diff --git a/src/mame/mame.lst b/src/mame/mame.lst
index 227bf501146..aa15459139b 100644
--- a/src/mame/mame.lst
+++ b/src/mame/mame.lst
@@ -39095,9 +39095,11 @@ psionla
 psionlam
 psionlz
 psionlz64
-psionlz64s
 psionp200
+psionp200a
+psionp250
 psionp350
+psionp432
 psionp464
 psionxp
 
diff --git a/src/mame/psion/psion.cpp b/src/mame/psion/psion.cpp
index 3c9f6c1b78a..043161f5eee 100644
--- a/src/mame/psion/psion.cpp
+++ b/src/mame/psion/psion.cpp
@@ -4,11 +4,9 @@
 
         Psion Organiser II series
 
-        Driver by Sandro Ronco
-
         TODO:
         - dump CGROM of the HD44780
-        - emulate other devices in slot C(Comms Link, printer)
+        - emulate other devices in slot C (Comms Link, Printer, etc.)
 
         Note:
         - 4 lines display has an custom LCD controller derived from an HD66780
@@ -22,16 +20,151 @@
 
 
 #include "emu.h"
-#include "psion.h"
 
+#include "psion_pack.h"
+#include "cpu/m6800/m6801.h"
+#include "machine/nvram.h"
+#include "machine/ram.h"
+#include "machine/timer.h"
+#include "video/hd44780.h"
+#include "sound/beep.h"
+
+#include "emupal.h"
 #include "screen.h"
 #include "softlist_dev.h"
 #include "speaker.h"
 
 
+namespace {
+
+class psion_state : public driver_device
+{
+public:
+	psion_state(const machine_config &mconfig, device_type type, const char *tag)
+		: driver_device(mconfig, type, tag)
+		, m_maincpu(*this, "maincpu")
+		, m_lcdc(*this, "hd44780")
+		, m_screen(*this, "screen")
+		, m_beep(*this, "beeper")
+		, m_pack(*this, "pack%u", 1U)
+		, m_topslot(*this, "topslot")
+		, m_nvram(*this, "nvram")
+		, m_ram(*this, "ram")
+		, m_kb_lines(*this, "K%u", 1U)
+		, m_kb_on(*this, "ON")
+		, m_battery(*this, "BATTERY")
+	{ }
+
+	void psion_base(machine_config &config);
+
+	DECLARE_INPUT_CHANGED_MEMBER(psion_on);
+
+protected:
+	virtual void machine_start() override ATTR_COLD;
+	virtual void machine_reset() override ATTR_COLD;
+
+	required_device<hd6301x_cpu_device> m_maincpu;
+	required_device<hd44780_device> m_lcdc;
+	required_device<screen_device> m_screen;
+	required_device<beep_device> m_beep;
+	required_device_array<datapack_device, 2> m_pack;
+	optional_device<datapack_device> m_topslot;
+	required_device<nvram_device> m_nvram;
+	required_device<ram_device> m_ram;
+	required_ioport_array<7> m_kb_lines;
+	required_ioport m_kb_on;
+	required_ioport m_battery;
+
+	uint8_t kb_read();
+	void port2_w(offs_t offset, uint8_t data, uint8_t ddr);
+	uint8_t port2_r();
+	uint8_t port5_r();
+	void port6_w(uint8_t data);
+	uint8_t port6_r();
+
+	void psion_palette(palette_device &palette) const;
+	TIMER_DEVICE_CALLBACK_MEMBER(nmi_timer);
+
+	uint16_t m_kb_counter = 0;
+	bool m_nmi_enable = false;
+	uint8_t m_pulse_enable = 0;
+};
+
+
+class psion1_state : public psion_state
+{
+public:
+	psion1_state(const machine_config &mconfig, device_type type, const char *tag)
+		: psion_state(mconfig, type, tag)
+	{ }
+
+	void psion1(machine_config &config);
+
+protected:
+	virtual void machine_reset() override ATTR_COLD;
+
+private:
+	HD44780_PIXEL_UPDATE(psion1_pixel_update);
+
+	void psion1_mem(address_map &map) ATTR_COLD;
+
+	uint8_t reset_kb_counter_r();
+	uint8_t inc_kb_counter_r();
+	uint8_t switchoff_r();
+};
+
+
+class psion2_state : public psion_state
+{
+public:
+	psion2_state(const machine_config &mconfig, device_type type, const char *tag)
+		: psion_state(mconfig, type, tag)
+		, m_rambank1(*this, "rambank1")
+		, m_rambank2(*this, "rambank2")
+		, m_rombank1(*this, "rombank1")
+		, m_rombank2(*this, "rombank2")
+	{ }
+
+	void psion2(machine_config &config);
+	void psioncm(machine_config &config);
+	void psionxp(machine_config &config);
+	void psionla(machine_config &config);
+	void psionlz(machine_config &config);
+	void psionlz64(machine_config &config);
+	void psionp200(machine_config &config);
+	void psionp350(machine_config &config);
+	void psionp432(machine_config &config);
+	void psionp464(machine_config &config);
+
+protected:
+	virtual void machine_start() override ATTR_COLD;
+	virtual void machine_reset() override ATTR_COLD;
+
+private:
+	required_memory_bank m_rambank1;
+	optional_memory_bank m_rambank2;
+	required_memory_bank m_rombank1;
+	optional_memory_bank m_rombank2;
+
+	HD44780_PIXEL_UPDATE(lz_pixel_update);
+
+	void io_rw(uint16_t offset);
+	void io_w(offs_t offset, uint8_t data);
+	uint8_t io_r(offs_t offset);
+
+	void psioncm_mem(address_map &map) ATTR_COLD;
+	void psionxp_mem(address_map &map) ATTR_COLD;
+	void psionla_mem(address_map &map) ATTR_COLD;
+
+	// RAM/ROM banks
+	uint8_t m_rambank_count = 0;
+	uint8_t m_rombank_count = 0;
+};
+
+
 TIMER_DEVICE_CALLBACK_MEMBER(psion_state::nmi_timer)
 {
-	if (m_enable_nmi)
+	if (m_nmi_enable)
 		m_maincpu->pulse_input_line(INPUT_LINE_NMI, attotime::zero);
 }
 
@@ -55,26 +188,26 @@ uint8_t psion_state::kb_read()
 	return data & 0x7c;
 }
 
-void psion_state::update_banks()
-{
-	if (m_ram_bank < m_ram_bank_count && m_ram_bank_count)
-		membank("rambank")->set_entry(m_ram_bank);
-
-	if (m_rom_bank < m_rom_bank_count && m_rom_bank_count)
-		membank("rombank")->set_entry(m_rom_bank);
-}
 
 void psion_state::port2_w(offs_t offset, uint8_t data, uint8_t ddr)
 {
 	/* datapack i/o data bus */
-	m_pack1->data_w(data & ddr);
-	m_pack2->data_w(data & ddr);
+	m_pack[0]->data_w(data & ddr);
+	m_pack[1]->data_w(data & ddr);
+
+	if (m_topslot)
+		m_topslot->data_w(data & ddr);
 }
 
 uint8_t psion_state::port2_r()
 {
 	/* datapack i/o data bus */
-	return m_pack1->data_r() | m_pack2->data_r();
+	uint8_t data = m_pack[0]->data_r() | m_pack[1]->data_r();
+
+	if (m_topslot)
+		data |= m_topslot->data_r();
+
+	return data;
 }
 
 uint8_t psion_state::port5_r()
@@ -85,7 +218,7 @@ uint8_t psion_state::port5_r()
 	---- --x- pulse
 	---- ---x battery status
 	*/
-	return kb_read() | ioport("BATTERY")->read() | ioport("ON")->read() | (m_kb_counter == 0x7ff)<<1 | m_pulse<<1;
+	return kb_read() | m_battery->read() | m_kb_on->read() | (m_kb_counter == 0x7ff)<<1 | m_pulse_enable<<1;
 }
 
 void psion_state::port6_w(uint8_t data)
@@ -101,18 +234,26 @@ void psion_state::port6_w(uint8_t data)
 	---- --x- reset line
 	---- ---x clock line
 	*/
-	m_pack1->control_w((data & 0x8f) | (data & 0x10));
-	m_pack2->control_w((data & 0x8f) | ((data & 0x20) >> 1));
+	m_pack[0]->control_w((data & 0x8f) | (data & 0x10));
+	m_pack[1]->control_w((data & 0x8f) | ((data & 0x20) >> 1));
+
+	if (m_topslot)
+		m_topslot->control_w((data & 0x8f) | ((data & 0x40) >> 2));
 }
 
 uint8_t psion_state::port6_r()
 {
 	/* datapack control lines */
-	return (m_pack1->control_r() | (m_pack2->control_r() & 0x8f)) | ((m_pack2->control_r() & 0x10)<<1);
+	uint8_t data = (m_pack[0]->control_r() | (m_pack[1]->control_r() & 0x8f)) | ((m_pack[1]->control_r() & 0x10) << 1);
+
+	if (m_topslot)
+		data |= (m_topslot->control_r() & 0x8f) | ((m_topslot->control_r() & 0x10) << 2);
+
+	return data;
 }
 
