diff --git a/src/raspberrypi/devices/block_device.h b/src/raspberrypi/devices/block_device.h
index ef0b69db..8511c227 100644
--- a/src/raspberrypi/devices/block_device.h
+++ b/src/raspberrypi/devices/block_device.h
@@ -11,22 +11,19 @@
 
 #pragma once
 
-#include "primary_device.h"
-
 class SASIDEV;
 
-// TODO There should also be MMCDevice, and scsicd should be derived from MMCDevice, not from BlockDevice
-class BlockDevice : public PrimaryDevice
+class BlockDevice
 {
 public:
 
-	BlockDevice(const string& id) : PrimaryDevice(id) {};
+	BlockDevice() {};
 	virtual ~BlockDevice() {};
 
 	// Mandatory commands
-	virtual void TestUnitReady(SASIDEV *) override = 0;
-	virtual void Inquiry(SASIDEV *) override = 0;
-	virtual void ReportLuns(SASIDEV *) override = 0;
+	virtual void TestUnitReady(SASIDEV *) = 0;
+	virtual void Inquiry(SASIDEV *) = 0;
+	virtual void ReportLuns(SASIDEV *) = 0;
 	virtual void FormatUnit(SASIDEV *) = 0;
 	virtual void ReadCapacity10(SASIDEV *) = 0;
 	virtual void ReadCapacity16(SASIDEV *) = 0;
@@ -34,15 +31,15 @@ public:
 	virtual void Read16(SASIDEV *) = 0;
 	virtual void Write10(SASIDEV *) = 0;
 	virtual void Write16(SASIDEV *) = 0;
-	virtual void RequestSense(SASIDEV *) override = 0;
+	virtual void RequestSense(SASIDEV *) = 0;
 
 	// Implemented optional commands
 	virtual void Verify10(SASIDEV *) = 0;
 	virtual void Verify16(SASIDEV *) = 0;
-	virtual void ModeSense(SASIDEV *) override = 0;
-	virtual void ModeSense10(SASIDEV *) override = 0;
-	virtual void ModeSelect(SASIDEV *) override = 0;
-	virtual void ModeSelect10(SASIDEV *) override = 0;
+	virtual void ModeSense(SASIDEV *) = 0;
+	virtual void ModeSense10(SASIDEV *) = 0;
+	virtual void ModeSelect(SASIDEV *) = 0;
+	virtual void ModeSelect10(SASIDEV *) = 0;
 	virtual void ReassignBlocks(SASIDEV *) = 0;
 	virtual void SendDiagnostic(SASIDEV *) = 0;
 	virtual void StartStopUnit(SASIDEV *) = 0;
diff --git a/src/raspberrypi/devices/disk.cpp b/src/raspberrypi/devices/disk.cpp
index 2202b253..6be32bb2 100644
--- a/src/raspberrypi/devices/disk.cpp
+++ b/src/raspberrypi/devices/disk.cpp
@@ -1076,7 +1076,7 @@ void DiskCache::Update()
 //	Constructor
 //
 //---------------------------------------------------------------------------
-Disk::Disk(const std::string id) : BlockDevice(id)
+Disk::Disk(const std::string id) : Device(id), PrimaryDevice(), BlockDevice()
 {
 	// Work initialization
 	sector_size_configurable = false;
@@ -1211,7 +1211,7 @@ void Disk::Open(const Filepath& path)
 //---------------------------------------------------------------------------
 bool Disk::Eject(bool force)
 {
-	bool status = BlockDevice::Eject(force);
+	bool status = Device::Eject(force);
 	if (status) {
 		// Remove disk cache
 		disk.dcache->Save();
diff --git a/src/raspberrypi/devices/disk.h b/src/raspberrypi/devices/disk.h
index 5a0953b2..c7110db2 100644
--- a/src/raspberrypi/devices/disk.h
+++ b/src/raspberrypi/devices/disk.h
@@ -21,7 +21,9 @@
 #include "log.h"
 #include "scsi.h"
 #include "controllers/scsidev_ctrl.h"
+#include "primary_device.h"
 #include "block_device.h"
+#include "device.h"
 #include "file_support.h"
 #include "filepath.h"
 #include <string>
@@ -124,7 +126,7 @@ private:
 //	Disk
 //
 //===========================================================================
-class Disk : public BlockDevice
+class Disk : public Device, public PrimaryDevice, public BlockDevice
 {
 private:
 	enum access_mode { RW6, RW10, RW16 };
diff --git a/src/raspberrypi/devices/mmc_device.h b/src/raspberrypi/devices/mmc_device.h
new file mode 100644
index 00000000..deff28d4
--- /dev/null
+++ b/src/raspberrypi/devices/mmc_device.h
@@ -0,0 +1,25 @@
+//---------------------------------------------------------------------------
+//
+// SCSI Target Emulator RaSCSI (*^..^*)
+// for Raspberry Pi
+//
+// Copyright (C) 2021 Uwe Seimet
+//
+// An MmcDevice supports SCSI MMC commands (see https://www.t10.org/drafts.htm, MMC-6)
+//
+//---------------------------------------------------------------------------
+
+#pragma once
+
+class SASIDEV;
+
+class MmcDevice
+{
+public:
+
+	MmcDevice() {};
+	virtual ~MmcDevice() {};
+
+	virtual void ReadToc(SASIDEV *) = 0;
+	virtual void GetEventStatusNotification(SASIDEV *) = 0;
+};
diff --git a/src/raspberrypi/devices/primary_device.h b/src/raspberrypi/devices/primary_device.h
index 412cd109..7909940e 100644
--- a/src/raspberrypi/devices/primary_device.h
+++ b/src/raspberrypi/devices/primary_device.h
@@ -11,15 +11,13 @@
 
 #pragma once
 
-#include "device.h"
-
 class SASIDEV;
 
-class PrimaryDevice : public Device
+class PrimaryDevice
 {
 public:
 
-	PrimaryDevice(const string& id) : Device(id) {};
+	PrimaryDevice() {};
 	virtual ~PrimaryDevice() {};
 
 	// Mandatory commands
diff --git a/src/raspberrypi/devices/scsicd.cpp b/src/raspberrypi/devices/scsicd.cpp
index 024fe4db..f4bdb80b 100644
--- a/src/raspberrypi/devices/scsicd.cpp
+++ b/src/raspberrypi/devices/scsicd.cpp
@@ -224,7 +224,7 @@ bool CDTrack::IsAudio() const
 //	Constructor
 //
 //---------------------------------------------------------------------------
-SCSICD::SCSICD() : Disk("SCCD")
+SCSICD::SCSICD() : Disk("SCCD"), MmcDevice(), FileSupport()
 {
 	SetRemovable(true);
 	SetReadOnly(true);
diff --git a/src/raspberrypi/devices/scsicd.h b/src/raspberrypi/devices/scsicd.h
index dc2c33ca..196e10a3 100644
--- a/src/raspberrypi/devices/scsicd.h
+++ b/src/raspberrypi/devices/scsicd.h
@@ -16,6 +16,8 @@
 #pragma once
 
 #include "os.h"
+#include "primary_device.h"
+#include "mmc_device.h"
 #include "disk.h"
 #include "filepath.h"
 
@@ -67,7 +69,7 @@ private:
 //	SCSI CD-ROM
 //
 //===========================================================================
-class SCSICD : public Disk, public FileSupport
+class SCSICD : public Disk, public MmcDevice, public FileSupport
 {
 private:
 	typedef struct _command_t {