diff --git a/src/raspberrypi/rascsi.h b/src/raspberrypi/config.h
similarity index 100%
rename from src/raspberrypi/rascsi.h
rename to src/raspberrypi/config.h
diff --git a/src/raspberrypi/controllers/sasidev_ctrl.h b/src/raspberrypi/controllers/sasidev_ctrl.h
index 9e790270..719bfc73 100644
--- a/src/raspberrypi/controllers/sasidev_ctrl.h
+++ b/src/raspberrypi/controllers/sasidev_ctrl.h
@@ -15,7 +15,7 @@
 //---------------------------------------------------------------------------
 #pragma once
 
-#include "../rascsi.h"
+#include "../config.h"
 #include "os.h"
 #include "scsi.h"
 #include "fileio.h"
diff --git a/src/raspberrypi/controllers/scsidev_ctrl.cpp b/src/raspberrypi/controllers/scsidev_ctrl.cpp
index f85d9f3d..8fb8952e 100644
--- a/src/raspberrypi/controllers/scsidev_ctrl.cpp
+++ b/src/raspberrypi/controllers/scsidev_ctrl.cpp
@@ -17,7 +17,6 @@
 #include "controllers/scsidev_ctrl.h"
 #include "gpiobus.h"
 #include "devices/scsi_daynaport.h"
-#include <sstream>
 
 //===========================================================================
 //
@@ -239,7 +238,7 @@ void SCSIDEV::Execute()
 	ctrl.execstart = SysTimer::GetTimerLow();
 
 	// Discard pending sense data from the previous command if the current command is not REQUEST SENSE
-	if ((ScsiDefs::scsi_command)ctrl.cmd[0] != ScsiDefs::eCmdRequestSense) {
+	if ((scsi_defs::scsi_command)ctrl.cmd[0] != scsi_defs::eCmdRequestSense) {
 		ctrl.status = 0;
 	}
 
@@ -247,8 +246,8 @@ void SCSIDEV::Execute()
 
 	int lun = GetEffectiveLun();
 	if (!ctrl.unit[lun]) {
-		if ((ScsiDefs::scsi_command)ctrl.cmd[0] != ScsiDefs::eCmdInquiry &&
-				(ScsiDefs::scsi_command)ctrl.cmd[0] != ScsiDefs::eCmdRequestSense) {
+		if ((scsi_defs::scsi_command)ctrl.cmd[0] != scsi_defs::eCmdInquiry &&
+				(scsi_defs::scsi_command)ctrl.cmd[0] != scsi_defs::eCmdRequestSense) {
 			LOGDEBUG("Invalid LUN %d for ID %d", lun, GetSCSIID());
 
 			Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::INVALID_LUN);
@@ -266,7 +265,7 @@ void SCSIDEV::Execute()
 	ctrl.device = ctrl.unit[lun];
 
 	// Discard pending sense data from the previous command if the current command is not REQUEST SENSE
-	if ((ScsiDefs::scsi_command)ctrl.cmd[0] != ScsiDefs::eCmdRequestSense) {
+	if ((scsi_defs::scsi_command)ctrl.cmd[0] != scsi_defs::eCmdRequestSense) {
 		ctrl.device->SetStatusCode(0);
 	}
 	
@@ -277,7 +276,7 @@ void SCSIDEV::Execute()
 	}
 
 	// SCSI-2 p.104 4.4.3 Incorrect logical unit handling
-	if ((ScsiDefs::scsi_command)ctrl.cmd[0] == ScsiDefs::eCmdInquiry && !ctrl.unit[lun]) {
+	if ((scsi_defs::scsi_command)ctrl.cmd[0] == scsi_defs::eCmdInquiry && !ctrl.unit[lun]) {
 		lun = GetEffectiveLun();
 
 		LOGTRACE("Reporting LUN %d for device ID %d as not supported", lun, ctrl.device->GetId());
@@ -381,9 +380,8 @@ void SCSIDEV::Send()
 
 	//if Length! = 0, send
 	if (ctrl.length != 0) {
-		ostringstream s;
-		s << __PRETTY_FUNCTION__ << " sending handhake with offset " << ctrl.offset << ", length " << ctrl.length;
-		LOGTRACE("%s", s.str().c_str());
+		LOGTRACE("%s%s", __PRETTY_FUNCTION__, (" Sending handhake with offset " + to_string(ctrl.offset) + ", length "
+				+ to_string(ctrl.length)).c_str());
 
 		// TODO Get rid of Daynaport specific code in this class
 		// The Daynaport needs to have a delay after the size/flags field
@@ -420,9 +418,7 @@ void SCSIDEV::Send()
 		if (ctrl.blocks != 0) {
 			// set next buffer (set offset, length)
 			result = XferIn(ctrl.buffer);
-			ostringstream s;
-			s << __PRETTY_FUNCTION__ << " Processing after data collection. Blocks: " << ctrl.blocks;
-			LOGTRACE("%s", s.str().c_str());
+			LOGTRACE("%s%s", __PRETTY_FUNCTION__, (" Processing after data collection. Blocks: " + to_string(ctrl.blocks)).c_str());
 		}
 	}
 
@@ -434,9 +430,7 @@ void SCSIDEV::Send()
 
 	// Continue sending if block !=0
 	if (ctrl.blocks != 0){
-		ostringstream s;
-		s << __PRETTY_FUNCTION__ << " Continuing to send. Blocks: " << ctrl.blocks;
-		LOGTRACE("%s", s.str().c_str());
+		LOGTRACE("%s%s", __PRETTY_FUNCTION__, (" Continuing to send. Blocks: " + to_string(ctrl.blocks)).c_str());
 		ASSERT(ctrl.length > 0);
 		ASSERT(ctrl.offset == 0);
 		return;
diff --git a/src/raspberrypi/devices/device.cpp b/src/raspberrypi/devices/device.cpp
index 31e75fa2..8e194967 100644
--- a/src/raspberrypi/devices/device.cpp
+++ b/src/raspberrypi/devices/device.cpp
@@ -8,17 +8,20 @@
 //---------------------------------------------------------------------------
 
 #include <cassert>
-#include <sstream>
 #include "rascsi_version.h"
 #include "os.h"
 #include "log.h"
 #include "exceptions.h"
 #include "device.h"
 
+set<Device *> Device::devices;
+
 Device::Device(const string& type)
 {
 	assert(type.length() == 4);
 
+	devices.insert(this);
+
 	this->type = type;
 
 	vendor = DEFAULT_VENDOR;
@@ -48,6 +51,11 @@ Device::Device(const string& type)
 	status_code = STATUS_NOERROR;
 }
 
+Device::~Device()
+{
+	devices.erase(this);
+}
+
 void Device::Reset()
 {
 	locked = false;
diff --git a/src/raspberrypi/devices/device.h b/src/raspberrypi/devices/device.h
index 621ac06e..3978eec0 100644
--- a/src/raspberrypi/devices/device.h
+++ b/src/raspberrypi/devices/device.h
@@ -9,6 +9,7 @@
 
 #pragma once
 
+#include <set>
 #include <map>
 #include <string>
 
@@ -104,10 +105,14 @@ private:
 	// Sense Key, ASC and ASCQ
 	int status_code;
 
+protected:
+
+	static set<Device *> devices;
+
 public:
 
 	Device(const string&);
-	virtual ~Device() {};
+	virtual ~Device();
 
 	// Override for device specific initializations, to be called after all device properties have been set
 	virtual bool Init(const map<string, string>&) { return true; };
diff --git a/src/raspberrypi/devices/disk.cpp b/src/raspberrypi/devices/disk.cpp
index 44888408..0585ce44 100644
--- a/src/raspberrypi/devices/disk.cpp
+++ b/src/raspberrypi/devices/disk.cpp
@@ -20,12 +20,11 @@
 #include "exceptions.h"
 #include "disk.h"
 #include "mode_page_device.h"
-#include <sstream>
 
-Disk::Disk(const std::string id) : ModePageDevice(id), ScsiBlockCommands()
+using namespace scsi_defs;
+
+Disk::Disk(const string& id) : ModePageDevice(id), ScsiBlockCommands()
 {
-	disks.insert(this);
-
 	// Work initialization
 	configured_sector_size = 0;
 	disk.size = 0;
@@ -33,34 +32,34 @@ Disk::Disk(const std::string id) : ModePageDevice(id), ScsiBlockCommands()
 	disk.dcache = NULL;
 	disk.image_offset = 0;
 