 /* Read/Write common */
-void psion_state::io_rw(uint16_t offset)
+void psion2_state::io_rw(uint16_t offset)
 {
 	if (machine().side_effects_disabled())
 		return;
@@ -121,17 +262,14 @@ void psion_state::io_rw(uint16_t offset)
 	{
 	case 0xc0:
 		/* switch off, CPU goes into standby mode */
-		m_enable_nmi = false;
+		m_nmi_enable = false;
 		m_maincpu->set_input_line(M6801_STBY_LINE, ASSERT_LINE);
 		break;
 	case 0x100:
-		m_pulse = 1;
+		m_pulse_enable = 1;
 		break;
 	case 0x140:
-		m_pulse = 0;
-		break;
-	case 0x200:
-		m_kb_counter = 0;
+		m_pulse_enable = 0;
 		break;
 	case 0x180:
 		m_beep->set_state(1);
@@ -139,40 +277,53 @@ void psion_state::io_rw(uint16_t offset)
 	case 0x1c0:
 		m_beep->set_state(0);
 		break;
+	case 0x200:
+		m_kb_counter = 0;
+		break;
 	case 0x240:
-		if (offset == 0x260 && (m_rom_bank_count || m_ram_bank_count))
+		if (offset == 0x260 && (m_rombank_count || m_rambank_count))
 		{
-			m_ram_bank=0;
-			m_rom_bank=0;
-			update_banks();
+			if (m_rambank_count)
+				m_rambank2->set_entry(0);
+
+			if (m_rombank_count)
+				m_rombank2->set_entry(0);
 		}
 		else
+		{
 			m_kb_counter++;
+		}
 		break;
 	case 0x280:
-		if (offset == 0x2a0 && m_ram_bank_count)
+		if (offset == 0x2a0 && m_rambank_count)
 		{
-			m_ram_bank++;
-			update_banks();
+			int const rambank = m_rambank2->entry() + 1;
+			if (rambank < m_rambank_count)
+				m_rambank2->set_entry(rambank);
 		}
 		else
-			m_enable_nmi = true;
+		{
+			m_nmi_enable = true;
+		}
 		break;
 	case 0x2c0:
-		if (offset == 0x2e0 && m_rom_bank_count)
+		if (offset == 0x2e0 && m_rombank_count)
 		{
-			m_rom_bank++;
-			update_banks();
+			int const rombank = m_rombank2->entry() + 1;
+			if (rombank < m_rombank_count)
+				m_rombank2->set_entry(rombank);
 		}
 		else
-			m_enable_nmi = false;
+		{
+			m_nmi_enable = false;
+		}
 		break;
 	}
 }
 
-void psion_state::io_w(offs_t offset, uint8_t data)
+void psion2_state::io_w(offs_t offset, uint8_t data)
 {
-	switch (offset & 0x0ffc0)
+	switch (offset & 0xffc0)
 	{
 	case 0x80:
 		m_lcdc->write(offset & 0x01, data);
@@ -183,15 +334,14 @@ void psion_state::io_w(offs_t offset, uint8_t data)
 	}
 }
 
-uint8_t psion_state::io_r(offs_t offset)
+uint8_t psion2_state::io_r(offs_t offset)
 {
 	switch (offset & 0xffc0)
 	{
 	case 0x80:
 		return m_lcdc->read(offset & 0x01);
 	default:
-		if (!machine().side_effects_disabled())
-			io_rw(offset);
+		io_rw(offset);
 		break;
 	}
 
@@ -241,69 +391,112 @@ void psion1_state::psion1_mem(address_map &map)
 	map(0x4000, 0x47ff).ram().share("ram");
 }
 
-void psion_state::psioncm_mem(address_map &map)
+void psion2_state::psioncm_mem(address_map &map)
 {
 	map.unmap_value_low();
-	map(0x0100, 0x03ff).rw(FUNC(psion_state::io_r), FUNC(psion_state::io_w));
-	map(0x2000, 0x3fff).ram().share("ram");
-	map(0x8000, 0xffff).rom();
+	map(0x0100, 0x03ff).rw(FUNC(psion2_state::io_r), FUNC(psion2_state::io_w));
+	map(0x2000, 0x3fff).bankrw("rambank1");
+	map(0x8000, 0xbfff).bankr("rombank2");
+	map(0xc000, 0xffff).bankr("rombank1");
 }
 
-void psion_state::psionla_mem(address_map &map)
+void psion2_state::psionxp_mem(address_map &map)
 {
 	map.unmap_value_low();
-	map(0x0100, 0x03ff).rw(FUNC(psion_state::io_r), FUNC(psion_state::io_w));
-	map(0x0400, 0x5fff).ram().share("ram");
-	map(0x8000, 0xffff).rom();
+	map(0x0100, 0x03ff).rw(FUNC(psion2_state::io_r), FUNC(psion2_state::io_w));
+	map(0x2000, 0x5fff).bankrw("rambank1");
+	map(0x8000, 0xbfff).bankr("rombank2");
+	map(0xc000, 0xffff).bankr("rombank1");
 }
 
-void psion_state::psionp350_mem(address_map &map)
+void psion2_state::psionla_mem(address_map &map)
 {
 	map.unmap_value_low();
-	map(0x0100, 0x03ff).rw(FUNC(psion_state::io_r), FUNC(psion_state::io_w));
-	map(0x0400, 0x3fff).ram().share("ram");
-	map(0x4000, 0x7fff).bankrw("rambank");
-	map(0x8000, 0xffff).rom();
+	map(0x0100, 0x03ff).rw(FUNC(psion2_state::io_r), FUNC(psion2_state::io_w));
+	map(0x0400, 0x3fff).bankrw("rambank1");
+	map(0x4000, 0x7fff).bankrw("rambank2");
+	map(0x8000, 0xbfff).bankr("rombank2");
+	map(0xc000, 0xffff).bankr("rombank1");
 }
 
-void psion_state::psionlam_mem(address_map &map)
-{
-	map.unmap_value_low();
-	map(0x0100, 0x03ff).rw(FUNC(psion_state::io_r), FUNC(psion_state::io_w));
-	map(0x0400, 0x7fff).ram().share("ram");
-	map(0x8000, 0xbfff).bankr("rombank");
-	map(0xc000, 0xffff).rom();
-}
-
-void psion_state::psionlz_mem(address_map &map)
-{
-	map.unmap_value_low();
-	map(0x0100, 0x03ff).rw(FUNC(psion_state::io_r), FUNC(psion_state::io_w));
-	map(0x0400, 0x3fff).ram().share("ram");
-	map(0x4000, 0x7fff).bankrw("rambank");
-	map(0x8000, 0xbfff).bankr("rombank");
-	map(0xc000, 0xffff).rom();
-}
 
 /* Input ports */
 INPUT_PORTS_START( psion )
 	PORT_START("BATTERY")
-		PORT_CONFNAME( 0x01, 0x00, "Battery Status" )
-		PORT_CONFSETTING( 0x00, DEF_STR( Normal ) )
-		PORT_CONFSETTING( 0x01, "Low Battery" )
+	PORT_CONFNAME( 0x01, 0x00, "Battery Status" )
+	PORT_CONFSETTING( 0x00, DEF_STR( Normal ) )
+	PORT_CONFSETTING( 0x01, "Low Battery" )
 
 	PORT_START("ON")
-		PORT_BIT(0x80, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("ON/CLEAR") PORT_CODE(KEYCODE_MINUS)  PORT_CHANGED_MEMBER(DEVICE_SELF, FUNC(psion_state::psion_on), 0)
+	PORT_BIT(0x80, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("ON/CLEAR") PORT_CODE(KEYCODE_ESC)  PORT_CHANGED_MEMBER(DEVICE_SELF, FUNC(psion_state::psion_on), 0)
+INPUT_PORTS_END
+
+INPUT_PORTS_START( psion1 )
+	PORT_INCLUDE(psion)
 
 	PORT_START("K1")
-		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("MODE") PORT_CODE(KEYCODE_EQUALS)
-		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Up [CAP]") PORT_CODE(KEYCODE_UP)
-		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Down [NUM]") PORT_CODE(KEYCODE_DOWN)
-		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Left") PORT_CODE(KEYCODE_LEFT)
-		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("RIGHT") PORT_CODE(KEYCODE_RIGHT)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2192 [>>]") PORT_CODE(KEYCODE_RIGHT)  // U+2192 = →
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2190 [<<]") PORT_CODE(KEYCODE_LEFT)   // U+2190 = ←
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2193 [FIND]") PORT_CODE(KEYCODE_DOWN) // U+2193 = ↓
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2191 [SAVE]") PORT_CODE(KEYCODE_UP)   // U+2191 = ↑
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("MODE/HOME") PORT_CODE(KEYCODE_EQUALS)
 
 	PORT_START("K2")
-		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Shift") PORT_CODE(KEYCODE_LSHIFT)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SHIFT") PORT_CODE(KEYCODE_LSHIFT)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("S [,]") PORT_CODE(KEYCODE_S)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("M [%]") PORT_CODE(KEYCODE_M)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("G [=]") PORT_CODE(KEYCODE_G)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("A [<]") PORT_CODE(KEYCODE_A)
+
+	PORT_START("K3")
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Y [(]") PORT_CODE(KEYCODE_Y)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("T [:]") PORT_CODE(KEYCODE_T)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("N [$]") PORT_CODE(KEYCODE_N)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("H [\"]") PORT_CODE(KEYCODE_H)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("B [>]") PORT_CODE(KEYCODE_B)
+
+	PORT_START("K4")
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Z [)]") PORT_CODE(KEYCODE_Z)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("U [0]") PORT_CODE(KEYCODE_U)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("O [1]") PORT_CODE(KEYCODE_O)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("I [4]") PORT_CODE(KEYCODE_I)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("C [7]") PORT_CODE(KEYCODE_C)
+
+	PORT_START("K5")
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("DELETE") PORT_CODE(KEYCODE_DEL)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("W [EE]") PORT_CODE(KEYCODE_W)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Q [3]") PORT_CODE(KEYCODE_Q)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("K [6]") PORT_CODE(KEYCODE_K)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("E [9]") PORT_CODE(KEYCODE_E)
+
+	PORT_START("K6")
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("EXECUTE") PORT_CODE(KEYCODE_ENTER)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("X [+]") PORT_CODE(KEYCODE_X)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("R [-]") PORT_CODE(KEYCODE_R)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("L [*]") PORT_CODE(KEYCODE_L)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F [/]") PORT_CODE(KEYCODE_F)
+
+	PORT_START("K7")
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SPACE") PORT_CODE(KEYCODE_SPACE)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("V [.]") PORT_CODE(KEYCODE_V)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("P [2]") PORT_CODE(KEYCODE_P)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("J [5]") PORT_CODE(KEYCODE_J)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("D [8]") PORT_CODE(KEYCODE_D)
+INPUT_PORTS_END
+
+INPUT_PORTS_START( psion2 )
+	PORT_INCLUDE(psion)
+
+	// Normal keyboard
+	PORT_START("K1")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("MODE") PORT_CODE(KEYCODE_EQUALS)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2191 [CAP]") PORT_CODE(KEYCODE_UP)   // U+2191 = ↑
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2193 [NUM]") PORT_CODE(KEYCODE_DOWN) // U+2193 = ↓
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2190") PORT_CODE(KEYCODE_LEFT)       // U+2190 = ←
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2192") PORT_CODE(KEYCODE_RIGHT)      // U+2192 = →
+
+	PORT_START("K2")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SHIFT") PORT_CODE(KEYCODE_LSHIFT)
 		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("S [;]") PORT_CODE(KEYCODE_S)
 		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("M [,]") PORT_CODE(KEYCODE_M)
 		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("G [=]") PORT_CODE(KEYCODE_G)
@@ -324,7 +517,7 @@ INPUT_PORTS_START( psion )
 		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("C [(]") PORT_CODE(KEYCODE_C)
 
