diff --git a/scripts/src/bus.lua b/scripts/src/bus.lua
index 415826bbfb6..1540f2c8d54 100644
--- a/scripts/src/bus.lua
+++ b/scripts/src/bus.lua
@@ -190,6 +190,19 @@ if (BUSES["ADAMNET"]~=null) then
 	}
 end
 
+---------------------------------------------------
+--
+--@src/devices/bus/adb/adb.h,BUSES["ADB"] = true
+---------------------------------------------------
+
+if (BUSES["ADB"]~=null) then
+	files {
+		MAME_DIR .. "src/devices/bus/adb/adb.cpp",
+		MAME_DIR .. "src/devices/bus/adb/adb.h",
+		MAME_DIR .. "src/devices/bus/adb/adbhle.cpp",
+		MAME_DIR .. "src/devices/bus/adb/adbhle.h",
+	}
+end
 
 ---------------------------------------------------
 --
diff --git a/scripts/target/mame/arcade.lua b/scripts/target/mame/arcade.lua
index 40c0370ed1e..b61d57dee0a 100644
--- a/scripts/target/mame/arcade.lua
+++ b/scripts/target/mame/arcade.lua
@@ -754,6 +754,7 @@ MACHINES["VRENDER0"] = true
 --BUSES["ABCKB"] = true
 --BUSES["ADAM"] = true
 --BUSES["ADAMNET"] = true
+--BUSES["ADB"] = true
 --BUSES["APF"] = true
 BUSES["AMIGA_KEYBOARD"] = true
 --BUSES["ARCADIA"] = true
diff --git a/scripts/target/mame/mess.lua b/scripts/target/mame/mess.lua
index 8d12ca214d9..edd03a28e6f 100644
--- a/scripts/target/mame/mess.lua
+++ b/scripts/target/mame/mess.lua
@@ -824,6 +824,7 @@ BUSES["ABCKB"] = true
 BUSES["ACORN"] = true
 BUSES["ADAM"] = true
 BUSES["ADAMNET"] = true
+BUSES["ADB"] = true
 BUSES["APF"] = true
 BUSES["APRICOT_EXPANSION"] = true
 BUSES["APRICOT_KEYBOARD"] = true
diff --git a/src/devices/bus/adb/adb.cpp b/src/devices/bus/adb/adb.cpp
new file mode 100644
index 00000000000..3ff2ea6b382
--- /dev/null
+++ b/src/devices/bus/adb/adb.cpp
@@ -0,0 +1,64 @@
+// license:BSD-3-Clause
+// copyright-holders: Olivier Galibert
+
+// ADB - Apple Desktop Bus
+//
+// The serial desktop device bus from before USB was cool.
+//
+// Single data wire + poweron line, open collector
+
+#include "emu.h"
+#include "adb.h"
+
+#include "adbhle.h"
+
+DEFINE_DEVICE_TYPE(ADB_CONNECTOR, adb_connector, "adbslot", "ADB connector")
+
+adb_connector::adb_connector(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+	device_t(mconfig, ADB_CONNECTOR, tag, owner, clock),
+	device_single_card_slot_interface<adb_slot_card_interface>(mconfig, *this)
+{
+}
+
+void adb_connector::device_start()
+{
+}
+
+adb_device *adb_connector::get_device()
+{
+	adb_slot_card_interface *const connected = get_card_device();
+	if (connected)
+		return connected->device().subdevice<adb_device>(connected->m_adb.finder_tag());
+	else
+		return nullptr;
+}
+
+adb_slot_card_interface::adb_slot_card_interface(const machine_config &mconfig, device_t &device, const char *adb_tag) :
+	device_interface(device, "adb"),
+	m_adb(*this, adb_tag)
+{
+}
+
+
+
+adb_device::adb_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock) :
+	device_t(mconfig, type, tag, owner, clock),
+	m_adb_cb(*this),
+	m_poweron_cb(*this)
+{
+}
+
+void adb_device::device_start()
+{
+}
+
+void adb_device::device_reset()
+{
+	m_adb_istate = true;
+	m_adb_ostate = true;
+}
+
+void adb_device::default_devices(device_slot_interface &device)
+{
+	device.option_add("hle", ADB_HLE);
+}
diff --git a/src/devices/bus/adb/adb.h b/src/devices/bus/adb/adb.h
new file mode 100644
index 00000000000..8a07986c531
--- /dev/null
+++ b/src/devices/bus/adb/adb.h
@@ -0,0 +1,73 @@
+// license:BSD-3-Clause
+// copyright-holders: Olivier Galibert
+
+// ADB - Apple Desktop Bus
+//
+// The serial desktop device bus from before USB was cool.
+//
+// Single data wire + poweron line, open collector
+
+#ifndef MAME_BUS_ADB_ADB_H
+#define MAME_BUS_ADB_ADB_H
+
+#pragma once
+
+class adb_device;
+class adb_slot_card_interface;
+
+class adb_connector: public device_t, public device_single_card_slot_interface<adb_slot_card_interface>
+{
+public:
+	template <typename T>
+	adb_connector(const machine_config &mconfig, const char *tag, device_t *owner, T &&opts, const char *dflt, bool fixed = false)
+		: adb_connector(mconfig, tag, owner, 0)
+	{
+		option_reset();
+		opts(*this);
+		set_default_option(dflt);
+		set_fixed(fixed);
+	}