-	AddCommand(ScsiDefs::eCmdRezero, "Rezero", &Disk::Rezero);
-	AddCommand(ScsiDefs::eCmdFormat, "FormatUnit", &Disk::FormatUnit);
-	AddCommand(ScsiDefs::eCmdReassign, "ReassignBlocks", &Disk::ReassignBlocks);
-	AddCommand(ScsiDefs::eCmdRead6, "Read6", &Disk::Read6);
-	AddCommand(ScsiDefs::eCmdWrite6, "Write6", &Disk::Write6);
-	AddCommand(ScsiDefs::eCmdSeek6, "Seek6", &Disk::Seek6);
-	AddCommand(ScsiDefs::eCmdReserve6, "Reserve6", &Disk::Reserve6);
-	AddCommand(ScsiDefs::eCmdRelease6, "Release6", &Disk::Release6);
-	AddCommand(ScsiDefs::eCmdStartStop, "StartStopUnit", &Disk::StartStopUnit);
-	AddCommand(ScsiDefs::eCmdSendDiag, "SendDiagnostic", &Disk::SendDiagnostic);
-	AddCommand(ScsiDefs::eCmdRemoval, "PreventAllowMediumRemoval", &Disk::PreventAllowMediumRemoval);
-	AddCommand(ScsiDefs::eCmdReadCapacity10, "ReadCapacity10", &Disk::ReadCapacity10);
-	AddCommand(ScsiDefs::eCmdRead10, "Read10", &Disk::Read10);
-	AddCommand(ScsiDefs::eCmdWrite10, "Write10", &Disk::Write10);
-	AddCommand(ScsiDefs::eCmdReadLong10, "ReadLong10", &Disk::ReadLong10);
-	AddCommand(ScsiDefs::eCmdWriteLong10, "WriteLong10", &Disk::WriteLong10);
-	AddCommand(ScsiDefs::eCmdWriteLong16, "WriteLong16", &Disk::WriteLong16);
-	AddCommand(ScsiDefs::eCmdSeek10, "Seek10", &Disk::Seek10);
-	AddCommand(ScsiDefs::eCmdVerify10, "Verify10", &Disk::Verify10);
-	AddCommand(ScsiDefs::eCmdSynchronizeCache10, "SynchronizeCache10", &Disk::SynchronizeCache10);
-	AddCommand(ScsiDefs::eCmdSynchronizeCache16, "SynchronizeCache16", &Disk::SynchronizeCache16);
-	AddCommand(ScsiDefs::eCmdReadDefectData10, "ReadDefectData10", &Disk::ReadDefectData10);
-	AddCommand(ScsiDefs::eCmdReserve10, "Reserve10", &Disk::Reserve10);
-	AddCommand(ScsiDefs::eCmdRelease10, "Release10", &Disk::Release10);
-	AddCommand(ScsiDefs::eCmdRead16, "Read16", &Disk::Read16);
-	AddCommand(ScsiDefs::eCmdWrite16, "Write16", &Disk::Write16);
-	AddCommand(ScsiDefs::eCmdVerify16, "Verify16", &Disk::Verify16);
-	AddCommand(ScsiDefs::eCmdReadCapacity16_ReadLong16, "ReadCapacity16/ReadLong16", &Disk::ReadCapacity16_ReadLong16);
+	dispatcher.AddCommand(eCmdRezero, "Rezero", &Disk::Rezero);
+	dispatcher.AddCommand(eCmdFormat, "FormatUnit", &Disk::FormatUnit);
+	dispatcher.AddCommand(eCmdReassign, "ReassignBlocks", &Disk::ReassignBlocks);
+	dispatcher.AddCommand(eCmdRead6, "Read6", &Disk::Read6);
+	dispatcher.AddCommand(eCmdWrite6, "Write6", &Disk::Write6);
+	dispatcher.AddCommand(eCmdSeek6, "Seek6", &Disk::Seek6);
+	dispatcher.AddCommand(eCmdReserve6, "Reserve6", &Disk::Reserve6);
+	dispatcher.AddCommand(eCmdRelease6, "Release6", &Disk::Release6);
+	dispatcher.AddCommand(eCmdStartStop, "StartStopUnit", &Disk::StartStopUnit);
+	dispatcher.AddCommand(eCmdSendDiag, "SendDiagnostic", &Disk::SendDiagnostic);
+	dispatcher.AddCommand(eCmdRemoval, "PreventAllowMediumRemoval", &Disk::PreventAllowMediumRemoval);
+	dispatcher.AddCommand(eCmdReadCapacity10, "ReadCapacity10", &Disk::ReadCapacity10);
+	dispatcher.AddCommand(eCmdRead10, "Read10", &Disk::Read10);
+	dispatcher.AddCommand(eCmdWrite10, "Write10", &Disk::Write10);
+	dispatcher.AddCommand(eCmdReadLong10, "ReadLong10", &Disk::ReadLong10);
+	dispatcher.AddCommand(eCmdWriteLong10, "WriteLong10", &Disk::WriteLong10);
+	dispatcher.AddCommand(eCmdWriteLong16, "WriteLong16", &Disk::WriteLong16);
+	dispatcher.AddCommand(eCmdSeek10, "Seek10", &Disk::Seek10);
+	dispatcher.AddCommand(eCmdVerify10, "Verify10", &Disk::Verify10);
+	dispatcher.AddCommand(eCmdSynchronizeCache10, "SynchronizeCache10", &Disk::SynchronizeCache10);
+	dispatcher.AddCommand(eCmdSynchronizeCache16, "SynchronizeCache16", &Disk::SynchronizeCache16);
+	dispatcher.AddCommand(eCmdReadDefectData10, "ReadDefectData10", &Disk::ReadDefectData10);
+	dispatcher.AddCommand(eCmdReserve10, "Reserve10", &Disk::Reserve10);
+	dispatcher.AddCommand(eCmdRelease10, "Release10", &Disk::Release10);
+	dispatcher.AddCommand(eCmdRead16, "Read16", &Disk::Read16);
+	dispatcher.AddCommand(eCmdWrite16, "Write16", &Disk::Write16);
+	dispatcher.AddCommand(eCmdVerify16, "Verify16", &Disk::Verify16);
+	dispatcher.AddCommand(eCmdReadCapacity16_ReadLong16, "ReadCapacity16/ReadLong16", &Disk::ReadCapacity16_ReadLong16);
 }
 
 Disk::~Disk()
@@ -78,37 +77,12 @@ Disk::~Disk()
 		delete disk.dcache;
 		disk.dcache = NULL;
 	}
-
-	for (auto const& command : commands) {
-		delete command.second;
-	}
-
-	disks.erase(this);
-}
-
-void Disk::AddCommand(ScsiDefs::scsi_command opcode, const char* name, void (Disk::*execute)(SASIDEV *))
-{
-	commands[opcode] = new command_t(name, execute);
 }
 
 bool Disk::Dispatch(SCSIDEV *controller)
 {
-	ctrl = controller->GetCtrl();
-
-	if (commands.count(static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0]))) {
-		command_t *command = commands[static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0])];
-
-		LOGDEBUG("%s Executing %s ($%02X)", __PRETTY_FUNCTION__, command->name, (unsigned int)ctrl->cmd[0]);
-
-		(this->*command->execute)(controller);
-
-		return true;
-	}
-
-	LOGTRACE("%s Calling base class for dispatching $%02X", __PRETTY_FUNCTION__, (unsigned int)ctrl->cmd[0]);
-
-	// The base class handles the less specific commands
-	return ModePageDevice::Dispatch(controller);
+	// The superclass handles the less specific commands
+	return dispatcher.Dispatch(this, controller) ? true : super::Dispatch(controller);
 }
 
 //---------------------------------------------------------------------------
@@ -1276,9 +1250,8 @@ bool Disk::CheckBlockAddress(SASIDEV *controller, access_mode mode)
 
 	uint64_t capacity = GetBlockCount();
 	if (block > capacity) {
-		ostringstream s;
-		s << "Capacity of " << capacity << " blocks exceeded: " << "Trying to access block " << block;
-		LOGTRACE("%s", s.str().c_str());
+		LOGTRACE("%s", ("Capacity of " + to_string(capacity) + " blocks exceeded: Trying to access block "
+				+ to_string(block)).c_str());
 		controller->Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::LBA_OUT_OF_RANGE);
 		return false;
 	}
@@ -1339,10 +1312,8 @@ bool Disk::GetStartAndCount(SASIDEV *controller, uint64_t& start, uint32_t& coun
 	// Check capacity
 	uint64_t capacity = GetBlockCount();
 	if (start > capacity || start + count > capacity) {
-		ostringstream s;
-		s << "Capacity of " << capacity << " blocks exceeded: "
-				<< "Trying to read block " << start << ", block count " << ctrl->blocks;
-		LOGTRACE("%s", s.str().c_str());
+		LOGTRACE("%s", ("Capacity of " + to_string(capacity) + " blocks exceeded: Trying to access block "
+				+ to_string(start) + ", block count " + to_string(ctrl->blocks)).c_str());
 		controller->Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::LBA_OUT_OF_RANGE);
 		return false;
 	}
@@ -1366,9 +1337,7 @@ void Disk::SetSectorSizeInBytes(uint32_t size, bool sasi)
 {
 	set<uint32_t> sector_sizes = DeviceFactory::instance().GetSectorSizes(GetType());
 	if (!sector_sizes.empty() && sector_sizes.find(size) == sector_sizes.end()) {
-		stringstream error;
-		error << "Invalid block size of " << size << " bytes";
-		throw io_exception(error.str());
+		throw io_exception("Invalid block size of " + to_string(size) + " bytes");
 	}
 
 	switch (size) {
diff --git a/src/raspberrypi/devices/disk.h b/src/raspberrypi/devices/disk.h
index 68b06dcd..59bdb740 100644
--- a/src/raspberrypi/devices/disk.h
+++ b/src/raspberrypi/devices/disk.h
@@ -26,12 +26,13 @@
 #include "file_support.h"
 #include "filepath.h"
 #include "interfaces/scsi_block_commands.h"
-#include "interfaces/scsi_primary_commands.h"
 #include "mode_page_device.h"
 #include <string>
 #include <set>
 #include <map>
 
+using namespace std;
+
 class Disk : public ModePageDevice, ScsiBlockCommands
 {
 private:
@@ -52,18 +53,10 @@ private:
 		off_t image_offset;						// Offset to actual data
 	} disk_t;
 
