diff --git a/src/devices/machine/m3002.cpp b/src/devices/machine/m3002.cpp
index 2416dc4afd6..8bb9edda2b9 100644
--- a/src/devices/machine/m3002.cpp
+++ b/src/devices/machine/m3002.cpp
@@ -7,13 +7,14 @@
     TODO:
     - Pulse output (256 Hz, second, minute, hour)
     - Test mode
+    - Emulate M 3000 differences (if any meaningful ones exist)
 
 **********************************************************************/
 
 #include "emu.h"
 #include "m3002.h"
 
-#define VERBOSE 1
+#define VERBOSE 0
 #include "logmacro.h"
 
 //**************************************************************************
@@ -21,6 +22,7 @@
 //**************************************************************************
 
 DEFINE_DEVICE_TYPE(M3002, m3002_device, "m3002", "EM M 3002 Real Time Clock")
+DEFINE_DEVICE_TYPE(M3000, m3000_device, "m3000", "EM M 3000 Real Time Clock")
 
 //**************************************************************************
 //  DEVICE CONSTRUCTION AND INITIALIZATION
@@ -32,8 +34,8 @@ ALLOW_SAVE_TYPE(m3002_device::mux_state);
 //  m3002_device - constructor
 //-------------------------------------------------
 
-m3002_device::m3002_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
-	: device_t(mconfig, M3002, tag, owner, clock)
+m3002_device::m3002_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock)
+	: device_t(mconfig, type, tag, owner, clock)
 	, device_nvram_interface(mconfig, *this)
 	, device_rtc_interface(mconfig, *this)
 	, m_irq_callback(*this)
@@ -46,6 +48,21 @@ m3002_device::m3002_device(const machine_config &mconfig, const char *tag, devic
 	std::fill_n(&m_ram[0], 0x10, 0);
 }
 
+m3002_device::m3002_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
+	: m3002_device(mconfig, M3002, tag, owner, clock)
+{
+}
+
+
+//-------------------------------------------------
+//  m3000_device - constructor
+//-------------------------------------------------
+
+m3000_device::m3000_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock)
+	: m3002_device(mconfig, M3000, tag, owner, clock)
+{
+}
+
 
 //-------------------------------------------------
 //  device_resolve_objects - resolve objects that
diff --git a/src/devices/machine/m3002.h b/src/devices/machine/m3002.h
index d75d5e99c70..d39f904fe60 100644
--- a/src/devices/machine/m3002.h
+++ b/src/devices/machine/m3002.h
@@ -46,6 +46,8 @@ public:
 	DECLARE_READ_LINE_MEMBER(irq_r) { return m_irq_active ? 0 : 1; }
 
 protected:
+	m3002_device(const machine_config &mconfig, device_type type, const char *tag, device_t *owner, u32 clock);
+
 	// device-level overrides
 	virtual void device_resolve_objects() override;
 	virtual void device_start() override;
@@ -95,7 +97,17 @@ private:
 	emu_timer *m_second_timer;
 };
 
-// device type declaration
+// ======================> m3000_device
+
+class m3000_device : public m3002_device
+{
+public:
+	// device type constructor
+	m3000_device(const machine_config &mconfig, const char *tag, device_t *owner, u32 clock);
+};
+
+// device type declarations
 DECLARE_DEVICE_TYPE(M3002, m3002_device)
+DECLARE_DEVICE_TYPE(M3000, m3000_device)
 
 #endif // MAME_MACHINE_M3002_H
diff --git a/src/mame/drivers/clxvme186.cpp b/src/mame/drivers/clxvme186.cpp
index 1594c6bdd80..ec3fdc68bb6 100644
--- a/src/mame/drivers/clxvme186.cpp
+++ b/src/mame/drivers/clxvme186.cpp
@@ -10,7 +10,7 @@
 #include "cpu/i86/i186.h"
 //#include "bus/vme/vme.h"
 #include "machine/74259.h"
-//#include "machine/m3000.h"
+#include "machine/m3002.h"
 #include "machine/z80scc.h"
 
 class clxvme186_state : public driver_device
@@ -65,7 +65,7 @@ void clxvme186_state::io_map(address_map &map)
 {
 	map(0xe000, 0xe001).unmaprw(); // SASI data port (PCS0)
 	map(0xe080, 0xe087).rw("scc", FUNC(scc8530_device::ab_dc_r), FUNC(scc8530_device::ab_dc_w)).umask16(0x00ff); // Serial I/O ports A & B (PCS1)
-	//map(0xe100, 0xe100).rw("rtc", FUNC(m3000_device::read), FUNC(m3000_device::write)); // Real time clock (PCS2)
+	map(0xe100, 0xe100).rw("rtc", FUNC(m3000_device::read), FUNC(m3000_device::write)); // Real time clock (PCS2)
 	map(0xe180, 0xe181).portr("TTL"); // TTL input port (PCS3)
 	map(0xe180, 0xe181).w(FUNC(clxvme186_state::unknown_w));
 	map(0xe190, 0xe190).r(FUNC(clxvme186_state::sasi_status_r)); // SASI status port (PCS3)
@@ -85,7 +85,7 @@ static INPUT_PORTS_START(clxvme186)
 	PORT_BIT(0x0020, IP_ACTIVE_LOW, IPT_UNKNOWN) // Printer busy
 	PORT_BIT(0x0040, IP_ACTIVE_LOW, IPT_UNKNOWN) // Printer paper empty
 	PORT_BIT(0x0080, IP_ACTIVE_LOW, IPT_UNKNOWN) // /SYSFAIL
-	PORT_BIT(0x0100, IP_ACTIVE_LOW, IPT_UNKNOWN) // Real time clock busy
+	PORT_BIT(0x0100, IP_ACTIVE_HIGH, IPT_CUSTOM) PORT_READ_LINE_DEVICE_MEMBER("rtc", m3000_device, busy_r)
 	PORT_BIT(0x0200, IP_ACTIVE_LOW, IPT_UNKNOWN) // Colex use only
 	PORT_BIT(0x0400, IP_ACTIVE_LOW, IPT_UNKNOWN) // Colex use only
 	PORT_BIT(0x0800, IP_ACTIVE_LOW, IPT_UNKNOWN) // /ACFAIL
@@ -102,7 +102,7 @@ void clxvme186_state::clxvme186(machine_config &config)
 
 	SCC8530N(config, "scc", 3.6864_MHz_XTAL);
 
-	//M3000(config, "rtc", 32.768_kHz_XTAL);
+	M3000(config, "rtc", 32.768_kHz_XTAL);
 
 	LS259(config, "ctrllatch");
 }
diff --git a/src/mame/drivers/cms.cpp b/src/mame/drivers/cms.cpp
index 0314d7cf58a..1c093c1bb64 100644
--- a/src/mame/drivers/cms.cpp
+++ b/src/mame/drivers/cms.cpp
@@ -167,7 +167,7 @@ void cms_state::cms6502(machine_config &config)
 	VIA6522(config, m_via, 1_MHz_XTAL);
 	m_via->irq_handler().set("irqs", FUNC(input_merger_device::in_w<0>));
 
-	M3002(config, "rtc", 32768);
+	M3002(config, "rtc", 32.768_kHz_XTAL);
 
 	/* 7 Slot Backplane */
 	ACORN_BUS(config, m_bus, 0);