+
+	adb_connector(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock = 0);
+	virtual ~adb_connector() = default;
+
+	adb_device *get_device();
+
+protected:
+	virtual void device_start() override;
+};
+
+class adb_slot_card_interface : public device_interface
+{
+	friend class adb_connector;
+
+public:
+	adb_slot_card_interface(const machine_config &mconfig, device_t &device, const char *adb_tag);
+
+private:
+	required_device<adb_device> m_adb;
+};
+
+class adb_device: public device_t
+{
+public:
+	virtual void adb_w(int state) = 0;
+	auto adb_r() { return m_adb_cb.bind(); }
+	auto poweron_r() { return m_poweron_cb.bind(); }
+
+	static void default_devices(device_slot_interface &device);
+
+protected:
+	adb_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, uint32_t clock);
+	virtual void device_start() override;
+	virtual void device_reset() override;
+
+private:
+	devcb_write_line m_adb_cb;
+	devcb_write_line m_poweron_cb;
+	bool m_adb_istate, m_adb_ostate;
+};
+
+DECLARE_DEVICE_TYPE(ADB_CONNECTOR, adb_connector)
+
+#endif
diff --git a/src/devices/bus/adb/adbhle.cpp b/src/devices/bus/adb/adbhle.cpp
new file mode 100644
index 00000000000..369595ef143
--- /dev/null
+++ b/src/devices/bus/adb/adbhle.cpp
@@ -0,0 +1,45 @@
+// license:BSD-3-Clause
+// copyright-holders: Olivier Galibert
+
+// ADB - Apple Desktop Bus
+//
+// Generic HLE
+
+#include "emu.h"
+#include "adbhle.h"
+
+DEFINE_DEVICE_TYPE(ADB_HLE, adb_hle_device, "adbhle", "ADB HLE")
+
+adb_hle_device::adb_hle_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock) :
+	adb_device(mconfig, ADB_HLE, tag, owner, clock),
+	adb_slot_card_interface(mconfig, *this, DEVICE_SELF)
+{
+}
+
+void adb_hle_device::device_start()
+{
+	adb_device::device_start();
+
+	save_item(NAME(m_last_state));
+	save_item(NAME(m_last_state_time));
+}
+
+void adb_hle_device::device_reset()
+{
+	adb_device::device_reset();
+	m_last_state = true;
+	m_last_state_time = machine().time();
+}
+
+void adb_hle_device::adb_w(int state)
+{
+	if(m_last_state != state) {
+		attotime delta = machine().time() - m_last_state_time;
+		u32 dt = delta.as_ticks(1000000);
+
+		logerror("level %d duration %6d us\n", m_last_state, dt);
+
+		m_last_state = state;
+		m_last_state_time = machine().time();
+	}
+}
diff --git a/src/devices/bus/adb/adbhle.h b/src/devices/bus/adb/adbhle.h
new file mode 100644
index 00000000000..24dff3ad2fe
--- /dev/null
+++ b/src/devices/bus/adb/adbhle.h
@@ -0,0 +1,33 @@
+// license:BSD-3-Clause
+// copyright-holders: Olivier Galibert
+
+// ADB - Apple Desktop Bus
+//
+// Generic HLE
+
+#ifndef MAME_BUS_ADB_ADBHLE_H
+#define MAME_BUS_ADB_ADBHLE_H
+
+#pragma once
+
+#include "adb.h"
+
+class adb_hle_device : public adb_device, public adb_slot_card_interface
+{
+public:
+	adb_hle_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
+
+protected:
+	virtual void device_start() override;
+	virtual void device_reset() override;
+
+	virtual void adb_w(int state) override;
+
+private:
+	bool m_last_state;
+	attotime m_last_state_time;
+};
+
+DECLARE_DEVICE_TYPE(ADB_HLE, adb_hle_device)
+
+#endif
diff --git a/src/mame/machine/egret.cpp b/src/mame/machine/egret.cpp
index b9056c215af..23148954c31 100644
--- a/src/mame/machine/egret.cpp
+++ b/src/mame/machine/egret.cpp
@@ -97,21 +97,49 @@ const tiny_rom_entry *egret_device::device_rom_region() const
 //**************************************************************************
 //  LIVE DEVICE
 //**************************************************************************
+#if USE_BUS_ADB
+void egret_device::adb_w(int id, int state)
+{
+	m_adb_device_out[id] = state;
+	adb_change();
+}
+
+void egret_device::adb_poweron_w(int id, int state)
+{
+	m_adb_device_poweron[id] = state;
+}
+
+void egret_device::adb_change()
+{
+	bool adb = m_adb_out & m_adb_device_out[0] & m_adb_device_out[1];
+	logerror("adb c:%d 1:%d 2:%d -> %d (%02x %02x)\n", m_adb_out, m_adb_device_out[0], m_adb_device_out[1], adb, ddrs[0], ports[0]);
+	for (int i = 0; i != 2; i++)
+		if (m_adb_device[i])
+		{
+			m_adb_device[i]->adb_w(adb);
+		}
+}
+#endif
 