 	PORT_START("K5")
-		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Space") PORT_CODE(KEYCODE_SPACE)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SPACE") PORT_CODE(KEYCODE_SPACE)
 		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("W [3]") PORT_CODE(KEYCODE_W)
 		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Q [6]") PORT_CODE(KEYCODE_Q)
 		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("K [9]") PORT_CODE(KEYCODE_K)
@@ -345,142 +538,199 @@ INPUT_PORTS_START( psion )
 		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("D [)]") PORT_CODE(KEYCODE_D)
 INPUT_PORTS_END
 
-INPUT_PORTS_START( psion1 )
-	PORT_START("BATTERY")
-	PORT_CONFNAME( 0x01, 0x00, "Battery Status" )
-	PORT_CONFSETTING( 0x00, DEF_STR( Normal ) )
-	PORT_CONFSETTING( 0x01, "Low Battery" )
-
-	PORT_START("ON")
-	PORT_BIT(0x80, IP_ACTIVE_HIGH, IPT_KEYBOARD) PORT_NAME("ON/CLEAR") PORT_CODE(KEYCODE_MINUS)  PORT_CHANGED_MEMBER(DEVICE_SELF, FUNC(psion_state::psion_on), 0)
+INPUT_PORTS_START( psion2a )
+	PORT_INCLUDE(psion)
 
+	// Alpha keyboard
 	PORT_START("K1")
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("RIGHT") PORT_CODE(KEYCODE_RIGHT)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Left") PORT_CODE(KEYCODE_LEFT)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Down [NUM]") PORT_CODE(KEYCODE_DOWN)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Up [CAP]") PORT_CODE(KEYCODE_UP)
-	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("MODE") PORT_CODE(KEYCODE_EQUALS)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("MODE") PORT_CODE(KEYCODE_EQUALS)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2191") PORT_CODE(KEYCODE_UP)    // U+2191 = ↑
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2193") PORT_CODE(KEYCODE_DOWN)  // U+2193 = ↓
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2190") PORT_CODE(KEYCODE_LEFT)  // U+2190 = ←
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(u8"\u2192") PORT_CODE(KEYCODE_RIGHT) // U+2192 = →
 
 	PORT_START("K2")
-	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Shift") PORT_CODE(KEYCODE_LSHIFT)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("S [;]") PORT_CODE(KEYCODE_S)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("M [,]") PORT_CODE(KEYCODE_M)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("G [=]") PORT_CODE(KEYCODE_G)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("A [<]") PORT_CODE(KEYCODE_A)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Shift") PORT_CODE(KEYCODE_LSHIFT)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("S") PORT_CODE(KEYCODE_S)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("M") PORT_CODE(KEYCODE_M)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("G") PORT_CODE(KEYCODE_G)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("A") PORT_CODE(KEYCODE_A)
 
 	PORT_START("K3")
-	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Y [0]") PORT_CODE(KEYCODE_Y)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("T [:]") PORT_CODE(KEYCODE_T)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("N [$]") PORT_CODE(KEYCODE_N)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("H [\"]") PORT_CODE(KEYCODE_H)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("B [>]") PORT_CODE(KEYCODE_B)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("DEL") PORT_CODE(KEYCODE_DEL)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("T") PORT_CODE(KEYCODE_T)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("No [N]") PORT_CODE(KEYCODE_N)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("H") PORT_CODE(KEYCODE_H)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("B") PORT_CODE(KEYCODE_B)
 
 	PORT_START("K4")
-	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Z [.]") PORT_CODE(KEYCODE_Z)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("U [1]") PORT_CODE(KEYCODE_U)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("O [4]") PORT_CODE(KEYCODE_O)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("I [7]") PORT_CODE(KEYCODE_I)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("C [(]") PORT_CODE(KEYCODE_C)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("YES [Y]") PORT_CODE(KEYCODE_Y)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("U") PORT_CODE(KEYCODE_U)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("O") PORT_CODE(KEYCODE_O)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("I") PORT_CODE(KEYCODE_I)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("C") PORT_CODE(KEYCODE_C)
 
 	PORT_START("K5")
-	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("DEL") PORT_CODE(KEYCODE_DEL)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("W [3]") PORT_CODE(KEYCODE_W)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Q [6]") PORT_CODE(KEYCODE_Q)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("K [9]") PORT_CODE(KEYCODE_K)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("E [%]") PORT_CODE(KEYCODE_E)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("SPACE") PORT_CODE(KEYCODE_SPACE)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(". [W]") PORT_CODE(KEYCODE_W)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("2 [Q]") PORT_CODE(KEYCODE_Q)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("5 [K]") PORT_CODE(KEYCODE_K)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("8 [E]") PORT_CODE(KEYCODE_E)
 
 	PORT_START("K6")
-	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("EXE") PORT_CODE(KEYCODE_ENTER)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("X [+]") PORT_CODE(KEYCODE_X)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("R [-]") PORT_CODE(KEYCODE_R)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("L [*]") PORT_CODE(KEYCODE_L)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F [/]") PORT_CODE(KEYCODE_F)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("ENTER") PORT_CODE(KEYCODE_ENTER)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("- [X]") PORT_CODE(KEYCODE_X)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("3 [R]") PORT_CODE(KEYCODE_R)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("6 [L]") PORT_CODE(KEYCODE_L)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("9 [F]") PORT_CODE(KEYCODE_F)
 
 	PORT_START("K7")
-	PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Space") PORT_CODE(KEYCODE_SPACE)
-	PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("V [2]") PORT_CODE(KEYCODE_V)
-	PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("P [5]") PORT_CODE(KEYCODE_P)
-	PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("J [8]") PORT_CODE(KEYCODE_J)
-	PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("D [)]") PORT_CODE(KEYCODE_D)
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("Z") PORT_CODE(KEYCODE_Z)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("0 [V]") PORT_CODE(KEYCODE_V)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("1 [P]") PORT_CODE(KEYCODE_P)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("4 [J]") PORT_CODE(KEYCODE_J)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("7 [D]") PORT_CODE(KEYCODE_D)
+INPUT_PORTS_END
+
+INPUT_PORTS_START( psion2n )
+	PORT_INCLUDE(psion)
+
+	// Numerical keyboard
+	PORT_START("K1")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("7") PORT_CODE(KEYCODE_7)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("8") PORT_CODE(KEYCODE_8)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("9") PORT_CODE(KEYCODE_9)
+
+	PORT_START("K2")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("EXE") PORT_CODE(KEYCODE_ENTER)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F3") PORT_CODE(KEYCODE_F3)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F2") PORT_CODE(KEYCODE_F2)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("F1") PORT_CODE(KEYCODE_F1)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("MODE") PORT_CODE(KEYCODE_EQUALS)
+
+	PORT_START("K3")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("1") PORT_CODE(KEYCODE_1)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("4") PORT_CODE(KEYCODE_4)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("K4")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("0") PORT_CODE(KEYCODE_0)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("K5")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME(".") PORT_CODE(KEYCODE_STOP)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("K6")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("3") PORT_CODE(KEYCODE_3)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("6") PORT_CODE(KEYCODE_6)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_UNUSED)
+
+	PORT_START("K7")
+		PORT_BIT(0x04, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x08, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("2") PORT_CODE(KEYCODE_2)
+		PORT_BIT(0x10, IP_ACTIVE_LOW, IPT_UNUSED)
+		PORT_BIT(0x20, IP_ACTIVE_LOW, IPT_KEYBOARD) PORT_NAME("5") PORT_CODE(KEYCODE_5)
+		PORT_BIT(0x40, IP_ACTIVE_LOW, IPT_UNUSED)
 INPUT_PORTS_END
 
 
 void psion_state::machine_start()
 {
-	if (!strcmp(machine().system().name, "psionlam"))
-	{
-		m_rom_bank_count = 3;
-		m_ram_bank_count = 0;
-	}
-	else if (!strncmp(machine().system().name, "psionlz", 7))
-	{
-		m_rom_bank_count = 3;
-		m_ram_bank_count = 3;
-	}
-	else if (!strcmp(machine().system().name, "psionp464"))
-	{
-		m_rom_bank_count = 3;
-		m_ram_bank_count = 9;
-	}
-	else if (!strncmp(machine().system().name, "psionp", 6))
-	{
-		m_rom_bank_count = 0;
-		m_ram_bank_count = 5;
-	}
-	else
-	{
-		m_rom_bank_count = 0;
-		m_ram_bank_count = 0;
-	}
-
-	if (m_rom_bank_count)
-	{
-		uint8_t* rom_base = (uint8_t *)memregion("maincpu")->base();
-
-		membank("rombank")->configure_entry(0, rom_base + 0x8000);
-		membank("rombank")->configure_entries(1, m_rom_bank_count-1, rom_base + 0x10000, 0x4000);
-		membank("rombank")->set_entry(0);
-	}
-
-	if (m_ram_bank_count)
-	{
-		m_paged_ram = std::make_unique<uint8_t[]>(m_ram_bank_count * 0x4000);
-		memset(m_paged_ram.get(), 0, sizeof(uint8_t) * (m_ram_bank_count * 0x4000));
-		membank("rambank")->configure_entries(0, m_ram_bank_count, m_paged_ram.get(), 0x4000);
-		membank("rambank")->set_entry(0);
-	}
-
-	m_nvram1->set_base(m_ram, m_ram.bytes());
-	if (m_nvram2)
-		m_nvram2->set_base(m_paged_ram.get(), m_ram_bank_count * 0x4000);
+	m_nvram->set_base(m_ram->pointer(), m_ram->size());
 