-	typedef struct _command_t {
-		const char* name;
-		void (Disk::*execute)(SASIDEV *);
-
-		_command_t(const char* _name, void (Disk::*_execute)(SASIDEV *)) : name(_name), execute(_execute) { };
-	} command_t;
-	std::map<ScsiDefs::scsi_command, command_t*> commands;
-
-	void AddCommand(ScsiDefs::scsi_command, const char*, void (Disk::*)(SASIDEV *));
+	Dispatcher<Disk> dispatcher;
 
 public:
-	Disk(std::string);
+	Disk(const string&);
 	virtual ~Disk();
 
 	virtual bool Dispatch(SCSIDEV *) override;
@@ -76,13 +69,14 @@ public:
 	bool Eject(bool) override;
 
 private:
+	typedef ModePageDevice super;
 
 	// Commands covered by the SCSI specification (see https://www.t10.org/drafts.htm)
-	void StartStopUnit(SASIDEV *) override;
-	void SendDiagnostic(SASIDEV *) override;
+	void StartStopUnit(SASIDEV *);
+	void SendDiagnostic(SASIDEV *);
 	void PreventAllowMediumRemoval(SASIDEV *);
-	void SynchronizeCache10(SASIDEV *) override;
-	void SynchronizeCache16(SASIDEV *) override;
+	void SynchronizeCache10(SASIDEV *);
+	void SynchronizeCache16(SASIDEV *);
 	void ReadDefectData10(SASIDEV *);
 	virtual void Read6(SASIDEV *);
 	void Read10(SASIDEV *) override;
@@ -90,12 +84,12 @@ private:
 	virtual void Write6(SASIDEV *);
 	void Write10(SASIDEV *) override;
 	void Write16(SASIDEV *) override;
-	void ReadLong10(SASIDEV *) override;
-	void ReadLong16(SASIDEV *) override;
-	void WriteLong10(SASIDEV *) override;
-	void WriteLong16(SASIDEV *) override;
-	void Verify10(SASIDEV *) override;
-	void Verify16(SASIDEV *) override;
+	void ReadLong10(SASIDEV *);
+	void ReadLong16(SASIDEV *);
+	void WriteLong10(SASIDEV *);
+	void WriteLong16(SASIDEV *);
+	void Verify10(SASIDEV *);
+	void Verify16(SASIDEV *);
 	void Seek(SASIDEV *);
 	void Seek10(SASIDEV *);
 	void ReadCapacity10(SASIDEV *) override;
@@ -110,7 +104,7 @@ public:
 	// Commands covered by the SCSI specification (see https://www.t10.org/drafts.htm)
 	void Rezero(SASIDEV *);
 	void FormatUnit(SASIDEV *) override;
-	void ReassignBlocks(SASIDEV *) override;
+	void ReassignBlocks(SASIDEV *);
 	void Seek6(SASIDEV *);
 
 	// Command helpers
@@ -154,8 +148,6 @@ protected:
 	// Internal disk data
 	disk_t disk;
 
-	set<Disk *> disks;
-
 private:
 	void Read(SASIDEV *, uint64_t);
 	void Write(SASIDEV *, uint64_t);
diff --git a/src/raspberrypi/devices/dispatcher.h b/src/raspberrypi/devices/dispatcher.h
new file mode 100644
index 00000000..6cd0cc47
--- /dev/null
+++ b/src/raspberrypi/devices/dispatcher.h
@@ -0,0 +1,67 @@
+//---------------------------------------------------------------------------
+//
+// SCSI Target Emulator RaSCSI (*^..^*)
+// for Raspberry Pi
+//
+// Copyright (C) 2022 Uwe Seimet
+//
+// A template for dispatching SCSI commands
+//
+//---------------------------------------------------------------------------
+
+#pragma once
+
+#include "log.h"
+#include "scsi.h"
+#include <map>
+
+class SASIDEV;
+class SCSIDEV;
+
+using namespace std;
+using namespace scsi_defs;
+
+template<class T>
+class Dispatcher
+{
+public:
+
+	Dispatcher() {}
+	~Dispatcher()
+	{
+		for (auto const& command : commands) {
+			delete command.second;
+		}
+	}
+
+	typedef struct _command_t {
+		const char* name;
+		void (T::*execute)(SASIDEV *);
+
+		_command_t(const char* _name, void (T::*_execute)(SASIDEV *)) : name(_name), execute(_execute) { };
+	} command_t;
+	map<scsi_command, command_t*> commands;
+
+	void AddCommand(scsi_command opcode, const char* name, void (T::*execute)(SASIDEV *))
+	{
+		commands[opcode] = new command_t(name, execute);
+	}
+
+	bool Dispatch(T *instance, SCSIDEV *controller)
+	{
+		SASIDEV::ctrl_t *ctrl = controller->GetCtrl();
+		instance->SetCtrl(ctrl);
+
+		const auto& it = commands.find(static_cast<scsi_command>(ctrl->cmd[0]));
+		if (it != commands.end()) {
+			LOGDEBUG("%s Executing %s ($%02X)", __PRETTY_FUNCTION__, it->second->name, (unsigned int)ctrl->cmd[0]);
+
+			(instance->*it->second->execute)(controller);
+
+			return true;
+		}
+
+		// Unknown command
+		return false;
+	}
+};
diff --git a/src/raspberrypi/devices/host_services.cpp b/src/raspberrypi/devices/host_services.cpp
index f4e3b6b6..b3b11f25 100644
--- a/src/raspberrypi/devices/host_services.cpp
+++ b/src/raspberrypi/devices/host_services.cpp
@@ -30,24 +30,20 @@
 //   b) !start && load (EJECT): Shut down the Raspberry Pi
 //
 
+#include "controllers/scsidev_ctrl.h"
 #include "host_services.h"
 
+using namespace scsi_defs;
+
+HostServices::HostServices() : ModePageDevice("SCHS")
+{
+	dispatcher.AddCommand(eCmdStartStop, "StartStopUnit", &HostServices::StartStopUnit);
+}
+
 bool HostServices::Dispatch(SCSIDEV *controller)
 {
-	unsigned int cmd = controller->GetCtrl()->cmd[0];
-
-	// Only certain commands are supported
-	// TODO Do not inherit from Disk, mode page handling should be moved to ModePageDevice
-	if (cmd == ScsiDefs::eCmdTestUnitReady || cmd == ScsiDefs::eCmdRequestSense
-			|| cmd == ScsiDefs::eCmdInquiry || cmd == ScsiDefs::eCmdReportLuns
-			|| cmd == ScsiDefs::eCmdModeSense6 || cmd == ScsiDefs::eCmdModeSense10
-			|| cmd == ScsiDefs::eCmdStartStop) {
-		LOGTRACE("%s Calling base class for dispatching $%02X", __PRETTY_FUNCTION__, cmd);
-
-		return Disk::Dispatch(controller);
-	}
-
-	return false;
+	// The superclass class handles the less specific commands
+	return dispatcher.Dispatch(this, controller) ? true : super::Dispatch(controller);
 }
 
 void HostServices::TestUnitReady(SASIDEV *controller)
@@ -58,28 +54,8 @@ void HostServices::TestUnitReady(SASIDEV *controller)
 
 int HostServices::Inquiry(const DWORD *cdb, BYTE *buf)
 {
-	int allocation_length = cdb[4] + (((DWORD)cdb[3]) << 8);
-	if (allocation_length > 4) {
-		if (allocation_length > 44) {
-			allocation_length = 44;
-		}
-
-		// Basic data
-		// buf[0] ... Processor Device
-		// buf[1] ... Not removable
-		// buf[2] ... SCSI-2 compliant command system
-		// buf[3] ... SCSI-2 compliant Inquiry response
-		// buf[4] ... Inquiry additional data
-		memset(buf, 0, allocation_length);
-		buf[0] = 0x03;
-		buf[2] = 0x01;
-		buf[4] = 0x1F;
-
-		// Padded vendor, product, revision
-		memcpy(&buf[8], GetPaddedName().c_str(), 28);
-	}
-
-	return allocation_length;
+	// Processor device, not removable
+	return PrimaryDevice::Inquiry(3, false, cdb, buf);
 }
 
 void HostServices::StartStopUnit(SASIDEV *controller)
@@ -88,10 +64,10 @@ void HostServices::StartStopUnit(SASIDEV *controller)
 	bool load = ctrl->cmd[4] & 0x02;
 
 	if (!start) {
-		// Delete all regular disk devices. This also flushes their caches.
-		for (auto disk : disks) {
-			if (disk && disk != this) {
-				delete disk;
+		// Delete all other devices. This will also flush any caches.
+		for (const Device *device : devices) {
+			if (device != this) {
+				delete device;
 			}
 		}
 
@@ -109,7 +85,91 @@ void HostServices::StartStopUnit(SASIDEV *controller)
 	controller->Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::INVALID_FIELD_IN_CDB);
 }
 