 void egret_device::send_port(uint8_t offset, uint8_t data)
 {
 	switch (offset)
 	{
-		case 0: // port A
-/*          printf("ADB:%d DFAC:%d PowerEnable:%d\n",
+	case 0: // port A
+		/*          printf("ADB:%d DFAC:%d PowerEnable:%d\n",
                 (data & 0x80) ? 1 : 0,
                 (data & 0x10) ? 1 : 0,
                 (data & 0x02) ? 1 : 0);*/
 
-			if ((data & 0x80) != last_adb)
-			{
-				m_adb_dtime = (int)(machine().time().as_ticks(1000000) - last_adb_time);
-				/*
+#if USE_BUS_ADB
+		// the line goes to a mosfet pulling the adb data line to graound, hence the inversion
+		m_adb_out = !(data & 0x80);
+		adb_change();
+#else
+		if ((data & 0x80) != last_adb)
+		{
+			m_adb_dtime = (int)(machine().time().as_ticks(1000000) - last_adb_time);
+			/*
 				if (data & 0x80)
 				{
 				    printf("EG ADB: 1->0 time %d\n", m_adb_dtime);
@@ -121,14 +149,15 @@ void egret_device::send_port(uint8_t offset, uint8_t data)
 				    printf("EG ADB: 0->1 time %d\n", m_adb_dtime);
 				}
 				*/
-				// allow the linechange handler to override us
-				adb_in = (data & 0x80) ? true : false;
+			// allow the linechange handler to override us
+			adb_in = (data & 0x80) ? true : false;
 
-				write_linechange(((data & 0x80) >> 7) ^ 1);
+			write_linechange(((data & 0x80) >> 7) ^ 1);
 
-				last_adb = data & 0x80;
-				last_adb_time = machine().time().as_ticks(1000000);
+			last_adb = data & 0x80;
+			last_adb_time = machine().time().as_ticks(1000000);
 			}
+#endif
 			break;
 
 		case 1: // port B
@@ -205,8 +234,12 @@ uint8_t egret_device::ports_r(offs_t offset)
 	switch (offset)
 	{
 		case 0:     // port A
+#if USE_BUS_ADB
+			incoming |= (m_adb_out & m_adb_device_out[0] & m_adb_device_out[1]) ? 0x40 : 0;
+			incoming |= (m_adb_device_poweron[0] & m_adb_device_poweron[1]) ? 0x04 : 0;
+#else
 			incoming |= adb_in ? 0x40 : 0;
-
+#endif
 			if (egret_controls_power)
 			{
 				incoming |= 0x02;   // indicate soft power, indicate chassis switch on
@@ -327,12 +360,15 @@ void egret_device::pram_w(offs_t offset, uint8_t data)
 