 	save_item(NAME(m_kb_counter));
-	save_item(NAME(m_enable_nmi));
-	save_item(NAME(m_pulse));
-	save_item(NAME(m_rom_bank));
-	save_item(NAME(m_ram_bank));
-	save_pointer(NAME(m_paged_ram), m_ram_bank_count * 0x4000);
+	save_item(NAME(m_nmi_enable));
+	save_item(NAME(m_pulse_enable));
+}
+
+void psion2_state::machine_start()
+{
+	psion_state::machine_start();
+
+	uint8_t *rom_base = memregion("maincpu")->base();
+	uint32_t rom_size = memregion("maincpu")->bytes();
+
+	m_rombank_count = 0;
+	switch (rom_size)
+	{
+	case 0x8000: // 32K
+		m_rombank1->set_base(rom_base + 0x4000);
+		m_rombank2->set_base(rom_base);
+		break;
+
+	default: // >= 64K
+		m_rombank_count = (rom_size - 0x4000) / 0x4000;
+
+		m_rombank1->set_base(rom_base + 0x4000);
+		m_rombank2->configure_entry(0, rom_base);
+		m_rombank2->configure_entries(1, m_rombank_count-1, rom_base + 0x8000, 0x4000);
+		m_rombank2->set_entry(0);
+		break;
+	}
+
+	m_rambank_count = 0;
+	switch (m_ram->size())
+	{
+	case 0x2000: // 8K
+	case 0x4000: // 16K
+		m_rambank1->set_base(m_ram->pointer());
+		break;
+
+	case 0x8000: // 32K
+		m_rambank1->set_base(m_ram->pointer() + 0x0400);
+		m_rambank2->set_base(m_ram->pointer() + 0x4000);
+		break;
+
+	default: // >= 64K
+		m_rambank_count = (m_ram->size() - 0x4000) / 0x4000;
+
+		m_rambank1->set_base(m_ram->pointer() + 0x0400);
+		m_rambank2->configure_entries(0, m_rambank_count, m_ram->pointer() + 0x4000, 0x4000);
+		m_rambank2->set_entry(0);
+		break;
+	}
 }
 
 void psion_state::machine_reset()
 {
-	m_enable_nmi = false;
+	m_nmi_enable = false;
 	m_kb_counter = 0;
-	m_ram_bank = 0;
-	m_rom_bank = 0;
-	m_pulse = 0;
-
-	if (m_rom_bank_count || m_ram_bank_count)
-		update_banks();
+	m_pulse_enable = 0;
 }
 
 void psion1_state::machine_reset()
 {
 	psion_state::machine_reset();
-	m_enable_nmi = true;
+
+	m_nmi_enable = true;
 }
 
-HD44780_PIXEL_UPDATE(psion_state::lz_pixel_update)
+void psion2_state::machine_reset()
+{
+	psion_state::machine_reset();
+
+	if (m_rambank_count)
+		m_rambank2->set_entry(0);
+
+	if (m_rombank_count)
+		m_rombank2->set_entry(0);
+}
+
+
+HD44780_PIXEL_UPDATE(psion2_state::lz_pixel_update)
 {
 	if (pos < 40)
 	{
@@ -524,67 +774,37 @@ static GFXDECODE_START( gfx_psion )
 	GFXDECODE_ENTRY( "hd44780:cgrom", 0x0000, psion_charlayout, 0, 1 )
 GFXDECODE_END
 
-/* basic configuration for 2 lines display */
-void psion_state::psion_2lines(machine_config &config)
-{
-	/* basic machine hardware */
-	HD6303X(config, m_maincpu, 3.6864_MHz_XTAL); // internal operating frequency is 0.9216 MHz
-	m_maincpu->nvram_enable_backup(true);
-	m_maincpu->in_p2_cb().set(FUNC(psion_state::port2_r));
-	m_maincpu->out_p2_cb().set(FUNC(psion_state::port2_w));
-	m_maincpu->in_p5_cb().set(FUNC(psion_state::port5_r));
-	m_maincpu->in_p6_cb().set(FUNC(psion_state::port6_r));
-	m_maincpu->out_p6_cb().set(FUNC(psion_state::port6_w));
 
+void psion_state::psion_base(machine_config &config)
+{
 	/* video hardware */
-	screen_device &screen(SCREEN(config, "screen", SCREEN_TYPE_LCD));
-	screen.set_refresh_hz(50);
-	screen.set_vblank_time(ATTOSECONDS_IN_USEC(2500)); /* not accurate */
-	screen.set_screen_update("hd44780", FUNC(hd44780_device::screen_update));
-	screen.set_size(6*16, 9*2);
-	screen.set_visarea_full();
-	screen.set_palette("palette");
+	SCREEN(config, m_screen, SCREEN_TYPE_LCD);
+	m_screen->set_refresh_hz(50);
+	m_screen->set_vblank_time(ATTOSECONDS_IN_USEC(2500)); /* not accurate */
+	m_screen->set_screen_update("hd44780", FUNC(hd44780_device::screen_update));
+	m_screen->set_palette("palette");
 
 	PALETTE(config, "palette", FUNC(psion_state::psion_palette), 2);
 	GFXDECODE(config, "gfxdecode", "palette", gfx_psion);
 
-	HD44780(config, m_lcdc, 270'000); // TODO: Wrong device? Custom? clock not measured, datasheet typical clock used
-	m_lcdc->set_lcd_size(2, 16);
+	HD44780(config, m_lcdc, 270'000); // TODO: clock not measured, datasheet typical clock used
 
 	/* sound hardware */
 	SPEAKER(config, "mono").front_center();
 	BEEP(config, m_beep, 3250).add_route(ALL_OUTPUTS, "mono", 1.00);
 
-	NVRAM(config, "nvram1", nvram_device::DEFAULT_ALL_0); // RAM
-
-	TIMER(config, "nmi_timer").configure_periodic(FUNC(psion_state::nmi_timer), attotime::from_seconds(1));
+	NVRAM(config, "nvram", nvram_device::DEFAULT_ALL_0); // RAM
 
 	/* Datapack */
-	PSION_DATAPACK(config, m_pack1, 0);
-	PSION_DATAPACK(config, m_pack2, 0);
-
-	/* Software lists */
-	SOFTWARE_LIST(config, "pack_list").set_original("psion2");
-}
-
-/* basic configuration for 4 lines display */
-void psion_state::psion_4lines(machine_config &config)
-{
-	psion_2lines(config);
-
-	/* video hardware */
-	subdevice<screen_device>("screen")->set_size(6*20, 9*4);
-	subdevice<screen_device>("screen")->set_visarea_full();
-
-	m_lcdc->set_lcd_size(4, 20);
-	m_lcdc->set_pixel_update_cb(FUNC(psion_state::lz_pixel_update));
+	PSION_DATAPACK(config, m_pack[0]).set_interface("psion_pack");
+	PSION_DATAPACK(config, m_pack[1]).set_interface("psion_pack");
 }
 
 void psion1_state::psion1(machine_config &config)
 {
-	psion_2lines(config);
+	psion_base(config);
 
-	HD6301X0(config.replace(), m_maincpu, 3.6864_MHz_XTAL);
+	HD6301X0(config, m_maincpu, 3.6864_MHz_XTAL);
 	m_maincpu->set_addrmap(AS_PROGRAM, &psion1_state::psion1_mem);
 	m_maincpu->nvram_enable_backup(true);
 	m_maincpu->in_p2_cb().set(FUNC(psion1_state::port2_r));
@@ -593,192 +813,295 @@ void psion1_state::psion1(machine_config &config)
 	m_maincpu->in_p6_cb().set(FUNC(psion1_state::port6_r));
 	m_maincpu->out_p6_cb().set(FUNC(psion1_state::port6_w));
 
-	timer_device &nmi_timer(TIMER(config.replace(), "nmi_timer"));
+	RAM(config, m_ram).set_default_size("2K");
+
+	timer_device &nmi_timer(TIMER(config, "nmi_timer"));
 	nmi_timer.configure_periodic(FUNC(psion1_state::nmi_timer), attotime::from_msec(500));
 	nmi_timer.set_start_delay(attotime::from_seconds(1));
 
-	subdevice<screen_device>("screen")->set_size(6*16, 1*8);
-	subdevice<screen_device>("screen")->set_visarea_full();
+	m_screen->set_size(6*16, 1*8);
+	m_screen->set_visarea_full();
 
 	m_lcdc->set_lcd_size(1, 16);
 	m_lcdc->set_pixel_update_cb(FUNC(psion1_state::psion1_pixel_update));
 
-	/* Software lists */
-	SOFTWARE_LIST(config.replace(), "pack_list").set_original("psion1");
+	SOFTWARE_LIST(config, "pack_list").set_original("psion1");
 }
 
-void psion_state::psioncm(machine_config &config)
+void psion2_state::psion2(machine_config &config)
 {
-	psion_2lines(config);
+	psion_base(config);
 