-int HostServices::AddVendorPage(int page, bool, BYTE *buf)
+int HostServices::ModeSense6(const DWORD *cdb, BYTE *buf)
+{
+	// Get length, clear buffer
+	int length = (int)cdb[4];
+	memset(buf, 0, length);
+
+	// Get page code (0x00 is valid from the beginning)
+	int page = cdb[2] & 0x3f;
+	bool valid = page == 0x00;
+
+	LOGTRACE("%s Requesting mode page $%02X", __PRETTY_FUNCTION__, page);
+
+	// Basic information
+	int size = 4;
+
+	int ret = AddRealtimeClockPage(page, &buf[size]);
+	if (ret > 0) {
+		size += ret;
+		valid = true;
+	}
+
+	if (!valid) {
+		LOGTRACE("%s Unsupported mode page $%02X", __PRETTY_FUNCTION__, page);
+		SetStatusCode(STATUS_INVALIDCDB);
+		return 0;
+	}
+
+	// Do not return more than ALLOCATION LENGTH bytes
+	if (size > length) {
+		LOGTRACE("%s %d bytes available, %d bytes requested", __PRETTY_FUNCTION__, size, length);
+		size = length;
+	}
+
+	// Final setting of mode data length
+	buf[0] = size;
+
+	return size;
+}
+
+int HostServices::ModeSense10(const DWORD *cdb, BYTE *buf)
+{
+	// Get length, clear buffer
+	int length = cdb[7];
+	length <<= 8;
+	length |= cdb[8];
+	if (length > 0x800) {
+		length = 0x800;
+	}
+	memset(buf, 0, length);
+
+	// Get page code (0x00 is valid from the beginning)
+	int page = cdb[2] & 0x3f;
+	bool valid = page == 0x00;
+
+	LOGTRACE("%s Requesting mode page $%02X", __PRETTY_FUNCTION__, page);
+
+	// Basic Information
+	int size = 8;
+
+	int ret = AddRealtimeClockPage(page, &buf[size]);
+	if (ret > 0) {
+		size += ret;
+		valid = true;
+	}
+
+	if (!valid) {
+		LOGTRACE("%s Unsupported mode page $%02X", __PRETTY_FUNCTION__, page);
+		SetStatusCode(STATUS_INVALIDCDB);
+		return 0;
+	}
+
+	// Do not return more than ALLOCATION LENGTH bytes
+	if (size > length) {
+		LOGTRACE("%s %d bytes available, %d bytes requested", __PRETTY_FUNCTION__, size, length);
+		size = length;
+	}
+
+	// Final setting of mode data length
+	buf[0] = size >> 8;
+	buf[1] = size;
+
+	return size;
+}
+
+int HostServices::AddRealtimeClockPage(int page, BYTE *buf)
 {
 	if (page == 0x20) {
 		// Data structure version 1.0
@@ -131,4 +191,3 @@ int HostServices::AddVendorPage(int page, bool, BYTE *buf)
 
 	return 0;
 }
-
diff --git a/src/raspberrypi/devices/host_services.h b/src/raspberrypi/devices/host_services.h
index 5c6e8e4a..7d7aa944 100644
--- a/src/raspberrypi/devices/host_services.h
+++ b/src/raspberrypi/devices/host_services.h
@@ -5,21 +5,37 @@
 //
 // Copyright (C) 2022 Uwe Seimet
 //
+// RaSCSI Host Services with realtime clock and shutdown support
+//
 //---------------------------------------------------------------------------
 #pragma once
 
-#include "disk.h"
+#include "mode_page_device.h"
 
-class HostServices: public Disk
+using namespace std;
+
+class HostServices: public ModePageDevice
 {
+
 public:
-	HostServices() : Disk("SCHS") {};
-	~HostServices() {};
+
+	HostServices();
+	~HostServices() {}
 
 	virtual bool Dispatch(SCSIDEV *) override;
 
 	int Inquiry(const DWORD *, BYTE *) override;
 	void TestUnitReady(SASIDEV *) override;
-	void StartStopUnit(SASIDEV *) override;
-	int AddVendorPage(int, bool, BYTE *) override;
+	void StartStopUnit(SASIDEV *);
+
+	int ModeSense6(const DWORD *, BYTE *);
+	int ModeSense10(const DWORD *, BYTE *);
+
+private:
+
+	typedef ModePageDevice super;
+
+	Dispatcher<HostServices> dispatcher;
+
+	int AddRealtimeClockPage(int, BYTE *);
 };
diff --git a/src/raspberrypi/devices/interfaces/scsi_block_commands.h b/src/raspberrypi/devices/interfaces/scsi_block_commands.h
index 3a8f08de..584f6af8 100644
--- a/src/raspberrypi/devices/interfaces/scsi_block_commands.h
+++ b/src/raspberrypi/devices/interfaces/scsi_block_commands.h
@@ -30,17 +30,4 @@ public:
 	virtual void Read16(SASIDEV *) = 0;
 	virtual void Write10(SASIDEV *) = 0;
 	virtual void Write16(SASIDEV *) = 0;
-
-	// Implemented optional commands
-	virtual void ReadLong10(SASIDEV *) = 0;
-	virtual void WriteLong10(SASIDEV *) = 0;
-	virtual void Verify10(SASIDEV *) = 0;
-	virtual void ReadLong16(SASIDEV *) = 0;
-	virtual void WriteLong16(SASIDEV *) = 0;
-	virtual void Verify16(SASIDEV *) = 0;
-	virtual void ReassignBlocks(SASIDEV *) = 0;
-	virtual void SendDiagnostic(SASIDEV *) = 0;
-	virtual void StartStopUnit(SASIDEV *) = 0;
-	virtual void SynchronizeCache10(SASIDEV *) = 0;
-	virtual void SynchronizeCache16(SASIDEV *) = 0;
 };
diff --git a/src/raspberrypi/devices/interfaces/scsi_primary_commands.h b/src/raspberrypi/devices/interfaces/scsi_primary_commands.h
index 5a3efdb1..585c90e5 100644
--- a/src/raspberrypi/devices/interfaces/scsi_primary_commands.h
+++ b/src/raspberrypi/devices/interfaces/scsi_primary_commands.h
@@ -25,10 +25,6 @@ public:
 	virtual void Inquiry(SASIDEV *) = 0;
 	virtual void ReportLuns(SASIDEV *) = 0;
 
-	// Optional commands
+	// Implemented for all RaSCSI device types
 	virtual void RequestSense(SASIDEV *) = 0;
-	virtual void ModeSense6(SASIDEV *) = 0;
-	virtual void ModeSense10(SASIDEV *) = 0;
-	virtual void ModeSelect6(SASIDEV *) = 0;
-	virtual void ModeSelect10(SASIDEV *) = 0;
 };
diff --git a/src/raspberrypi/devices/mode_page_device.cpp b/src/raspberrypi/devices/mode_page_device.cpp
index 3f05caa9..9b9e08bc 100644
--- a/src/raspberrypi/devices/mode_page_device.cpp
+++ b/src/raspberrypi/devices/mode_page_device.cpp
@@ -14,36 +14,20 @@
 #include "mode_page_device.h"
 
 using namespace std;
+using namespace scsi_defs;
 
-ModePageDevice::ModePageDevice(const string id) : PrimaryDevice(id)
+ModePageDevice::ModePageDevice(const string& id) : PrimaryDevice(id)
 {
-	AddCommand(ScsiDefs::eCmdModeSense6, "ModeSense6", &ModePageDevice::ModeSense6);
-	AddCommand(ScsiDefs::eCmdModeSense10, "ModeSense10", &ModePageDevice::ModeSense10);
-	AddCommand(ScsiDefs::eCmdModeSelect6, "ModeSelect6", &ModePageDevice::ModeSelect6);
-	AddCommand(ScsiDefs::eCmdModeSelect10, "ModeSelect10", &ModePageDevice::ModeSelect10);
-}
-
-void ModePageDevice::AddCommand(ScsiDefs::scsi_command opcode, const char* name, void (ModePageDevice::*execute)(SASIDEV *))
-{
-	commands[opcode] = new command_t(name, execute);
+	dispatcher.AddCommand(eCmdModeSense6, "ModeSense6", &ModePageDevice::ModeSense6);
+	dispatcher.AddCommand(eCmdModeSense10, "ModeSense10", &ModePageDevice::ModeSense10);
+	dispatcher.AddCommand(eCmdModeSelect6, "ModeSelect6", &ModePageDevice::ModeSelect6);
+	dispatcher.AddCommand(eCmdModeSelect10, "ModeSelect10", &ModePageDevice::ModeSelect10);
 }
 
 bool ModePageDevice::Dispatch(SCSIDEV *controller)
 {
-	ctrl = controller->GetCtrl();
-
-	if (commands.count(static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0]))) {
-		command_t *command = commands[static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0])];
-
-		LOGDEBUG("%s Executing %s ($%02X)", __PRETTY_FUNCTION__, command->name, (unsigned int)ctrl->cmd[0]);
-
-		(this->*command->execute)(controller);
-
-		return true;
-	}
-
-	// Unknown command
-	return false;
+	// The superclass class handles the less specific commands
+	return dispatcher.Dispatch(this, controller) ? true : super::Dispatch(controller);
 }
 
 void ModePageDevice::ModeSense6(SASIDEV *controller)
diff --git a/src/raspberrypi/devices/mode_page_device.h b/src/raspberrypi/devices/mode_page_device.h
index 2c204e51..b8200aa2 100644
--- a/src/raspberrypi/devices/mode_page_device.h
+++ b/src/raspberrypi/devices/mode_page_device.h
@@ -18,7 +18,7 @@ class ModePageDevice: public PrimaryDevice
 {
 public:
 