 egret_device::egret_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock)
 	: device_t(mconfig, EGRET, tag, owner, clock),
-	device_nvram_interface(mconfig, *this),
-	write_reset(*this),
-	write_linechange(*this),
-	write_via_clock(*this),
-	write_via_data(*this),
-	m_maincpu(*this, EGRET_CPU_TAG)
+	  device_nvram_interface(mconfig, *this),
+	  write_reset(*this),
+	  write_linechange(*this),
+	  write_via_clock(*this),
+	  write_via_data(*this),
+	  m_maincpu(*this, EGRET_CPU_TAG)
+#if USE_BUS_ADB
+	, m_adb_connector{{*this, ":adb1"}, {*this, finder_base::DUMMY_TAG}}
+#endif
 {
 }
 
@@ -347,6 +383,18 @@ void egret_device::device_start()
 	write_via_clock.resolve_safe();
 	write_via_data.resolve_safe();
 
+#if USE_BUS_ADB
+	for (int i = 0; i < 2; i++)
+	{
+		m_adb_device[i] = m_adb_connector[i] ? m_adb_connector[i]->get_device() : nullptr;
+		if (m_adb_device[i])
+		{
+			m_adb_device[i]->adb_r().set([this, i](int state) { adb_w(i, state); });
+			m_adb_device[i]->poweron_r().set([this, i](int state) { adb_poweron_w(i, state); });
+		}
+	}
+#endif
+
 	m_timer = timer_alloc(0, nullptr);
 	save_item(NAME(ddrs[0]));
 	save_item(NAME(ddrs[1]));
@@ -369,6 +417,11 @@ void egret_device::device_start()
 	save_item(NAME(pram_loaded));
 	save_item(NAME(pram));
 	save_item(NAME(disk_pram));
+#if USE_BUS_ADB
+	save_item(NAME(m_adb_out));
+	save_item(NAME(m_adb_device_out));
+	save_item(NAME(m_adb_device_poweron));
+#endif
 
 	uint8_t *rom = device().machine().root_device().memregion(device().subtag(EGRET_CPU_TAG))->base();
 
@@ -388,6 +441,11 @@ void egret_device::device_reset()
 	ddrs[0] = ddrs[1] = ddrs[2] = 0;
 	ports[0] = ports[1] = ports[2] = 0;
 
+	#if USE_BUS_ADB
+	m_adb_device_out[0] = m_adb_device_out[1] = true;
+	m_adb_device_poweron[0] = m_adb_device_poweron[1] = true;
+	#endif
+
 	m_timer->adjust(attotime::never);
 
 	egret_controls_power = false;   // set to hard power control
diff --git a/src/mame/machine/egret.h b/src/mame/machine/egret.h
index b1597dca367..b4ea5882b0d 100644
--- a/src/mame/machine/egret.h
+++ b/src/mame/machine/egret.h
@@ -5,7 +5,11 @@
 
 #pragma once
 
+#define USE_BUS_ADB (0)
 
+#if USE_BUS_ADB
+#include "bus/adb/adb.h"
+#endif
 
 //**************************************************************************
 //  MACROS / CONSTANTS
@@ -59,6 +63,12 @@ public:
 	uint8_t pram_r(offs_t offset);
 	void pram_w(offs_t offset, uint8_t data);
 
+#if USE_BUS_ADB
+	void adb_w(int id, int state);
+	void adb_poweron_w(int id, int state);
+	void adb_change();
+#endif
+
 	// interface routines
 	uint8_t get_xcvr_session() { return xcvr_session; }
 	void set_via_full(uint8_t val) { via_full = val; }
@@ -107,6 +117,14 @@ private:
 	uint8_t pram[0x100], disk_pram[0x100];
 	bool pram_loaded;
 
+	#if USE_BUS_ADB
+	optional_device <adb_connector> m_adb_connector[2];
+	adb_device *m_adb_device[2];
+	bool m_adb_device_out[2];
+	bool m_adb_device_poweron[2];
+	bool m_adb_out;
+	#endif
+
 	void send_port(uint8_t offset, uint8_t data);
 };