-	m_maincpu->set_addrmap(AS_PROGRAM, &psion_state::psioncm_mem);
+	HD6303X(config, m_maincpu, 3.6864_MHz_XTAL); // internal operating frequency is 0.9216 MHz
+	m_maincpu->nvram_enable_backup(true);
+	m_maincpu->in_p2_cb().set(FUNC(psion2_state::port2_r));
+	m_maincpu->out_p2_cb().set(FUNC(psion2_state::port2_w));
+	m_maincpu->in_p5_cb().set(FUNC(psion2_state::port5_r));
+	m_maincpu->in_p6_cb().set(FUNC(psion2_state::port6_r));
+	m_maincpu->out_p6_cb().set(FUNC(psion2_state::port6_w));
+
+	RAM(config, m_ram).set_default_size("32K");
+
+	m_screen->set_size(6*16, 9*2);
+	m_screen->set_visarea_full();
+
+	m_lcdc->set_lcd_size(2, 16);
+
+	TIMER(config, "nmi_timer").configure_periodic(FUNC(psion2_state::nmi_timer), attotime::from_seconds(1));
+
+	PSION_DATAPACK(config, m_topslot).set_interface("psion_topslot");
+
+	SOFTWARE_LIST(config, "pack_list").set_original("psion2");
 }
 
-void psion_state::psionla(machine_config &config)
+void psion2_state::psioncm(machine_config &config)
 {
-	psion_2lines(config);
+	psion2(config);
 
-	m_maincpu->set_addrmap(AS_PROGRAM, &psion_state::psionla_mem);
+	m_maincpu->set_addrmap(AS_PROGRAM, &psion2_state::psioncm_mem);
+
+	m_ram->set_default_size("8K");
+
+	subdevice<software_list_device>("pack_list")->set_filter("CM");
 }
 
-void psion_state::psionlam(machine_config &config)
+void psion2_state::psionxp(machine_config &config)
 {
-	psion_2lines(config);
+	psion2(config);
 
-	m_maincpu->set_addrmap(AS_PROGRAM, &psion_state::psionlam_mem);
+	m_maincpu->set_addrmap(AS_PROGRAM, &psion2_state::psionxp_mem);
+
+	m_ram->set_default_size("16K");
+
+	subdevice<software_list_device>("pack_list")->set_filter("XP");
 }
 
-void psion_state::psionp350(machine_config &config)
+void psion2_state::psionla(machine_config &config)
 {
-	psion_2lines(config);
+	psionxp(config);
 
-	m_maincpu->set_addrmap(AS_PROGRAM, &psion_state::psionp350_mem);
+	m_maincpu->set_addrmap(AS_PROGRAM, &psion2_state::psionla_mem);
 
-	NVRAM(config, "nvram2", nvram_device::DEFAULT_ALL_0); // paged RAM
+	m_ram->set_default_size("32K");
 }
 
-void psion_state::psionlz(machine_config &config)
+void psion2_state::psionp200(machine_config &config)
 {
-	psion_4lines(config);
+	psionla(config);
 
-	m_maincpu->set_addrmap(AS_PROGRAM, &psion_state::psionlz_mem);
+	subdevice<software_list_device>("pack_list")->set_filter("POS");
+}
 
-	NVRAM(config, "nvram2", nvram_device::DEFAULT_ALL_0); // paged RAM
+void psion2_state::psionp350(machine_config &config)
+{
+	psionla(config);
+
+	m_ram->set_default_size("96K");
+
+	subdevice<software_list_device>("pack_list")->set_filter("POS");
+}
+
+void psion2_state::psionlz(machine_config &config)
+{
+	psionla(config);
+
+	/* video hardware */
+	m_screen->set_size(6*20, 9*4);
+	m_screen->set_visarea_full();
+
+	m_lcdc->set_lcd_size(4, 20);
+	m_lcdc->set_pixel_update_cb(FUNC(psion2_state::lz_pixel_update));
+
+	subdevice<software_list_device>("pack_list")->set_filter("LZ");
+}
+
+void psion2_state::psionlz64(machine_config &config)
+{
+	psionlz(config);
+
+	m_ram->set_default_size("64K");
+
+	subdevice<software_list_device>("pack_list")->set_filter("LZ,LZ64");
+}
+
+void psion2_state::psionp432(machine_config &config)
+{
+	psionlz(config);
+
+	subdevice<software_list_device>("pack_list")->set_filter("POS");
+}
+
+void psion2_state::psionp464(machine_config &config)
+{
+	psionlz64(config);
+
+	subdevice<software_list_device>("pack_list")->set_filter("POS");
 }
 
 /* ROM definition */
 
 ROM_START( psion1 )
 	ROM_REGION( 0x1000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v1", "Organiser I")
-	ROMX_LOAD( "psion1.rom",  0x0000, 0x1000, CRC(7e2609c1) SHA1(a3320ea8ac3ab9e0039ee16f7c571731adde5869), ROM_BIOS(0))
+	ROM_LOAD("psion1.rom", 0x0000, 0x1000, CRC(7e2609c1) SHA1(a3320ea8ac3ab9e0039ee16f7c571731adde5869))
 ROM_END
 
 ROM_START( psioncm )
-	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
+	ROM_REGION( 0x8000, "maincpu", ROMREGION_ERASEFF )
+	ROM_DEFAULT_BIOS( "v33" )
 	ROM_SYSTEM_BIOS(0, "v24", "CM v2.4")
-	ROMX_LOAD("24-cm.dat",    0x8000, 0x8000,  CRC(f6798394) SHA1(736997f0db9a9ee50d6785636bdc3f8ff1c33c66), ROM_BIOS(0))
+	ROMX_LOAD("24-cm.rom",    0x0000, 0x8000,  CRC(f6798394) SHA1(736997f0db9a9ee50d6785636bdc3f8ff1c33c66), ROM_BIOS(0))
 	ROM_SYSTEM_BIOS(1, "v26", "CM v2.6")
-	ROMX_LOAD("26-cm.rom",    0x8000, 0x8000,  CRC(21b7c94c) SHA1(e0a3168c96a3f0b37b8698e86574e40597fe3c62), ROM_BIOS(1))
+	ROMX_LOAD("26-cm.rom",    0x0000, 0x8000,  CRC(21b7c94c) SHA1(e0a3168c96a3f0b37b8698e86574e40597fe3c62), ROM_BIOS(1))
 	ROM_SYSTEM_BIOS(2, "v33", "CM v3.3")
-	ROMX_LOAD("33-cm.rom",    0x8000, 0x8000,  CRC(5c10b167) SHA1(6deea00fe648bddae1d61a22858023bc80277ea0), ROM_BIOS(2))
-	ROM_SYSTEM_BIOS(3, "v33f","CM v3.3 French")
-	ROMX_LOAD("33-cmf.rom",   0x8000, 0x8000,  CRC(4d626ce2) SHA1(82b96f11a0abfc1931b6022b84733d975ad7ab2b), ROM_BIOS(3))
-	ROM_SYSTEM_BIOS(4, "v36f","CM v3.6 French")
-	ROMX_LOAD("36-cmf.rom",   0x8000, 0x8000,  CRC(beabe0f5) SHA1(a5ef3bb92190a257cb0e94d58b2c23935436edeb), ROM_BIOS(4))
+	ROMX_LOAD("33-cm.rom",    0x0000, 0x8000,  CRC(5c10b167) SHA1(6deea00fe648bddae1d61a22858023bc80277ea0), ROM_BIOS(2))
+	ROM_SYSTEM_BIOS(3, "v33f", "CM v3.3 French")
+	ROMX_LOAD("33-cmf.rom",   0x0000, 0x8000,  CRC(4d626ce2) SHA1(82b96f11a0abfc1931b6022b84733d975ad7ab2b), ROM_BIOS(3))
+	ROM_SYSTEM_BIOS(4, "v36f", "CM v3.6 French")
+	ROMX_LOAD("36-cmf.rom",   0x0000, 0x8000,  CRC(beabe0f5) SHA1(a5ef3bb92190a257cb0e94d58b2c23935436edeb), ROM_BIOS(4))
 ROM_END
 
 ROM_START( psionxp )
-	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v26", "XP v2.6")
-	ROMX_LOAD( "26-xp.rom",    0x8000, 0x8000,  CRC(a81db40f) SHA1(af72d94ccee1fa1dade8776bdbd39920665a68b7), ROM_BIOS(0) )
+	ROM_REGION( 0x8000, "maincpu", ROMREGION_ERASEFF )
+	ROM_DEFAULT_BIOS( "v31" )
+	ROM_SYSTEM_BIOS(0, "v24", "XP v2.4")
+	ROMX_LOAD("24-xp.rom",    0x0000, 0x8000,  CRC(3407062c) SHA1(c3818f3f0865cc235905bd7ef6cba325e44fa076), ROM_BIOS(0))
+	ROM_SYSTEM_BIOS(1, "v26", "XP v2.6")
+	ROMX_LOAD("26-xp.rom",    0x0000, 0x8000,  CRC(a81db40f) SHA1(af72d94ccee1fa1dade8776bdbd39920665a68b7), ROM_BIOS(1))
+	ROM_SYSTEM_BIOS(2, "v31", "XP v3.1")
+	ROMX_LOAD("31-xp.rom",    0x0000, 0x8000,  CRC(cb10b6bf) SHA1(af5e82f62a149ff0dfa6e60414c928649a2abaaa), ROM_BIOS(2))
 ROM_END
 