-	ModePageDevice(const string);
+	ModePageDevice(const string&);
 	virtual ~ModePageDevice() {}
 
 	virtual bool Dispatch(SCSIDEV *) override;
@@ -31,20 +31,14 @@ public:
 
 private:
 
-	typedef struct _command_t {
-		const char* name;
-		void (ModePageDevice::*execute)(SASIDEV *);
+	typedef PrimaryDevice super;
 
-		_command_t(const char* _name, void (ModePageDevice::*_execute)(SASIDEV *)) : name(_name), execute(_execute) { };
-	} command_t;
-	std::map<ScsiDefs::scsi_command, command_t*> commands;
+	Dispatcher<ModePageDevice> dispatcher;
 
-	void AddCommand(ScsiDefs::scsi_command, const char*, void (ModePageDevice::*)(SASIDEV *));
-
-	void ModeSense6(SASIDEV *) override;
-	void ModeSense10(SASIDEV *) override;
-	void ModeSelect6(SASIDEV *) override;
-	void ModeSelect10(SASIDEV *) override;
+	void ModeSense6(SASIDEV *);
+	void ModeSense10(SASIDEV *);
+	void ModeSelect6(SASIDEV *);
+	void ModeSelect10(SASIDEV *);
 
 	int ModeSelectCheck(const DWORD *, int);
 	int ModeSelectCheck6(const DWORD *);
diff --git a/src/raspberrypi/devices/primary_device.cpp b/src/raspberrypi/devices/primary_device.cpp
index 75728e32..3f097bc8 100644
--- a/src/raspberrypi/devices/primary_device.cpp
+++ b/src/raspberrypi/devices/primary_device.cpp
@@ -9,44 +9,28 @@
 
 #include "log.h"
 #include "controllers/scsidev_ctrl.h"
+#include "dispatcher.h"
 #include "primary_device.h"
 
 using namespace std;
+using namespace scsi_defs;
 
-PrimaryDevice::PrimaryDevice(const string id) : ScsiPrimaryCommands(), Device(id)
+PrimaryDevice::PrimaryDevice(const string& id) : ScsiPrimaryCommands(), Device(id)
 {
 	ctrl = NULL;
 
 	// Mandatory SCSI primary commands
-	AddCommand(ScsiDefs::eCmdTestUnitReady, "TestUnitReady", &PrimaryDevice::TestUnitReady);
-	AddCommand(ScsiDefs::eCmdInquiry, "Inquiry", &PrimaryDevice::Inquiry);
-	AddCommand(ScsiDefs::eCmdReportLuns, "ReportLuns", &PrimaryDevice::ReportLuns);
+	dispatcher.AddCommand(eCmdTestUnitReady, "TestUnitReady", &PrimaryDevice::TestUnitReady);
+	dispatcher.AddCommand(eCmdInquiry, "Inquiry", &PrimaryDevice::Inquiry);
+	dispatcher.AddCommand(eCmdReportLuns, "ReportLuns", &PrimaryDevice::ReportLuns);
 
 	// Optional commands used by all RaSCSI devices
-	AddCommand(ScsiDefs::eCmdRequestSense, "RequestSense", &PrimaryDevice::RequestSense);
-}
-
-void PrimaryDevice::AddCommand(ScsiDefs::scsi_command opcode, const char* name, void (PrimaryDevice::*execute)(SASIDEV *))
-{
-	commands[opcode] = new command_t(name, execute);
+	dispatcher.AddCommand(eCmdRequestSense, "RequestSense", &PrimaryDevice::RequestSense);
 }
 
 bool PrimaryDevice::Dispatch(SCSIDEV *controller)
 {
-	ctrl = controller->GetCtrl();
-
-	if (commands.count(static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0]))) {
-		command_t *command = commands[static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0])];
-
-		LOGDEBUG("%s Executing %s ($%02X)", __PRETTY_FUNCTION__, command->name, (unsigned int)ctrl->cmd[0]);
-
-		(this->*command->execute)(controller);
-
-		return true;
-	}
-
-	// Unknown command
-	return false;
+	return dispatcher.Dispatch(this, controller);
 }
 
 void PrimaryDevice::TestUnitReady(SASIDEV *controller)
@@ -90,7 +74,7 @@ void PrimaryDevice::Inquiry(SASIDEV *controller)
 
 	// Report if the device does not support the requested LUN
 	if (!ctrl->unit[lun]) {
-		LOGDEBUG("Reporting LUN %d for device ID %d as not supported", lun, ctrl->device->GetId());
+		LOGTRACE("Reporting LUN %d for device ID %d as not supported", lun, ctrl->device->GetId());
 
 		ctrl->buffer[0] |= 0x7f;
 	}
@@ -183,6 +167,33 @@ bool PrimaryDevice::CheckReady()
 	return true;
 }
 
+int PrimaryDevice::Inquiry(int type, bool is_removable, const DWORD *cdb, BYTE *buf)
+{
+	int allocation_length = cdb[4] + (((DWORD)cdb[3]) << 8);
+	if (allocation_length > 4) {
+		if (allocation_length > 44) {
+			allocation_length = 44;
+		}
+
+		// Basic data
+		// buf[0] ... SCSI Device type
+		// buf[1] ... Bit 7: Removable/not removable
+		// buf[2] ... SCSI-2 compliant command system
+		// buf[3] ... SCSI-2 compliant Inquiry response
+		// buf[4] ... Inquiry additional data
+		memset(buf, 0, allocation_length);
+		buf[0] = type;
+		buf[1] = is_removable ? 0x80 : 0x00;
+		buf[2] = 0x01;
+		buf[4] = 0x1F;
+
+		// Padded vendor, product, revision
+		memcpy(&buf[8], GetPaddedName().c_str(), 28);
+	}
+
+	return allocation_length;
+}
+
 int PrimaryDevice::RequestSense(const DWORD *cdb, BYTE *buf)
 {
 	ASSERT(cdb);
diff --git a/src/raspberrypi/devices/primary_device.h b/src/raspberrypi/devices/primary_device.h
index 6949e17b..1068afdc 100644
--- a/src/raspberrypi/devices/primary_device.h
+++ b/src/raspberrypi/devices/primary_device.h
@@ -11,11 +11,11 @@
 
 #pragma once
 
-#include "controllers/sasidev_ctrl.h"
+#include "controllers/scsidev_ctrl.h"
 #include "interfaces/scsi_primary_commands.h"
 #include "device.h"
+#include "dispatcher.h"
 #include <string>
-#include <map>
 
 using namespace std;
 
@@ -23,33 +23,29 @@ class PrimaryDevice: public Device, virtual public ScsiPrimaryCommands
 {
 public:
 
-	PrimaryDevice(const string);
+	PrimaryDevice(const string&);
 	virtual ~PrimaryDevice() {}
 
-	virtual bool Dispatch(SCSIDEV *) override;
+	virtual bool Dispatch(SCSIDEV *);
 
 	void TestUnitReady(SASIDEV *);
 	void RequestSense(SASIDEV *);
 
+	void SetCtrl(SASIDEV::ctrl_t *ctrl) { this->ctrl = ctrl; }
+
 	bool CheckReady();
 	virtual int Inquiry(const DWORD *, BYTE *) = 0;
 	virtual int RequestSense(const DWORD *, BYTE *);
 
 protected:
 
+	int Inquiry(int, bool, const DWORD *, BYTE *);
+
 	SASIDEV::ctrl_t *ctrl;
 
 private:
 
-	typedef struct _command_t {
-		const char* name;
-		void (PrimaryDevice::*execute)(SASIDEV *);
-
-		_command_t(const char* _name, void (PrimaryDevice::*_execute)(SASIDEV *)) : name(_name), execute(_execute) { };
-	} command_t;
-	std::map<ScsiDefs::scsi_command, command_t*> commands;
-
-	void AddCommand(ScsiDefs::scsi_command, const char*, void (PrimaryDevice::*)(SASIDEV *));
+	Dispatcher<PrimaryDevice> dispatcher;
 
 	void Inquiry(SASIDEV *);
 	void ReportLuns(SASIDEV *);
diff --git a/src/raspberrypi/devices/sasihd.cpp b/src/raspberrypi/devices/sasihd.cpp
index ec901478..be8293d2 100644
--- a/src/raspberrypi/devices/sasihd.cpp
+++ b/src/raspberrypi/devices/sasihd.cpp
@@ -13,11 +13,11 @@
 //  	[ SASI hard disk ]
 //
 //---------------------------------------------------------------------------
+
 #include "sasihd.h"
 #include "fileio.h"
 #include "exceptions.h"
-#include <sstream>
-#include "../rascsi.h"
+#include "../config.h"
 
 //===========================================================================
 //
diff --git a/src/raspberrypi/devices/scsi_daynaport.cpp b/src/raspberrypi/devices/scsi_daynaport.cpp
index 5c55f678..a789fc00 100644
--- a/src/raspberrypi/devices/scsi_daynaport.cpp
+++ b/src/raspberrypi/devices/scsi_daynaport.cpp
@@ -28,23 +28,25 @@
 //---------------------------------------------------------------------------
 
 #include "scsi_daynaport.h"
-#include <sstream>
+
+using namespace scsi_defs;
 
 const BYTE SCSIDaynaPort::m_bcast_addr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 const BYTE SCSIDaynaPort::m_apple_talk_addr[6] = { 0x09, 0x00, 0x07, 0xff, 0xff, 0xff };
 
