diff --git a/bin/History.txt b/bin/History.txt
index cb358a3e..3918bdff 100644
--- a/bin/History.txt
+++ b/bin/History.txt
@@ -10,16 +10,24 @@ Tom Charlesworth
 
 1.29.3.0 - 12 Oct 2019
 ----------------------
-. [Bug #700] Fixed ProDOS8 2.5.0 alpha6 (support INC $C08B to set LC to write mode).
+. [Change #692] Added command line switch to unplug HDD controller card on exit:
+	- -s7-empty-on-exit
+. [Change #689] Added command line switches to set CPU speed and machine type:
+	- -clock-multiplier <value>, where value is a [0.5-3.9] base-clock multiplier (ie. same as the Config UI's slider)
+	- -model <apple2|apple2p|apple2e|apple2ee>
+. [Change #666] Debugger: support showing video v,h and cycle count.
+	- videoinfo <dec|hex|apple|real> to configure display.
+	- added auto-run of DebuggerAutoRun.txt on AppleWin initial start-up.
+. [Bug #700] Fixed ProDOS8 2.5.0 alpha6:
+	- support INC $C08B (and similar) to set LC to write mode - 65C02 only.
+	- support INC $C08B,X (X=0) to set LC to write mode - 6502/65C02/816. (Fixes #404)
 . [Bug #695] Fixed WOZ 'Taipan' not booting.
 	- fixed reading write protect on a write access & support Sequencer Function.
 . [Bug #668] Fixed WOZ 'Seafox' not booting.
 	- set machine = Unenhanced Apple //e or lower & need slot2 empty.
-	- disable SSC in slot-2 using: '-s2 empty' command line.
+	- disable SSC in slot-2 using: '-s2 empty' command line switch.
 	- added '-s1 empty', '-s3 empty' and '-s6 empty' too.
-. [Bug #666] Debugger: support showing video v,h and cycle count.
-	- videoinfo <dec|hex|apple|real> to configure display.
-	- added auto-run of DebuggerAutoRun.txt on AppleWin initial start-up.
+. [Bug #404] a2audit.dsk 1.06 now working. (See #700)
 . [Bug #319] SmartPort return address was wrong when crossing page (fix to slot-7 HDD's firmware).
 . [PR #687] Replace char * with std::string.
 
diff --git a/help/CommandLine.html b/help/CommandLine.html
index 8a396b01..831b7cf9 100644
--- a/help/CommandLine.html
+++ b/help/CommandLine.html
@@ -19,6 +19,10 @@
 		Start with hard disk 1 plugged-in (and auto power-on the Apple II). NB. Hard disk controller card gets enabled.<br><br>
 		-h2 &lt;pathname&gt;<br>
 		Start with hard disk 2 plugged-in. NB. Hard disk controller card gets enabled.<br><br>
+		-model &lt;apple2|apple2p|apple2e|apple2ee&gt;<br>
+		Select the machine model: Apple II, Apple II+, Apple //e, Enhanced Apple //e.<br><br>
+		-clock-multiplier &lt;value&gt;<br>
+		Where value is between 0.5 and 3.9, and is a base-clock multiplier, roughly mapping to 0.5MHz - 3.9MHz<br><br>
 		-s0 &lt;saturn|saturn64|saturn128&gt;<br>
 		Insert a Saturn 64K or Saturn 128K card into slot 0 in the Apple II or II+ machines (or similar clone).<br>
 		Where -s0 saturn is an alias for -s0 saturn128.<br><br>
@@ -36,6 +40,8 @@
 		-s7 empty<br>
 		Remove the hard disk controller card from slot 7.<br>
 		Useful to allow a floppy disk to boot from slot 6, drive 1. Use in combination with -d1.<br><br>
+		-s7-empty-on-exit<br>
+		Remove the hard disk controller card from slot 7 on AppleWin exit.<br><br>
 		-r &lt;number of pages&gt;<br>
 		Emulate a RamWorks III card with 1 to 127 pages (each page is 64K, giving a max of 8MB) in the auxiliary slot in an Apple //e machine.<br><br>
 		-load-state &lt;savestate&gt;<br>
diff --git a/source/Applewin.cpp b/source/Applewin.cpp
index 5d028141..b6cd6409 100644
--- a/source/Applewin.cpp
+++ b/source/Applewin.cpp
@@ -392,6 +392,27 @@ double Get6502BaseClock(void)
 	return (GetVideoRefreshRate() == VR_50HZ) ? CLK_6502_PAL : CLK_6502_NTSC;
 }
 