 ROM_START( psionla )
-	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v33", "LA v3.3")
-	ROMX_LOAD("33-la.dat",    0x8000, 0x8000,  CRC(02668ed4) SHA1(e5d4ee6b1cde310a2970ffcc6f29a0ce09b08c46), ROM_BIOS(0))
-	ROM_SYSTEM_BIOS(1, "v34g", "LA v3.4 German")
-	ROMX_LOAD("34-lag.rom",   0x8000, 0x8000,  CRC(13a92c4b) SHA1(dab8bd6a41a5fd509c5ad4b0b0ab80d14f2c421a), ROM_BIOS(1))
-	ROM_SYSTEM_BIOS(2, "v36", "LA v3.6")
-	ROMX_LOAD("36-la.rom",    0x8000, 0x8000,  CRC(7442c7f6) SHA1(94f15bd06bd750be70fa4a4ab588237c5a703f65), ROM_BIOS(2))
-	ROM_SYSTEM_BIOS(3, "v30", "LA v3.0")
-	ROMX_LOAD("30-lahp.rom",    0x8000, 0x8000,  CRC(50192528) SHA1(c556d53f70bf5ecae756b2ebfc6d954912316bbe), ROM_BIOS(3))
+	ROM_REGION( 0x8000, "maincpu", ROMREGION_ERASEFF )
+	ROM_DEFAULT_BIOS( "v36" )
+	ROM_SYSTEM_BIOS(0, "v30hp", "LA v3.0 Hand Held Products")
+	ROMX_LOAD("30-lahp.rom",  0x0000, 0x8000,  CRC(50192528) SHA1(c556d53f70bf5ecae756b2ebfc6d954912316bbe), ROM_BIOS(0))
+	ROM_SYSTEM_BIOS(1, "v33", "LA v3.3")
+	ROMX_LOAD("33-la.rom",    0x0000, 0x8000,  CRC(02668ed4) SHA1(e5d4ee6b1cde310a2970ffcc6f29a0ce09b08c46), ROM_BIOS(1))
+	ROM_SYSTEM_BIOS(2, "v34g", "LA v3.4 German")
+	ROMX_LOAD("34-lag.rom",   0x0000, 0x8000,  CRC(13a92c4b) SHA1(dab8bd6a41a5fd509c5ad4b0b0ab80d14f2c421a), ROM_BIOS(2))
+	ROM_SYSTEM_BIOS(3, "v36", "LA v3.6")
+	ROMX_LOAD("36-la.rom",    0x0000, 0x8000,  CRC(7442c7f6) SHA1(94f15bd06bd750be70fa4a4ab588237c5a703f65), ROM_BIOS(3))
 	ROM_SYSTEM_BIOS(4, "v36f", "LA v3.6 French")
-	ROMX_LOAD("36-laf.rom",    0x8000, 0x8000, CRC(036ef00e) SHA1(98f303273e570e94a1e25a58cf1ffcec0db32165), ROM_BIOS(4))
-ROM_END
-
-ROM_START( psionp200 )
-	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v33", "POS200a v3.3")
-	ROMX_LOAD("33-p200a.rom", 0x8000, 0x8000, CRC(91e94998) SHA1(e9e8106eb9283d20452697859894aa407cc07bd1), ROM_BIOS(0))
-	ROM_SYSTEM_BIOS(1, "v36", "POS200 v3.6")
-	ROMX_LOAD("36-p200.rom",  0x8000, 0x8000, CRC(4569ef5b) SHA1(8c275474cc6e3f50156f0b6e32121cadd14ea8be), ROM_BIOS(1))
-	ROM_SYSTEM_BIOS(2, "v36a", "POS200a v3.6")
-	ROMX_LOAD("36-p200a.rom", 0x8000, 0x8000, CRC(36cceeb7) SHA1(57069812c5a16babfff91dc7d7e0842e5dc68652), ROM_BIOS(2))
-	ROM_SYSTEM_BIOS(3, "v36b", "POS250 v3.6")
-	ROMX_LOAD("36-p250.rom",  0x8000, 0x8000, CRC(235cc76a) SHA1(3229cdff4b049a1fbf9a758ce3abf3fdc9b547c9), ROM_BIOS(3))
-ROM_END
-
-ROM_START( psionp350 )
-	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v36", "POS350 v3.6")
-	ROMX_LOAD("36-p350.dat",  0x8000, 0x8000,  CRC(3a371a74) SHA1(9167210b2c0c3bd196afc08ca44ab23e4e62635e), ROM_BIOS(0))
-	ROM_SYSTEM_BIOS(1, "v38", "POS350 v3.8")
-	ROMX_LOAD("38-p350.dat",  0x8000, 0x8000,  CRC(1b8b082f) SHA1(a3e875a59860e344f304a831148a7980f28eaa4a), ROM_BIOS(1))
+	ROMX_LOAD("36-laf.rom",   0x0000, 0x8000,  CRC(036ef00e) SHA1(98f303273e570e94a1e25a58cf1ffcec0db32165), ROM_BIOS(4))
+	ROM_SYSTEM_BIOS(5, "v36g", "LA v3.6 German")
+	ROMX_LOAD("36-lag.rom",   0x0000, 0x8000,  CRC(33c6b4d4) SHA1(81d665ce0fa325996d52004655349162093d60a6), ROM_BIOS(5))
 ROM_END
 
 ROM_START( psionlam )
-	ROM_REGION( 0x18000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v37", "LA v3.7")
-	ROMX_LOAD("37-lam.dat",   0x8000, 0x10000, CRC(7ee3a1bc) SHA1(c7fbd6c8e47c9b7d5f636e9f56e911b363d6796b), ROM_BIOS(0))
+	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
+	ROM_SYSTEM_BIOS(0, "v37", "LA v3.7 Multilingual")
+	ROMX_LOAD("37-lam.dat",   0x0000, 0x10000, CRC(7ee3a1bc) SHA1(c7fbd6c8e47c9b7d5f636e9f56e911b363d6796b), ROM_BIOS(0))
 ROM_END
 
-ROM_START( psionlz64 )
-	ROM_REGION( 0x18000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v44", "LZ64 v4.4")
-	ROMX_LOAD("44-lz64.dat",  0x8000, 0x10000, CRC(aa487913) SHA1(5a44390f63fc8c1bc94299ab2eb291bc3a5b989a), ROM_BIOS(0))
-	ROM_SYSTEM_BIOS(1, "v46si", "LZ64 v4.6 Spanish / Italian")
-	ROMX_LOAD("46-lz64i.rom", 0x8000, 0x10000, CRC(c96c7e65) SHA1(1b4af43657bbd3ecd92f370762bde166047b85e2), ROM_BIOS(1))
-	ROM_SYSTEM_BIOS(2, "v43", "LZ64 v4.3")
-	ROMX_LOAD("43-lz64.rom",  0x8000, 0x10000, CRC(57e7a372) SHA1(46c2da1cfe991c0c1f2486e4aa28388767937ddd), ROM_BIOS(2))
-	ROM_SYSTEM_BIOS(3, "v46a", "LZ64 v4.6a")
-	ROMX_LOAD("46a-lz64.rom", 0x8000, 0x10000, CRC(9b0d5a7a) SHA1(f1cdd6ef43cd65ef18e148deca0500f0c1ad2f80), ROM_BIOS(3))
-	ROM_SYSTEM_BIOS(4, "v46b", "LZ64 v4.6b")
-	ROMX_LOAD("46b-lz64.rom", 0x8000, 0x10000, CRC(8d1101e2) SHA1(eddd0c3a2881667a1485b0d66f82f8c7792995c2), ROM_BIOS(4))
-	ROM_SYSTEM_BIOS(5, "v45", "LZ64 v4.5")
-	ROMX_LOAD("45-lz64.rom",  0x8000, 0x10000, CRC(4fbd5d88) SHA1(43f97549d2060840aa6313d526000530f384a08f), ROM_BIOS(5))
-
-	ROM_REGION( 0x1000, "hd44780", 0 )
-	ROM_LOAD("psion_lz_charset.bin",    0x0000, 0x1000,  BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
+ROM_START( psionp200 )
+	ROM_REGION( 0x8000, "maincpu", ROMREGION_ERASEFF )
+	ROM_SYSTEM_BIOS(0, "v36", "POS 200 v3.6")
+	ROMX_LOAD("36-p200.rom",  0x0000, 0x8000,  CRC(4569ef5b) SHA1(8c275474cc6e3f50156f0b6e32121cadd14ea8be), ROM_BIOS(0))
 ROM_END
 
-ROM_START( psionlz64s )
-	ROM_REGION( 0x18000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v46", "LZ64 v4.6")
-	ROMX_LOAD("46-lz64s.dat", 0x8000, 0x10000, CRC(328d9772) SHA1(7f9e2d591d59ecfb0822d7067c2fe59542ea16dd), ROM_BIOS(0))
+ROM_START( psionp200a )
+	ROM_REGION( 0x8000, "maincpu", ROMREGION_ERASEFF )
+	ROM_DEFAULT_BIOS( "v36" )
+	ROM_SYSTEM_BIOS(0, "v33", "Alpha POS 200 v3.3")
+	ROMX_LOAD("33-p200a.rom", 0x0000, 0x8000,  CRC(91e94998) SHA1(e9e8106eb9283d20452697859894aa407cc07bd1), ROM_BIOS(0))
+	ROM_SYSTEM_BIOS(1, "v36", "Alpha POS 200 v3.6")
+	ROMX_LOAD("36-p200a.rom", 0x0000, 0x8000,  CRC(36cceeb7) SHA1(57069812c5a16babfff91dc7d7e0842e5dc68652), ROM_BIOS(1))
+ROM_END
 
-	ROM_REGION( 0x1000, "hd44780", 0 )
-	ROM_LOAD("psion_lz_charset.bin",    0x0000, 0x1000,  BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
+ROM_START( psionp250 )
+	ROM_REGION( 0x8000, "maincpu", ROMREGION_ERASEFF )
+	ROM_SYSTEM_BIOS(0, "v36b", "POS 250 v3.6")
+	ROMX_LOAD("36-p250.rom",  0x0000, 0x8000,  CRC(235cc76a) SHA1(3229cdff4b049a1fbf9a758ce3abf3fdc9b547c9), ROM_BIOS(0))
+ROM_END
+
+ROM_START( psionp350 )
+	ROM_REGION( 0x8000, "maincpu", ROMREGION_ERASEFF )
+	ROM_DEFAULT_BIOS( "v36" )
+	ROM_SYSTEM_BIOS(0, "v36", "POS 350 v3.6")
+	ROMX_LOAD("36-p350.rom",  0x0000, 0x8000,  CRC(3a371a74) SHA1(9167210b2c0c3bd196afc08ca44ab23e4e62635e), ROM_BIOS(0))
+	ROM_SYSTEM_BIOS(1, "v38", "POS 350 v3.8")
+	ROMX_LOAD("38-p350.rom",  0x0000, 0x8000,  CRC(1b8b082f) SHA1(a3e875a59860e344f304a831148a7980f28eaa4a), ROM_BIOS(1))
 ROM_END
 