+// TODO Disk should not be the superclass
 SCSIDaynaPort::SCSIDaynaPort() : Disk("SCDP")
 {
 	m_tap = NULL;
 	m_bTapEnable = false;
 
-	AddCommand(ScsiDefs::eCmdTestUnitReady, "TestUnitReady", &SCSIDaynaPort::TestUnitReady);
-	AddCommand(ScsiDefs::eCmdRead6, "Read6", &SCSIDaynaPort::Read6);
-	AddCommand(ScsiDefs::eCmdWrite6, "Write6", &SCSIDaynaPort::Write6);
-	AddCommand(ScsiDefs::eCmdRetrieveStats, "RetrieveStats", &SCSIDaynaPort::RetrieveStatistics);
-	AddCommand(ScsiDefs::eCmdSetIfaceMode, "SetIfaceMode", &SCSIDaynaPort::SetInterfaceMode);
-	AddCommand(ScsiDefs::eCmdSetMcastAddr, "SetMcastAddr", &SCSIDaynaPort::SetMcastAddr);
-	AddCommand(ScsiDefs::eCmdEnableInterface, "EnableInterface", &SCSIDaynaPort::EnableInterface);
+	dispatcher.AddCommand(eCmdTestUnitReady, "TestUnitReady", &SCSIDaynaPort::TestUnitReady);
+	dispatcher.AddCommand(eCmdRead6, "Read6", &SCSIDaynaPort::Read6);
+	dispatcher.AddCommand(eCmdWrite6, "Write6", &SCSIDaynaPort::Write6);
+	dispatcher.AddCommand(eCmdRetrieveStats, "RetrieveStats", &SCSIDaynaPort::RetrieveStatistics);
+	dispatcher.AddCommand(eCmdSetIfaceMode, "SetIfaceMode", &SCSIDaynaPort::SetInterfaceMode);
+	dispatcher.AddCommand(eCmdSetMcastAddr, "SetMcastAddr", &SCSIDaynaPort::SetMcastAddr);
+	dispatcher.AddCommand(eCmdEnableInterface, "EnableInterface", &SCSIDaynaPort::EnableInterface);
 }
 
 SCSIDaynaPort::~SCSIDaynaPort()
@@ -54,35 +56,12 @@ SCSIDaynaPort::~SCSIDaynaPort()
 		m_tap->Cleanup();
 		delete m_tap;
 	}
-
-	for (auto const& command : commands) {
-		delete command.second;
-	}
-}
-
-void SCSIDaynaPort::AddCommand(ScsiDefs::scsi_command opcode, const char* name, void (SCSIDaynaPort::*execute)(SASIDEV *))
-{
-	commands[opcode] = new command_t(name, execute);
 }
 
 bool SCSIDaynaPort::Dispatch(SCSIDEV *controller)
 {
-	ctrl = controller->GetCtrl();
-
-	if (commands.count(static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0]))) {
-		command_t *command = commands[static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0])];
-
-		LOGDEBUG("%s Executing %s ($%02X)", __PRETTY_FUNCTION__, command->name, (unsigned int)ctrl->cmd[0]);
-
-		(this->*command->execute)(controller);
-
-		return true;
-	}
-
-	LOGTRACE("%s Calling base class for dispatching $%02X", __PRETTY_FUNCTION__, (unsigned int)ctrl->cmd[0]);
-
-	// The base class handles the less specific commands
-	return Disk::Dispatch(controller);
+	// The superclass class handles the less specific commands
+	return dispatcher.Dispatch(this, controller) ? true : super::Dispatch(controller);
 }
 
 bool SCSIDaynaPort::Init(const map<string, string>& params)
@@ -133,36 +112,10 @@ void SCSIDaynaPort::Open(const Filepath& path)
 	m_tap->OpenDump(path);
 }
 
-//---------------------------------------------------------------------------
-//
-//	INQUIRY
-//
-//---------------------------------------------------------------------------
 int SCSIDaynaPort::Inquiry(const DWORD *cdb, BYTE *buf)
 {
-	int allocation_length = cdb[4] + (((DWORD)cdb[3]) << 8);
-	if (allocation_length > 4) {
-		if (allocation_length > 44) {
-			allocation_length = 44;
-		}
-
-		// Basic data
-		// buf[0] ... Processor Device
-		// buf[1] ... Not removable
-		// buf[2] ... SCSI-2 compliant command system
-		// buf[3] ... SCSI-2 compliant Inquiry response
-		// buf[4] ... Inquiry additional data
-		// http://www.bitsavers.org/pdf/apple/scsi/dayna/daynaPORT/pocket_scsiLINK/pocketscsilink_inq.png
-		memset(buf, 0, allocation_length);
-		buf[0] = 0x03;
-		buf[2] = 0x01;
-		buf[4] = 0x1F;
-
-		// Padded vendor, product, revision
-		memcpy(&buf[8], GetPaddedName().c_str(), 28);
-	}
-
-	return allocation_length;
+	// Processor device, not removable
+	return PrimaryDevice::Inquiry(3, false, cdb, buf);
 }
 
 //---------------------------------------------------------------------------
@@ -201,10 +154,6 @@ int SCSIDaynaPort::Read(const DWORD *cdb, BYTE *buf, uint64_t block)
 	int rx_packet_size = 0;
 	scsi_resp_read_t *response = (scsi_resp_read_t*)buf;
 
-	ostringstream s;
-	s << __PRETTY_FUNCTION__ << " reading DaynaPort block " << block;
-	LOGTRACE("%s", s.str().c_str());
-
 	int requested_length = cdb[4];
 	LOGTRACE("%s Read maximum length %d, (%04X)", __PRETTY_FUNCTION__, requested_length, requested_length);
 
diff --git a/src/raspberrypi/devices/scsi_daynaport.h b/src/raspberrypi/devices/scsi_daynaport.h
index 1a08b4f2..404965d3 100644
--- a/src/raspberrypi/devices/scsi_daynaport.h
+++ b/src/raspberrypi/devices/scsi_daynaport.h
@@ -42,19 +42,6 @@
 class SCSIDaynaPort: public Disk
 {
 
-private:
-	typedef struct _command_t {
-		const char* name;
-		void (SCSIDaynaPort::*execute)(SASIDEV *);
-
-		_command_t(const char* _name, void (SCSIDaynaPort::*_execute)(SASIDEV *)) : name(_name), execute(_execute) { };
-	} command_t;
-	std::map<ScsiDefs::scsi_command, command_t*> commands;
-
-	SASIDEV::ctrl_t *ctrl;
-
-	void AddCommand(ScsiDefs::scsi_command, const char*, void (SCSIDaynaPort::*)(SASIDEV *));
-
 public:
 	SCSIDaynaPort();
 	~SCSIDaynaPort();
@@ -103,6 +90,10 @@ public:
 	static const DWORD DAYNAPORT_READ_HEADER_SZ = 2 + 4;
 
 private:
+	typedef Disk super;
+
+	Dispatcher<SCSIDaynaPort> dispatcher;
+
 	typedef struct __attribute__((packed)) {
 		BYTE operation_code;
 		BYTE misc_cdb_information;
diff --git a/src/raspberrypi/devices/scsi_host_bridge.cpp b/src/raspberrypi/devices/scsi_host_bridge.cpp
index 73d6cd4d..a4a956c8 100644
--- a/src/raspberrypi/devices/scsi_host_bridge.cpp
+++ b/src/raspberrypi/devices/scsi_host_bridge.cpp
@@ -16,17 +16,19 @@
 //        work with the Sharp X68000 operating system.
 //---------------------------------------------------------------------------
 
+#include "controllers/scsidev_ctrl.h"
 #include "scsi_host_bridge.h"
 #include "ctapdriver.h"
 #include "cfilesystem.h"
-#include <sstream>
 
 using namespace std;
+using namespace scsi_defs;
 
-SCSIBR::SCSIBR() : Disk("SCBR")
+SCSIBR::SCSIBR() : PrimaryDevice("SCBR")
 {
 	tap = NULL;
 	m_bTapEnable = false;
+	packet_enable = false;
 
 	fsoptlen = 0;
 	fsoutlen = 0;
@@ -37,9 +39,9 @@ SCSIBR::SCSIBR() : Disk("SCBR")
 	fs = new CFileSys();
 	fs->Reset();
 
-	AddCommand(ScsiDefs::eCmdTestUnitReady, "TestUnitReady", &SCSIBR::TestUnitReady);
-	AddCommand(ScsiDefs::eCmdRead6, "GetMessage10", &SCSIBR::GetMessage10);
-	AddCommand(ScsiDefs::eCmdWrite6, "SendMessage10", &SCSIBR::SendMessage10);
+	dispatcher.AddCommand(eCmdTestUnitReady, "TestUnitReady", &SCSIBR::TestUnitReady);
+	dispatcher.AddCommand(eCmdRead6, "GetMessage10", &SCSIBR::GetMessage10);
+	dispatcher.AddCommand(eCmdWrite6, "SendMessage10", &SCSIBR::SendMessage10);
 }
 
 SCSIBR::~SCSIBR()
@@ -55,10 +57,6 @@ SCSIBR::~SCSIBR()
 		fs->Reset();
 		delete fs;
 	}
-
-	for (auto const& command : commands) {
-		delete command.second;
-	}
 }
 
 bool SCSIBR::Init(const map<string, string>& params)
@@ -96,29 +94,10 @@ bool SCSIBR::Init(const map<string, string>& params)
 #endif
 }
 