+void UseClockMultiplier(double clockMultiplier)
+{
+	if (clockMultiplier == 0.0)
+		return;
+
+	if (clockMultiplier < 1.0)
+	{
+		if (clockMultiplier < 0.5)
+			clockMultiplier = 0.5;
+		g_dwSpeed = (ULONG)((clockMultiplier - 0.5) * 20);	// [0.5..0.9] -> [0..9]
+	}
+	else
+	{
+		g_dwSpeed = (ULONG)(clockMultiplier * 10);
+		if (g_dwSpeed >= SPEED_MAX)
+			g_dwSpeed = SPEED_MAX - 1;
+	}
+
+	SetCurrentCLK6502();
+}
+
 void SetCurrentCLK6502(void)
 {
 	static DWORD dwPrevSpeed = (DWORD) -1;
@@ -1168,6 +1189,18 @@ static void InsertHardDisks(LPSTR szImageName_harddisk[NUM_HARDDISKS], bool& bBo
 		MessageBox(g_hFrameWindow, "Failed to insert harddisk(s) - see log file", "Warning", MB_ICONASTERISK | MB_OK);
 }
 
+static void UnplugHardDiskControllerCard(void)
+{
+	HD_SetEnabled(false);
+
+	DWORD dwTmp;
+	if (REGLOAD(TEXT(REGVALUE_HDD_ENABLED), &dwTmp))
+	{
+		if (dwTmp)
+			REGSAVE(TEXT(REGVALUE_HDD_ENABLED), 0);	// Config: HDD Disabled
+	}
+}
+
 static bool CheckOldAppleWinVersion(void)
 {
 	TCHAR szOldAppleWinVersion[VERSIONSTRING_SIZE + 1];
@@ -1202,6 +1235,7 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 	bool bChangedDisplayResolution = false;
 	bool bSlot0LanguageCard = false;
 	bool bSlotEmpty[NUM_SLOTS] = {false,false,false,false,false,false,false,false};
+	bool bSlot7EmptyOnExit = false;
 	UINT bestWidth = 0, bestHeight = 0;
 	LPSTR szImageName_drive[NUM_DRIVES] = {NULL,NULL};
 	LPSTR szImageName_harddisk[NUM_HARDDISKS] = {NULL,NULL};
@@ -1214,6 +1248,8 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 	int newVideoStyleDisableMask = 0;
 	VideoRefreshRate_e newVideoRefreshRate = VR_NONE;
 	LPSTR szScreenshotFilename = NULL;
+	double clockMultiplier = 0.0;	// 0 => not set from cmd-line
+	eApple2Type model = A2TYPE_MAX;
 
 	while (*lpCmdLine)
 	{
@@ -1259,6 +1295,10 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 			if (strcmp(lpCmdLine, "empty") == 0)
 				bSlotEmpty[slot] = true;
 		}
+		else if (strcmp(lpCmdLine, "-s7-empty-on-exit") == 0)
+		{
+			bSlot7EmptyOnExit = true;
+		}
 		else if (strcmp(lpCmdLine, "-load-state") == 0)
 		{
 			lpCmdLine = GetCurrArg(lpNextArg);
@@ -1460,6 +1500,28 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 			szScreenshotFilename = GetCurrArg(lpNextArg);
 			lpNextArg = GetNextArg(lpNextArg);
 		}
+		else if (strcmp(lpCmdLine, "-clock-multiplier") == 0)
+		{
+			lpCmdLine = GetCurrArg(lpNextArg);
+			lpNextArg = GetNextArg(lpNextArg);
+			clockMultiplier = atof(lpCmdLine);
+		}
+		else if (strcmp(lpCmdLine, "-model") == 0)
+		{
+			lpCmdLine = GetCurrArg(lpNextArg);
+			lpNextArg = GetNextArg(lpNextArg);
+
+			if (strcmp(lpCmdLine, "apple2") == 0)
+				model = A2TYPE_APPLE2;
+			else if (strcmp(lpCmdLine, "apple2p") == 0)
+				model = A2TYPE_APPLE2PLUS;
+			else if (strcmp(lpCmdLine, "apple2e") == 0)
+				model = A2TYPE_APPLE2E;
+			else if (strcmp(lpCmdLine, "apple2ee") == 0)
+				model = A2TYPE_APPLE2EENHANCED;
+			else
+				LogFileOutput("-model: unsupported type: %s\n", lpCmdLine);
+		}
 		else if (_stricmp(lpCmdLine, "-50hz") == 0)	// (case-insensitive)
 		{
 			newVideoRefreshRate = VR_50HZ;
@@ -1580,6 +1642,9 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 		LoadConfiguration();
 		LogFileOutput("Main: LoadConfiguration()\n");
 