 ROM_START( psionlz )
-	ROM_REGION( 0x18000, "maincpu", ROMREGION_ERASEFF )
-	ROM_SYSTEM_BIOS(0, "v46", "LZ v4.6")
-	ROMX_LOAD("46-lz.dat",    0x8000, 0x10000, CRC(22715f48) SHA1(cf460c81cadb53eddb7afd8dadecbe8c38ea3fc2), ROM_BIOS(0))
-	ROM_SYSTEM_BIOS(1, "v42", "LZ v4.2")
-	ROMX_LOAD("42-lz.rom",    0x8000, 0x10000, CRC(f2d6ad47) SHA1(ee8315ae872463068d805c6e0b71f62ae8eb65be), ROM_BIOS(1))
-	ROM_SYSTEM_BIOS(2, "v44", "LZ v4.4")
-	ROMX_LOAD("44-lz.rom",    0x8000, 0x10000, CRC(4a0a990b) SHA1(dde0ba69a4a7f02b610ad6bd69a8b8552b060223), ROM_BIOS(2))
-	ROM_SYSTEM_BIOS(3, "v45", "LZ v4.5")
-	ROMX_LOAD("45-lz.rom",    0x8000, 0x10000, CRC(f95d8f39) SHA1(cb64152c2418bf730c89999d1b13c1d1ada1f082), ROM_BIOS(3))
-	ROM_SYSTEM_BIOS(4, "v45s", "LZ v4.5S")
-	ROMX_LOAD("45-lzs.rom",   0x8000, 0x10000, CRC(2d082d7f) SHA1(fcd00864a0cc617e61997240945ea70a8e9fa211), ROM_BIOS(4))
+	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
+	ROM_DEFAULT_BIOS( "v46" )
+	ROM_SYSTEM_BIOS(0, "v42", "LZ v4.2 English, French, German")
+	ROMX_LOAD("42-lz.rom",    0x0000, 0x10000, CRC(f2d6ad47) SHA1(ee8315ae872463068d805c6e0b71f62ae8eb65be), ROM_BIOS(0))
+	ROM_SYSTEM_BIOS(1, "v44", "LZ v4.4 English, French, German")
+	ROMX_LOAD("44-lz.rom",    0x0000, 0x10000, CRC(4a0a990b) SHA1(dde0ba69a4a7f02b610ad6bd69a8b8552b060223), ROM_BIOS(1))
+	ROM_SYSTEM_BIOS(2, "v45", "LZ v4.5 English, French, German")
+	ROMX_LOAD("45-lz.rom",    0x0000, 0x10000, CRC(f95d8f39) SHA1(cb64152c2418bf730c89999d1b13c1d1ada1f082), ROM_BIOS(2))
+	ROM_SYSTEM_BIOS(3, "v45i", "LZ v4.5 English, Spanish, Italian")
+	ROMX_LOAD("45-lzi.rom",   0x0000, 0x10000, CRC(202b556d) SHA1(39f061c4b94a1371bfe62484828a8ce424d7315c), ROM_BIOS(3))
+	ROM_SYSTEM_BIOS(4, "v45s", "LZ v4.5 English, Swedish, Danish")
+	ROMX_LOAD("45-lzs.rom",   0x0000, 0x10000, CRC(2d082d7f) SHA1(fcd00864a0cc617e61997240945ea70a8e9fa211), ROM_BIOS(4))
+	ROM_SYSTEM_BIOS(5, "v46", "LZ v4.6 English, French, German")
+	ROMX_LOAD("46-lz.rom",    0x0000, 0x10000, CRC(22715f48) SHA1(cf460c81cadb53eddb7afd8dadecbe8c38ea3fc2), ROM_BIOS(5))
+	ROM_SYSTEM_BIOS(6, "v46i", "LZ v4.6 English, Spanish, Italian")
+	ROMX_LOAD("46-lzi.rom",   0x0000, 0x10000, CRC(ee50b6e9) SHA1(f1821ad179b018d6b22129ef4e8e8b23f452b2f6), ROM_BIOS(6))
 
 	ROM_REGION( 0x1000, "hd44780", 0 )
-	ROM_LOAD("psion_lz_charset.bin",    0x0000, 0x1000,  BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
+	ROM_LOAD("psion_lz_charset.bin", 0x0000, 0x1000, BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
+ROM_END
+
+ROM_START( psionlz64 )
+	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
+	ROM_DEFAULT_BIOS( "v46a" )
+	ROM_SYSTEM_BIOS(0, "v42", "LZ64 v4.2 English, French, German")
+	ROMX_LOAD("42-lz64.rom",  0x0000, 0x10000, CRC(2df76f5a) SHA1(4255bc2abfc6f6cb666c0464a86d4ac98050268e), ROM_BIOS(0))
+	ROM_SYSTEM_BIOS(1, "v43", "LZ64 v4.3 English, French, German")
+	ROMX_LOAD("43-lz64.rom",  0x0000, 0x10000, CRC(57e7a372) SHA1(46c2da1cfe991c0c1f2486e4aa28388767937ddd), ROM_BIOS(1))
+	ROM_SYSTEM_BIOS(2, "v44", "LZ64 v4.4 English, French, German")
+	ROMX_LOAD("44-lz64.rom",  0x0000, 0x10000, CRC(aa487913) SHA1(5a44390f63fc8c1bc94299ab2eb291bc3a5b989a), ROM_BIOS(2))
+	ROM_SYSTEM_BIOS(3, "v45", "LZ64 v4.5 English, French, German")
+	ROMX_LOAD("45-lz64.rom",  0x0000, 0x10000, CRC(4fbd5d88) SHA1(43f97549d2060840aa6313d526000530f384a08f), ROM_BIOS(3))
+	ROM_SYSTEM_BIOS(4, "v46a", "LZ64 v4.6a English, French, German")
+	ROMX_LOAD("46a-lz64.rom", 0x0000, 0x10000, CRC(9b0d5a7a) SHA1(f1cdd6ef43cd65ef18e148deca0500f0c1ad2f80), ROM_BIOS(4))
+	ROM_SYSTEM_BIOS(5, "v46b", "LZ64 v4.6b English, French, German")
+	ROMX_LOAD("46b-lz64.rom", 0x0000, 0x10000, CRC(8d1101e2) SHA1(eddd0c3a2881667a1485b0d66f82f8c7792995c2), ROM_BIOS(5))
+	ROM_SYSTEM_BIOS(6, "v46i", "LZ64 v4.6 English, Spanish, Italian")
+	ROMX_LOAD("46-lz64i.rom", 0x0000, 0x10000, CRC(c96c7e65) SHA1(1b4af43657bbd3ecd92f370762bde166047b85e2), ROM_BIOS(6))
+	ROM_SYSTEM_BIOS(7, "v46s", "LZ64 v4.6 English, Swedish, Danish")
+	ROMX_LOAD("46-lz64s.rom", 0x0000, 0x10000, CRC(328d9772) SHA1(7f9e2d591d59ecfb0822d7067c2fe59542ea16dd), ROM_BIOS(7))
+
+	ROM_REGION( 0x1000, "hd44780", 0 )
+	ROM_LOAD("psion_lz_charset.bin", 0x0000, 0x1000, BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
+ROM_END
+
+ROM_START( psionp432 )
+	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
+	ROM_SYSTEM_BIOS(0, "v46", "POS432 v4.6")
+	ROMX_LOAD("46-p432n.rom",  0x0000, 0x10000, CRC(6683737a) SHA1(2c6bd9938f1b1d762adc8d45802c24f007e3445a), ROM_BIOS(0))
+
+	ROM_REGION( 0x1000, "hd44780", 0 )
+	ROM_LOAD("psion_lz_charset.bin", 0x0000, 0x1000, BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
 ROM_END
 
 ROM_START( psionp464 )
-	ROM_REGION( 0x18000, "maincpu", ROMREGION_ERASEFF )
+	ROM_REGION( 0x10000, "maincpu", ROMREGION_ERASEFF )
 	ROM_SYSTEM_BIOS(0, "v46", "POS464 v4.6")
-	ROMX_LOAD( "46-p464.dat",  0x8000, 0x10000, CRC(672a0945) SHA1(d2a6e3fe1019d1bd7ae4725e33a0b9973f8cd7d8), ROM_BIOS(0))
+	ROMX_LOAD("46-p464.rom",  0x0000, 0x10000, CRC(672a0945) SHA1(d2a6e3fe1019d1bd7ae4725e33a0b9973f8cd7d8), ROM_BIOS(0))
 
 	ROM_REGION( 0x1000, "hd44780", 0 )
-	ROM_LOAD( "psion_lz_charset.bin",    0x0000, 0x1000,  BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
+	ROM_LOAD("psion_lz_charset.bin", 0x0000, 0x1000, BAD_DUMP CRC(44bff6f6) SHA1(aef544548b783d608a7d55456f6c46f421a11ed7))
 ROM_END
 