-void SCSIBR::AddCommand(ScsiDefs::scsi_command opcode, const char* name, void (SCSIBR::*execute)(SASIDEV *))
-{
-	commands[opcode] = new command_t(name, execute);
-}
-
 bool SCSIBR::Dispatch(SCSIDEV *controller)
 {
-	ctrl = controller->GetCtrl();
-
-	if (commands.count(static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0]))) {
-		command_t *command = commands[static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0])];
-
-		LOGDEBUG("%s Executing %s ($%02X)", __PRETTY_FUNCTION__, command->name, (unsigned int)ctrl->cmd[0]);
-
-		(this->*command->execute)(controller);
-
-		return true;
-	}
-
-	LOGTRACE("%s Calling base class for dispatching $%02X", __PRETTY_FUNCTION__, (unsigned int)ctrl->cmd[0]);
-
-	// The base class handles the less specific commands
-	return Disk::Dispatch(controller);
+	// The superclass class handles the less specific commands
+	return dispatcher.Dispatch(this, controller) ? true : super::Dispatch(controller);
 }
 
 //---------------------------------------------------------------------------
@@ -128,14 +107,10 @@ bool SCSIBR::Dispatch(SCSIDEV *controller)
 //---------------------------------------------------------------------------
 int SCSIBR::Inquiry(const DWORD *cdb, BYTE *buf)
 {
-	ASSERT(cdb);
-	ASSERT(buf);
-	ASSERT(cdb[0] == 0x12);
-
 	// EVPD check
 	if (cdb[1] & 0x01) {
 		SetStatusCode(STATUS_INVALIDCDB);
-		return FALSE;
+		return 0;
 	}
 
 	// Basic data
@@ -175,15 +150,9 @@ int SCSIBR::Inquiry(const DWORD *cdb, BYTE *buf)
 	return size;
 }
 
-//---------------------------------------------------------------------------
-//
-//	TEST UNIT READY
-//
-//---------------------------------------------------------------------------
 void SCSIBR::TestUnitReady(SASIDEV *controller)
 {
-	// TEST UNIT READY Success
-
+	// Always successful
 	controller->Status();}
 
 //---------------------------------------------------------------------------
diff --git a/src/raspberrypi/devices/scsi_host_bridge.h b/src/raspberrypi/devices/scsi_host_bridge.h
index 1ecee189..81b19dfd 100644
--- a/src/raspberrypi/devices/scsi_host_bridge.h
+++ b/src/raspberrypi/devices/scsi_host_bridge.h
@@ -18,7 +18,7 @@
 #pragma once
 
 #include "os.h"
-#include "disk.h"
+#include "primary_device.h"
 #include <string>
 
 //===========================================================================
@@ -29,22 +29,9 @@
 class CTapDriver;
 class CFileSys;
 
-class SCSIBR : public Disk
+class SCSIBR : public PrimaryDevice
 {
 
-private:
-	typedef struct _command_t {
-		const char* name;
-		void (SCSIBR::*execute)(SASIDEV *);
-
-		_command_t(const char* _name, void (SCSIBR::*_execute)(SASIDEV *)) : name(_name), execute(_execute) { };
-	} command_t;
-	std::map<ScsiDefs::scsi_command, command_t*> commands;
-
-	SASIDEV::ctrl_t *ctrl;
-
-	void AddCommand(ScsiDefs::scsi_command, const char*, void (SCSIBR::*)(SASIDEV *));
-
 public:
 	SCSIBR();
 	~SCSIBR();
@@ -61,6 +48,10 @@ public:
 	void SendMessage10(SASIDEV *);
 
 private:
+	typedef PrimaryDevice super;
+
+	Dispatcher<SCSIBR> dispatcher;
+
 	int GetMacAddr(BYTE *buf);					// Get MAC address
 	void SetMacAddr(BYTE *buf);					// Set MAC address
 	void ReceivePacket();						// Receive a packet
diff --git a/src/raspberrypi/devices/scsicd.cpp b/src/raspberrypi/devices/scsicd.cpp
index 1744b7f6..a250c443 100644
--- a/src/raspberrypi/devices/scsicd.cpp
+++ b/src/raspberrypi/devices/scsicd.cpp
@@ -10,14 +10,15 @@
 //	Licensed under the BSD 3-Clause License. 
 //	See LICENSE file in the project root folder.
 //
-//	[ SCSI CD-ROM for Apple Macintosh ]
+//	[ SCSI CD-ROM ]
 //
 //---------------------------------------------------------------------------
 
 #include "scsicd.h"
 #include "fileio.h"
 #include "exceptions.h"
-#include <sstream>
+
+using namespace scsi_defs;
 
 //===========================================================================
 //
@@ -240,8 +241,8 @@ SCSICD::SCSICD() : Disk("SCCD"), ScsiMmcCommands(), FileSupport()
 	dataindex = -1;
 	audioindex = -1;
 
-	AddCommand(ScsiDefs::eCmdReadToc, "ReadToc", &SCSICD::ReadToc);
-	AddCommand(ScsiDefs::eCmdGetEventStatusNotification, "GetEventStatusNotification", &SCSICD::GetEventStatusNotification);
+	dispatcher.AddCommand(eCmdReadToc, "ReadToc", &SCSICD::ReadToc);
+	dispatcher.AddCommand(eCmdGetEventStatusNotification, "GetEventStatusNotification", &SCSICD::GetEventStatusNotification);
 }
 
 //---------------------------------------------------------------------------
@@ -253,35 +254,12 @@ SCSICD::~SCSICD()
 {
 	// Clear track
 	ClearTrack();
-
-	for (auto const& command : commands) {
-		delete command.second;
-	}
-}
-
-void SCSICD::AddCommand(ScsiDefs::scsi_command opcode, const char* name, void (SCSICD::*execute)(SASIDEV *))
-{
-	commands[opcode] = new command_t(name, execute);
 }
 
 bool SCSICD::Dispatch(SCSIDEV *controller)
 {
-	ctrl = controller->GetCtrl();
-
-	if (commands.count(static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0]))) {
-		command_t *command = commands[static_cast<ScsiDefs::scsi_command>(ctrl->cmd[0])];
-
-		LOGDEBUG("%s Executing %s ($%02X)", __PRETTY_FUNCTION__, command->name, (unsigned int)ctrl->cmd[0]);
-
-		(this->*command->execute)(controller);
-
-		return true;
-	}
-
-	LOGTRACE("%s Calling base class for dispatching $%02X", __PRETTY_FUNCTION__, (unsigned int)ctrl->cmd[0]);
-
-	// The base class handles the less specific commands
-	return Disk::Dispatch(controller);
+	// The superclass class handles the less specific commands
+	return dispatcher.Dispatch(this, controller) ? true : super::Dispatch(controller);
 }
 
 //---------------------------------------------------------------------------
@@ -421,9 +399,8 @@ void SCSICD::OpenIso(const Filepath& path)
 	if (rawfile) {
 		// Size must be a multiple of 2536
 		if (size % 2536) {
-			stringstream error;
-			error << "Raw ISO CD-ROM file size must be a multiple of 2536 bytes but is " << size << " bytes";
-			throw io_exception(error.str());
+			throw io_exception("Raw ISO CD-ROM file size must be a multiple of 2536 bytes but is "
+					+ to_string(size) + " bytes");
 		}
 
 		// Set the number of blocks
@@ -499,13 +476,10 @@ void SCSICD::ReadToc(SASIDEV *controller)
 //---------------------------------------------------------------------------
 int SCSICD::Inquiry(const DWORD *cdb, BYTE *buf)
 {
-	ASSERT(cdb);
-	ASSERT(buf);
-
 	// EVPD check
 	if (cdb[1] & 0x01) {
 		SetStatusCode(STATUS_INVALIDCDB);
-		return FALSE;
+		return 0;
 	}
 
 	// Basic data
diff --git a/src/raspberrypi/devices/scsicd.h b/src/raspberrypi/devices/scsicd.h
index 2e860467..c52719ab 100644
--- a/src/raspberrypi/devices/scsicd.h
+++ b/src/raspberrypi/devices/scsicd.h
@@ -71,25 +71,12 @@ private:
 //===========================================================================
 class SCSICD : public Disk, public ScsiMmcCommands, public FileSupport
 {
-private:
-	typedef struct _command_t {
-		const char* name;
-		void (SCSICD::*execute)(SASIDEV *);
-
-		_command_t(const char* _name, void (SCSICD::*_execute)(SASIDEV *)) : name(_name), execute(_execute) { };
-	} command_t;
-	std::map<ScsiDefs::scsi_command, command_t*> commands;
-
-	SASIDEV::ctrl_t *ctrl;
-
-	void AddCommand(ScsiDefs::scsi_command, const char*, void (SCSICD::*)(SASIDEV *));
 
 public:
 	enum {
 		TrackMax = 96							// Maximum number of tracks
 	};
 
-public:
 	SCSICD();
 	~SCSICD();
 
