @@ void nubus_wsportrait_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, WSPORTRAIT_ROM_REGION, true);
 
 	slotspace = get_slotspace();
@@ -98,9 +96,9 @@ void nubus_wsportrait_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_wsportrait_device::vram_r), this), write32_delegate(FUNC(nubus_wsportrait_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x900000, slotspace+0x900000+VRAM_SIZE-1, read32_delegate(FUNC(nubus_wsportrait_device::vram_r), this), write32_delegate(FUNC(nubus_wsportrait_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_wsportrait_device::wsportrait_r), this), write32_delegate(FUNC(nubus_wsportrait_device::wsportrait_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_wsportrait_device::vram_r), this), write32_delegate(FUNC(nubus_wsportrait_device::vram_w), this));
+	nubus().install_device(slotspace+0x900000, slotspace+0x900000+VRAM_SIZE-1, read32_delegate(FUNC(nubus_wsportrait_device::vram_r), this), write32_delegate(FUNC(nubus_wsportrait_device::vram_w), this));
+	nubus().install_device(slotspace+0x80000, slotspace+0xeffff, read32_delegate(FUNC(nubus_wsportrait_device::wsportrait_r), this), write32_delegate(FUNC(nubus_wsportrait_device::wsportrait_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(869, 0), 0);
diff --git a/src/devices/bus/nubus/pds30_30hr.cpp b/src/devices/bus/nubus/pds30_30hr.cpp
index f8b65e11452..b6ae942efb9 100644
--- a/src/devices/bus/nubus/pds30_30hr.cpp
+++ b/src/devices/bus/nubus/pds30_30hr.cpp
@@ -87,8 +87,6 @@ void nubus_xceed30hr_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, XCEED30HR_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -98,8 +96,8 @@ void nubus_xceed30hr_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_xceed30hr_device::vram_r), this), write32_delegate(FUNC(nubus_xceed30hr_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x800000, slotspace+0xefffff, read32_delegate(FUNC(nubus_xceed30hr_device::xceed30hr_r), this), write32_delegate(FUNC(nubus_xceed30hr_device::xceed30hr_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_xceed30hr_device::vram_r), this), write32_delegate(FUNC(nubus_xceed30hr_device::vram_w), this));
+	nubus().install_device(slotspace+0x800000, slotspace+0xefffff, read32_delegate(FUNC(nubus_xceed30hr_device::xceed30hr_r), this), write32_delegate(FUNC(nubus_xceed30hr_device::xceed30hr_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(479, 0), 0);
diff --git a/src/devices/bus/nubus/pds30_cb264.cpp b/src/devices/bus/nubus/pds30_cb264.cpp
index 0af9b486247..7741308dd6b 100644
--- a/src/devices/bus/nubus/pds30_cb264.cpp
+++ b/src/devices/bus/nubus/pds30_cb264.cpp
@@ -81,8 +81,6 @@ void nubus_cb264se30_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, CB264SE30_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -92,8 +90,8 @@ void nubus_cb264se30_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_cb264se30_device::vram_r), this), write32_delegate(FUNC(nubus_cb264se30_device::vram_w), this));
-	m_nubus->install_device(slotspace+0xf00000, slotspace+0xfeffff, read32_delegate(FUNC(nubus_cb264se30_device::cb264se30_r), this), write32_delegate(FUNC(nubus_cb264se30_device::cb264se30_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_cb264se30_device::vram_r), this), write32_delegate(FUNC(nubus_cb264se30_device::vram_w), this));
+	nubus().install_device(slotspace+0xf00000, slotspace+0xfeffff, read32_delegate(FUNC(nubus_cb264se30_device::cb264se30_r), this), write32_delegate(FUNC(nubus_cb264se30_device::cb264se30_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(479, 0), 0);
diff --git a/src/devices/bus/nubus/pds30_mc30.cpp b/src/devices/bus/nubus/pds30_mc30.cpp
index 9a04b9aeb60..1456c88770a 100644
--- a/src/devices/bus/nubus/pds30_mc30.cpp
+++ b/src/devices/bus/nubus/pds30_mc30.cpp
@@ -83,8 +83,6 @@ void nubus_xceedmc30_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, XCEEDMC30_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -94,8 +92,8 @@ void nubus_xceedmc30_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_xceedmc30_device::vram_r), this), write32_delegate(FUNC(nubus_xceedmc30_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x800000, slotspace+0xefffff, read32_delegate(FUNC(nubus_xceedmc30_device::xceedmc30_r), this), write32_delegate(FUNC(nubus_xceedmc30_device::xceedmc30_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_xceedmc30_device::vram_r), this), write32_delegate(FUNC(nubus_xceedmc30_device::vram_w), this));
+	nubus().install_device(slotspace+0x800000, slotspace+0xefffff, read32_delegate(FUNC(nubus_xceedmc30_device::xceedmc30_r), this), write32_delegate(FUNC(nubus_xceedmc30_device::xceedmc30_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(479, 0), 0);
diff --git a/src/devices/bus/nubus/pds30_procolor816.cpp b/src/devices/bus/nubus/pds30_procolor816.cpp
index f0c8560bd51..d0d73a81a7e 100644
--- a/src/devices/bus/nubus/pds30_procolor816.cpp
+++ b/src/devices/bus/nubus/pds30_procolor816.cpp
@@ -86,8 +86,6 @@ void nubus_procolor816_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, PROCOLOR816_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -97,9 +95,9 @@ void nubus_procolor816_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_procolor816_device::vram_r), this), write32_delegate(FUNC(nubus_procolor816_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_procolor816_device::vram_r), this), write32_delegate(FUNC(nubus_procolor816_device::vram_w), this));
-	m_nubus->install_device(slotspace+0xf00000, slotspace+0xff7fff, read32_delegate(FUNC(nubus_procolor816_device::procolor816_r), this), write32_delegate(FUNC(nubus_procolor816_device::procolor816_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_procolor816_device::vram_r), this), write32_delegate(FUNC(nubus_procolor816_device::vram_w), this));
+	nubus().install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_procolor816_device::vram_r), this), write32_delegate(FUNC(nubus_procolor816_device::vram_w), this));
+	nubus().install_device(slotspace+0xf00000, slotspace+0xff7fff, read32_delegate(FUNC(nubus_procolor816_device::procolor816_r), this), write32_delegate(FUNC(nubus_procolor816_device::procolor816_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(479, 0), 0);
diff --git a/src/devices/bus/nubus/pds30_sigmalview.cpp b/src/devices/bus/nubus/pds30_sigmalview.cpp
index 38abae63158..0d1daef83ea 100644
--- a/src/devices/bus/nubus/pds30_sigmalview.cpp
+++ b/src/devices/bus/nubus/pds30_sigmalview.cpp
@@ -81,8 +81,6 @@ void nubus_lview_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, LVIEW_ROM_REGION);
 