-/* Driver */
+} // anonymous namespace
 
-//    YEAR  NAME        PARENT   COMPAT  MACHINE    INPUT   CLASS         INIT        COMPANY  FULLNAME              FLAGS
-COMP( 1984, psion1,     0,       0,      psion1,    psion1, psion1_state, empty_init, "Psion", "Organiser I",        MACHINE_NOT_WORKING )
-COMP( 1986, psioncm,    0,       0,      psioncm,   psion,  psion_state,  empty_init, "Psion", "Organiser II CM",    MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1986, psionla,    psioncm, 0,      psionla,   psion,  psion_state,  empty_init, "Psion", "Organiser II LA",    MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1986, psionxp,    psioncm, 0,      psionla,   psion,  psion_state,  empty_init, "Psion", "Organiser II XP",    MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1986, psionp200,  psioncm, 0,      psionp350, psion,  psion_state,  empty_init, "Psion", "Organiser II P200",  MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1986, psionp350,  psioncm, 0,      psionp350, psion,  psion_state,  empty_init, "Psion", "Organiser II P350",  MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1986, psionlam,   psioncm, 0,      psionlam,  psion,  psion_state,  empty_init, "Psion", "Organiser II LAM",   MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1989, psionlz,    0,       0,      psionlz,   psion,  psion_state,  empty_init, "Psion", "Organiser II LZ",    MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1989, psionlz64,  psionlz, 0,      psionlz,   psion,  psion_state,  empty_init, "Psion", "Organiser II LZ64",  MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1989, psionlz64s, psionlz, 0,      psionlz,   psion,  psion_state,  empty_init, "Psion", "Organiser II LZ64S", MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
-COMP( 1989, psionp464,  psionlz, 0,      psionlz,   psion,  psion_state,  empty_init, "Psion", "Organiser II P464",  MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+
+//    YEAR  NAME        PARENT   COMPAT  MACHINE    INPUT    CLASS         INIT        COMPANY  FULLNAME                         FLAGS
+COMP( 1984, psion1,     0,       0,      psion1,    psion1,  psion1_state, empty_init, "Psion", "Organiser I",                   MACHINE_NOT_WORKING )
+COMP( 1986, psioncm,    0,       0,      psioncm,   psion2,  psion2_state, empty_init, "Psion", "Organiser II CM",               MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1986, psionxp,    psioncm, 0,      psionxp,   psion2,  psion2_state, empty_init, "Psion", "Organiser II XP",               MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1986, psionla,    psioncm, 0,      psionla,   psion2,  psion2_state, empty_init, "Psion", "Organiser II LA",               MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1986, psionlam,   psioncm, 0,      psionla,   psion2,  psion2_state, empty_init, "Psion", "Organiser II LA Multilingual",  MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1986, psionp200,  psioncm, 0,      psionp200, psion2n, psion2_state, empty_init, "Psion", "Organiser II POS 200",          MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1986, psionp200a, psioncm, 0,      psionp200, psion2a, psion2_state, empty_init, "Psion", "Organiser II Alpha POS 200",    MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1986, psionp250,  psioncm, 0,      psionp200, psion2,  psion2_state, empty_init, "Psion", "Organiser II P 250",            MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1986, psionp350,  psioncm, 0,      psionp350, psion2,  psion2_state, empty_init, "Psion", "Organiser II P 350",            MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1989, psionlz,    0,       0,      psionlz,   psion2,  psion2_state, empty_init, "Psion", "Organiser II LZ",               MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1989, psionlz64,  psionlz, 0,      psionlz64, psion2,  psion2_state, empty_init, "Psion", "Organiser II LZ64",             MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1989, psionp432,  psionlz, 0,      psionp432, psion2n, psion2_state, empty_init, "Psion", "Organiser II P 432",            MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
+COMP( 1989, psionp464,  psionlz, 0,      psionp464, psion2,  psion2_state, empty_init, "Psion", "Organiser II P 464",            MACHINE_SUPPORTS_SAVE | MACHINE_IMPERFECT_GRAPHICS )
diff --git a/src/mame/psion/psion.h b/src/mame/psion/psion.h
deleted file mode 100644
index c77f6b134fe..00000000000
--- a/src/mame/psion/psion.h
+++ /dev/null
@@ -1,120 +0,0 @@
-// license:BSD-3-Clause
-// copyright-holders:Sandro Ronco
-/***************************************************************************
-
-        Psion Organiser II series
-
-****************************************************************************/
-#ifndef MAME_PSION_PSION_H
-#define MAME_PSION_PSION_H
-
-#pragma once
-
-#include "cpu/m6800/m6801.h"
-#include "machine/nvram.h"
-#include "psion_pack.h"
-#include "machine/timer.h"
-#include "video/hd44780.h"
-#include "sound/beep.h"
-#include "emupal.h"
-
-
-// ======================> psion_state
-
-class psion_state : public driver_device
-{
-public:
-	psion_state(const machine_config &mconfig, device_type type, const char *tag)
-		: driver_device(mconfig, type, tag)
-		, m_maincpu(*this, "maincpu")
-		, m_lcdc(*this, "hd44780")
-		, m_beep(*this, "beeper")
-		, m_pack1(*this, "pack1")
-		, m_pack2(*this, "pack2")
-		, m_nvram1(*this, "nvram1")
-		, m_nvram2(*this, "nvram2")
-		, m_ram(*this, "ram")
-		, m_kb_lines(*this, "K%u", 1U)
-	{ }
-
-	void psion_2lines(machine_config &config);
-	void psion_4lines(machine_config &config);
-	void psionlam(machine_config &config);
-	void psioncm(machine_config &config);
-	void psionlz(machine_config &config);
-	void psionla(machine_config &config);
-	void psionp350(machine_config &config);
-
-	DECLARE_INPUT_CHANGED_MEMBER(psion_on);
-
-protected:
-	required_device<hd6301x_cpu_device> m_maincpu;
-	required_device<hd44780_device> m_lcdc;
-	required_device<beep_device> m_beep;
-	required_device<datapack_device> m_pack1;
-	required_device<datapack_device> m_pack2;
-	required_device<nvram_device> m_nvram1;
-	optional_device<nvram_device> m_nvram2;
-
-	uint16_t m_kb_counter = 0;
-	bool m_enable_nmi = false;
-	uint8_t m_pulse = 0;
-
-	// RAM/ROM banks
-	required_shared_ptr<uint8_t> m_ram;
-	std::unique_ptr<uint8_t[]> m_paged_ram;
-	uint8_t m_rom_bank = 0;
-	uint8_t m_ram_bank = 0;
-	uint8_t m_ram_bank_count = 0;
-	uint8_t m_rom_bank_count = 0;
-
-	required_ioport_array<7> m_kb_lines;
-
-	virtual void machine_start() override ATTR_COLD;
-	virtual void machine_reset() override ATTR_COLD;
-	void nvram_init(nvram_device &nvram, void *data, size_t size);
-
-	uint8_t kb_read();
-	void update_banks();
-	void port2_w(offs_t offset, uint8_t data, uint8_t ddr);
-	uint8_t port2_r();
-	uint8_t port5_r();
-	void port6_w(uint8_t data);
-	uint8_t port6_r();
-	void io_rw(uint16_t offset);
-	void io_w(offs_t offset, uint8_t data);
-	uint8_t io_r(offs_t offset);
-	void psion_palette(palette_device &palette) const;
-	TIMER_DEVICE_CALLBACK_MEMBER(nmi_timer);
-
-	HD44780_PIXEL_UPDATE(lz_pixel_update);
-	void psion_int_reg(address_map &map) ATTR_COLD;
-	void psioncm_mem(address_map &map) ATTR_COLD;
-	void psionla_mem(address_map &map) ATTR_COLD;
-	void psionlam_mem(address_map &map) ATTR_COLD;
-	void psionlz_mem(address_map &map) ATTR_COLD;
-	void psionp350_mem(address_map &map) ATTR_COLD;
-};
-
-
-class psion1_state : public psion_state
-{
-public:
-	psion1_state(const machine_config &mconfig, device_type type, const char *tag)
-		: psion_state(mconfig, type, tag)
-	{ }
-
-	void psion1(machine_config &config);
-
-private:
-	virtual void machine_reset() override ATTR_COLD;
-
-	uint8_t reset_kb_counter_r();
-	uint8_t inc_kb_counter_r();
-	uint8_t switchoff_r();
-
-	HD44780_PIXEL_UPDATE(psion1_pixel_update);
-	void psion1_mem(address_map &map) ATTR_COLD;
-};
-
-#endif // MAME_PSION_PSION_H
diff --git a/src/mame/psion/psion_pack.cpp b/src/mame/psion/psion_pack.cpp
index cafb221303a..879f8fe335c 100644
--- a/src/mame/psion/psion_pack.cpp
+++ b/src/mame/psion/psion_pack.cpp
@@ -2,7 +2,7 @@
 // copyright-holders:Sandro Ronco
 /****************************************************************************
 
-    psion_pack.c
+    psion_pack.cpp
 
     Psion Organiser II Datapack emulation
 
@@ -67,6 +67,7 @@ DEFINE_DEVICE_TYPE(PSION_DATAPACK, datapack_device, "datapack", "Psion Datapack"
 datapack_device::datapack_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
 	: device_t(mconfig, PSION_DATAPACK, tag, owner, clock)
 	, device_memcard_image_interface(mconfig, *this)
+	, m_interface(nullptr)
 {
 }
 
diff --git a/src/mame/psion/psion_pack.h b/src/mame/psion/psion_pack.h
index 27e1400de1a..dcb5e8ecfa4 100644
--- a/src/mame/psion/psion_pack.h
+++ b/src/mame/psion/psion_pack.h
@@ -23,16 +23,18 @@ class datapack_device : public device_t,
 {
 public:
 	// construction/destruction
-	datapack_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
+	datapack_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock = 0);
 	virtual ~datapack_device();
 
+	void set_interface(const char *interface) { m_interface = interface; }
+
 	// device_image_interface implementation
 	virtual std::pair<std::error_condition, std::string> call_load() override;
 	virtual void call_unload() override;
 	virtual std::pair<std::error_condition, std::string> call_create(int format_type, util::option_resolution *create_args) override;
 
 	virtual bool is_reset_on_load() const noexcept override { return false; }
-	virtual const char *image_interface() const noexcept override { return "psion_pack"; }
+	virtual const char *image_interface() const noexcept override { return m_interface; }
 	virtual const char *file_extensions() const noexcept override { return "opk"; }
 	virtual const char *image_type_name() const noexcept override { return "datapack"; }
 	virtual const char *image_brief_type_name() const noexcept override { return "dpak"; }
@@ -64,6 +66,8 @@ private:
 	uint16_t m_counter = 0;           //address counter
 	uint8_t  m_page = 0;              //active page (only for paged Datapack)
 	uint8_t  m_segment = 0;           //active segment (only for segmented Datapack)
+
+	const char *m_interface;
 };