@@ -103,6 +90,10 @@ public:
 	int ReadToc(const DWORD *cdb, BYTE *buf);			// READ TOC command
 
 private:
+	typedef Disk super;
+
+	Dispatcher<SCSICD> dispatcher;
+
 	// Open
 	void OpenCue(const Filepath& path);				// Open(CUE)
 	void OpenIso(const Filepath& path);				// Open(ISO)
diff --git a/src/raspberrypi/devices/scsihd.cpp b/src/raspberrypi/devices/scsihd.cpp
index 7b509094..58981a05 100644
--- a/src/raspberrypi/devices/scsihd.cpp
+++ b/src/raspberrypi/devices/scsihd.cpp
@@ -119,9 +119,6 @@ void SCSIHD::Open(const Filepath& path)
 //---------------------------------------------------------------------------
 int SCSIHD::Inquiry(const DWORD *cdb, BYTE *buf)
 {
-	ASSERT(cdb);
-	ASSERT(buf);
-
 	// EVPD check
 	if (cdb[1] & 0x01) {
 		SetStatusCode(STATUS_INVALIDCDB);
diff --git a/src/raspberrypi/devices/scsimo.cpp b/src/raspberrypi/devices/scsimo.cpp
index 83496ed6..75d1bc2c 100644
--- a/src/raspberrypi/devices/scsimo.cpp
+++ b/src/raspberrypi/devices/scsimo.cpp
@@ -18,7 +18,6 @@
 
 #include "fileio.h"
 #include "exceptions.h"
-#include <sstream>
 
 //===========================================================================
 //
diff --git a/src/raspberrypi/fileio.cpp b/src/raspberrypi/fileio.cpp
index 066abddd..c6dc70b2 100644
--- a/src/raspberrypi/fileio.cpp
+++ b/src/raspberrypi/fileio.cpp
@@ -11,7 +11,8 @@
 #include "os.h"
 #include "filepath.h"
 #include "fileio.h"
-#include "rascsi.h"
+
+#include "config.h"
 
 //===========================================================================
 //
diff --git a/src/raspberrypi/filepath.cpp b/src/raspberrypi/filepath.cpp
index 65555218..1088bcd7 100644
--- a/src/raspberrypi/filepath.cpp
+++ b/src/raspberrypi/filepath.cpp
@@ -10,8 +10,8 @@
 
 #include "os.h"
 #include "filepath.h"
+#include "config.h"
 #include "fileio.h"
-#include "rascsi.h"
 
 //===========================================================================
 //
diff --git a/src/raspberrypi/gpiobus.cpp b/src/raspberrypi/gpiobus.cpp
index f09372af..e1797bb0 100644
--- a/src/raspberrypi/gpiobus.cpp
+++ b/src/raspberrypi/gpiobus.cpp
@@ -16,8 +16,9 @@
 
 #include "os.h"
 #include "gpiobus.h"
+
+#include "config.h"
 #include "log.h"
-#include "rascsi.h"
 
 #ifdef __linux__
 //---------------------------------------------------------------------------
diff --git a/src/raspberrypi/gpiobus.h b/src/raspberrypi/gpiobus.h
index 46babdce..78b01b54 100644
--- a/src/raspberrypi/gpiobus.h
+++ b/src/raspberrypi/gpiobus.h
@@ -12,7 +12,7 @@
 #if !defined(gpiobus_h)
 #define gpiobus_h
 
-#include "rascsi.h"
+#include "config.h"
 #include "scsi.h"
 
 //---------------------------------------------------------------------------
diff --git a/src/raspberrypi/rascsi.cpp b/src/raspberrypi/rascsi.cpp
index 1747e39a..1243720d 100644
--- a/src/raspberrypi/rascsi.cpp
+++ b/src/raspberrypi/rascsi.cpp
@@ -10,7 +10,6 @@
 //
 //---------------------------------------------------------------------------
 
-#include "rascsi.h"
 #include "os.h"
 #include "controllers/sasidev_ctrl.h"
 #include "devices/device_factory.h"
@@ -34,6 +33,7 @@
 #include <list>
 #include <vector>
 #include <map>
+#include "config.h"
 
 using namespace std;
 using namespace spdlog;
@@ -520,17 +520,17 @@ string SetReservedIds(const string& ids)
     reserved_ids = reserved;
 
     if (!reserved_ids.empty()) {
-    	ostringstream s;
+    	string s;
     	bool isFirst = true;
     	for (auto const& reserved_id : reserved_ids) {
     		if (!isFirst) {
-    			s << ", ";
+    			s += ", ";
     		}
     		isFirst = false;
-    		s << reserved_id;
+    		s += to_string(reserved_id);
     	}
 
-    	LOGINFO("Reserved ID(s) set to %s", s.str().c_str());
+    	LOGINFO("Reserved ID(s) set to %s", s.c_str());
     }
     else {
     	LOGINFO("Cleared reserved IDs");
@@ -580,15 +580,14 @@ bool Attach(const CommandContext& context, const PbDeviceDefinition& pb_device,
 	if (unit >= supported_luns) {
 		delete device;
 
-		ostringstream error;
-		error << "Invalid unit " << unit << " for device type " << PbDeviceType_Name(type);
+		string error = "Invalid unit " + to_string(unit) + " for device type " + PbDeviceType_Name(type);
 		if (supported_luns == 1) {
-			error << " (0)";
+			error += " (0)";
 		}
 		else {
-			error << " (0-" << (supported_luns -1) << ")";
+			error += " (0-" + to_string(supported_luns -1) + ")";
 		}
-		return ReturnStatus(context, false, error.str());
+		return ReturnStatus(context, false, error);
 	}
 
 	// If no filename was provided the medium is considered removed
@@ -709,16 +708,15 @@ bool Attach(const CommandContext& context, const PbDeviceDefinition& pb_device,
 
 	// Re-map the controller
 	if (MapController(map)) {
-		ostringstream msg;
-		msg << "Attached ";
+		string msg = "Attached ";
 		if (device->IsReadOnly()) {
-			msg << "read-only ";
+			msg += "read-only ";
 		}
 		else if (device->IsProtectable() && device->IsProtected()) {
-			msg << "protected ";
+			msg += "protected ";
 		}
-		msg << device->GetType() << " device, ID " << id << ", unit " << unit;
-		LOGINFO("%s", msg.str().c_str());
+		msg += device->GetType() + " device, ID " + to_string(id) + ", unit " + to_string(unit);
+		LOGINFO("%s", msg.c_str());
 
 		return true;
 	}
@@ -840,8 +838,6 @@ void TerminationHandler(int signum)
 
 bool ProcessCmd(const CommandContext& context, const PbDeviceDefinition& pb_device, const PbCommand& command, bool dryRun)
 {
-	ostringstream error;
-
 	const int id = pb_device.id();
 	const int unit = pb_device.unit();
 	const PbDeviceType type = pb_device.type();
diff --git a/src/raspberrypi/rascsi_response.cpp b/src/raspberrypi/rascsi_response.cpp
index a9ff6883..6f7b1fbf 100644
--- a/src/raspberrypi/rascsi_response.cpp
+++ b/src/raspberrypi/rascsi_response.cpp
@@ -70,7 +70,7 @@ void RascsiResponse::GetAllDeviceTypeProperties(PbDeviceTypesInfo& device_types_
 	int ordinal = 1;
 	while (PbDeviceType_IsValid(ordinal)) {
 		PbDeviceType type = UNDEFINED;
-		PbDeviceType_Parse(PbDeviceType_Name(ordinal), &type);
+		PbDeviceType_Parse(PbDeviceType_Name((PbDeviceType)ordinal), &type);
 		GetDeviceTypeProperties(device_types_info, type);
 		ordinal++;
 	}
diff --git a/src/raspberrypi/rasctl_commands.cpp b/src/raspberrypi/rasctl_commands.cpp
index af4e21e3..f192432d 100644
--- a/src/raspberrypi/rasctl_commands.cpp
+++ b/src/raspberrypi/rasctl_commands.cpp
@@ -14,7 +14,6 @@
 #include "rasutil.h"
 #include "rasctl_commands.h"
 #include "rascsi_interface.pb.h"
-#include <sstream>
 #include <iostream>
 #include <list>
 
@@ -66,9 +65,8 @@ void RasctlCommands::SendCommand()
     	memcpy(&server.sin_addr.s_addr, host->h_addr, host->h_length);
 
     	if (connect(fd, (struct sockaddr *)&server, sizeof(struct sockaddr_in)) < 0) {
-    		ostringstream error;
-    		error << "Can't connect to rascsi process on host '" << hostname << "', port " << port;
-    		throw io_exception(error.str());
+    		throw io_exception("Can't connect to rascsi process on host '" + hostname + "', port "
+    				+ to_string(port));
     	}
 
     	if (write(fd, "RASCSI", 6) != 6) {
diff --git a/src/raspberrypi/sasidump.cpp b/src/raspberrypi/sasidump.cpp
index c0d3ac0f..92d6dc48 100644
--- a/src/raspberrypi/sasidump.cpp
+++ b/src/raspberrypi/sasidump.cpp
@@ -23,7 +23,6 @@
 #include "fileio.h"
 #include "filepath.h"
 #include "gpiobus.h"
-#include "rascsi.h"
 #include "rascsi_version.h"
 
 #define BUFSIZE 1024 * 64			// Maybe around 64KB?
diff --git a/src/raspberrypi/scsi.h b/src/raspberrypi/scsi.h
index 98897efd..ad4f62ee 100644
--- a/src/raspberrypi/scsi.h
+++ b/src/raspberrypi/scsi.h
@@ -154,8 +154,7 @@ private:
 	static const char* phase_str_table[];
 };
 
-class ScsiDefs {
-public:
+namespace scsi_defs {
 	enum scsi_command : int {
 		eCmdTestUnitReady = 0x00,
 		eCmdRezero =  0x01,