 	slotspace = get_slotspace();
@@ -92,9 +90,9 @@ void nubus_lview_device::device_start()
 	m_vram.resize(VRAM_SIZE);
 	m_vram32 = (uint32_t *)&m_vram[0];
 
-	m_nubus->install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_lview_device::vram_r), this), write32_delegate(FUNC(nubus_lview_device::vram_w), this));
-	m_nubus->install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_lview_device::vram_r), this), write32_delegate(FUNC(nubus_lview_device::vram_w), this));
-	m_nubus->install_device(slotspace+0xb0000, slotspace+0xbffff, read32_delegate(FUNC(nubus_lview_device::lview_r), this), write32_delegate(FUNC(nubus_lview_device::lview_w), this));
+	nubus().install_device(slotspace, slotspace+VRAM_SIZE-1, read32_delegate(FUNC(nubus_lview_device::vram_r), this), write32_delegate(FUNC(nubus_lview_device::vram_w), this));
+	nubus().install_device(slotspace+0x900000, slotspace+VRAM_SIZE-1+0x900000, read32_delegate(FUNC(nubus_lview_device::vram_r), this), write32_delegate(FUNC(nubus_lview_device::vram_w), this));
+	nubus().install_device(slotspace+0xb0000, slotspace+0xbffff, read32_delegate(FUNC(nubus_lview_device::lview_r), this), write32_delegate(FUNC(nubus_lview_device::lview_w), this));
 
 	m_timer = timer_alloc(0, nullptr);
 	m_timer->adjust(screen().time_until_pos(599, 0), 0);
diff --git a/src/devices/bus/nubus/quadralink.cpp b/src/devices/bus/nubus/quadralink.cpp
index 9b8abc93c91..e8375b181e8 100644
--- a/src/devices/bus/nubus/quadralink.cpp
+++ b/src/devices/bus/nubus/quadralink.cpp
@@ -104,13 +104,11 @@ void nubus_quadralink_device::device_start()
 {
 	uint32_t slotspace;
 
-	// set_nubus_device makes m_slot valid
-	set_nubus_device();
 	install_declaration_rom(this, QUADRALINK_ROM_REGION);
 
 	slotspace = get_slotspace();
 
-	m_nubus->install_device(slotspace, slotspace+0xefffff, read32_delegate(FUNC(nubus_quadralink_device::dev_r), this), write32_delegate(FUNC(nubus_quadralink_device::dev_w), this));
+	nubus().install_device(slotspace, slotspace+0xefffff, read32_delegate(FUNC(nubus_quadralink_device::dev_r), this), write32_delegate(FUNC(nubus_quadralink_device::dev_w), this));
 }
 
 //-------------------------------------------------