+		if (model != A2TYPE_MAX)
+			SetApple2Type(model);
+
 		if (newVideoType >= 0)
 		{
 			SetVideoType( (VideoType_e)newVideoType );
@@ -1594,6 +1659,9 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 			SetCurrentCLK6502();
 		}
 
+		UseClockMultiplier(clockMultiplier);
+		clockMultiplier = 0.0;
+
 		// Apply the memory expansion switches after loading the Apple II machine type
 #ifdef RAMWORKS
 		if (uRamWorksExPages)
@@ -1819,5 +1887,8 @@ int APIENTRY WinMain(HINSTANCE passinstance, HINSTANCE, LPSTR lpCmdLine, int)
 	if (g_hCustomRomF8 != INVALID_HANDLE_VALUE)
 		CloseHandle(g_hCustomRomF8);
 
+	if (bSlot7EmptyOnExit)
+		UnplugHardDiskControllerCard();
+
 	return 0;
 }
diff --git a/source/Disk.cpp b/source/Disk.cpp
index fdae09b5..2aefe359 100644
--- a/source/Disk.cpp
+++ b/source/Disk.cpp
@@ -1455,7 +1455,7 @@ bool Disk2InterfaceCard::UserSelectNewDiskImage(const int drive, LPCSTR pszFilen
 
 void __stdcall Disk2InterfaceCard::LoadWriteProtect(WORD, WORD, BYTE write, BYTE value, ULONG uExecutedCycles)
 {
-	_ASSERT(m_seqFunc.function == checkWriteProtAndInitWrite);
+	// NB. m_seqFunc.function == checkWriteProtAndInitWrite or shiftWrite (both OK)
 
 	// Don't change latch if drive off after 1 second drive-off delay (UTAIIe page 9-13)
 	// "DRIVES OFF forces the data register to hold its present state." (UTAIIe page 9-12)
@@ -1651,7 +1651,7 @@ void Disk2InterfaceCard::SetSequencerFunction(WORD addr)
 	if ((addr & 0xf) < 0xc)
 		return;
 
-	switch (addr & 3)
+	switch ((addr & 3) ^ 2)
 	{
 	case 0: m_seqFunc.writeMode = 0; break;	// $C08E,X (sequence addr A2 input)
 	case 1: m_seqFunc.writeMode = 1; break;	// $C08F,X (sequence addr A2 input)
diff --git a/source/LanguageCard.cpp b/source/LanguageCard.cpp
index 090835eb..f39a4141 100644
--- a/source/LanguageCard.cpp
+++ b/source/LanguageCard.cpp
@@ -103,7 +103,6 @@ BYTE __stdcall LanguageCardUnit::IO(WORD PC, WORD uAddr, BYTE bWrite, BYTE uValu
 	return bWrite ? 0 : MemReadFloatingBus(nExecutedCycles);
 }
 
-// GH#700: INC $C083/C08B (RMW) to write enable the LC
 bool LanguageCardUnit::IsOpcodeRMWabs(WORD addr)
 {
 	BYTE param1 = mem[(regs.pc - 2) & 0xffff];
@@ -111,7 +110,15 @@ bool LanguageCardUnit::IsOpcodeRMWabs(WORD addr)
 	if (param1 != (addr & 0xff) || param2 != 0xC0)
 		return false;
 
+	// GH#404, GH#700: INC $C083,X/C08B,X (RMW) to write enable the LC (any 6502/65C02/816)
 	BYTE opcode = mem[(regs.pc - 3) & 0xffff];
+	if (opcode == 0xFE && regs.x == 0)	// INC abs,x
+		return true;
+
+	// GH#700: INC $C083/C08B (RMW) to write enable the LC (65C02 only)
+	if (GetMainCpu() != CPU_65C02)
+		return false;
+
 	if (opcode == 0xEE ||	// INC abs
 		opcode == 0xCE ||	// DEC abs
 		opcode == 0x6E ||	// ROR abs
@@ -120,9 +127,8 @@ bool LanguageCardUnit::IsOpcodeRMWabs(WORD addr)
 		opcode == 0x0E)		// ASL abs
 		return true;
 
-	if ((GetMainCpu() == CPU_65C02) && (
-		opcode == 0x1C ||	// TRB abs
-		opcode == 0x0C))	// TSB abs
+	if (opcode == 0x1C ||	// TRB abs
+		opcode == 0x0C)		// TSB abs
 		return true;
 
 	return false;