Moved external FDC DLL code to Ext1770.cpp

Src/BeebEm.vcxproj

@@ -179,6 +179,7 @@
     <ClCompile Include="AviWriter.cpp" />
     <ClCompile Include="Bcd.cpp" />
     <ClCompile Include="BeebMem.cpp" />
+    <ClCompile Include="Ext1770.cpp" />
     <ClCompile Include="Sound.cpp" />
     <ClCompile Include="BeebWin.cpp" />
     <ClCompile Include="BeebWinDx.cpp" />

Src/BeebEm.vcxproj.filters

@@ -114,6 +114,9 @@
     <ClCompile Include="ExportFileDialog.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="Ext1770.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="FileDialog.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>

Src/BeebWin.cpp

@@ -120,11 +120,6 @@ LEDType LEDs;
 
 LEDColour DiscLedColour = LEDColour::Red;
 
-// FDC Board extension DLL variables
-HMODULE hFDCBoard;
-EDCB ExtBoard={0,0,NULL};
-char FDCDLL[256]={0};
-
 const char *WindowTitle = "BeebEm - BBC Model B / Master 128 Emulator";
 
 /****************************************************************************/
@@ -3744,8 +3739,10 @@ void BeebWin::HandleCommand(UINT MenuID)
 	case ID_8271:
 		KillDLLs();
 		NativeFDC = true;
+
 		CheckMenuItem(ID_8271, true);
 		CheckMenuItem(ID_FDC_DLL, false);
+
 		if (MachineType != Model::Master128)
 		{
 			char CfgName[20];

Src/BeebWinDx.cpp

@@ -36,9 +36,6 @@ Boston, MA  02110-1301, USA.
 
 typedef HRESULT (WINAPI* LPDIRECTDRAWCREATE)(GUID FAR *lpGUID, LPDIRECTDRAW FAR *lplpDD, IUnknown FAR *pUnkOuter);
 
-extern HMODULE hFDCBoard;
-extern EDCB ExtBoard;
-
 /****************************************************************************/
 void BeebWin::InitDX()
 {
@@ -855,11 +852,13 @@ void BeebWin::DisplayClientAreaText(HDC hdc)
 /****************************************************************************/
 void BeebWin::DisplayFDCBoardInfo(HDC hDC, int x, int y)
 {
-	if (DisplayCycles > 0 && hFDCBoard != NULL)
+	if (DisplayCycles > 0 && HasFDCBoard())
 	{
+		const char* BoardName = GetFDCBoardName();
+
 		SetBkMode(hDC, TRANSPARENT);
 		SetTextColor(hDC, 0x808080);
-		TextOut(hDC, x, y, ExtBoard.BoardName, (int)strlen(ExtBoard.BoardName));
+		TextOut(hDC, x, y, BoardName, (int)strlen(BoardName));
 	}
 }
 

Src/BeebWinIo.cpp

@@ -63,17 +63,6 @@ using std::max;
 
 using namespace Gdiplus;
 
-extern EDCB ExtBoard;
-extern char FDCDLL[256];
-extern HMODULE hFDCBoard;
-
-typedef void (*lGetBoardProperties)(struct DriveControlBlock *);
-typedef unsigned char (*lSetDriveControl)(unsigned char);
-typedef unsigned char (*lGetDriveControl)(unsigned char);
-lGetBoardProperties PGetBoardProperties;
-lSetDriveControl PSetDriveControl;
-lGetDriveControl PGetDriveControl;
-
 /****************************************************************************/
 
 void BeebWin::SetImageName(const char *DiscName, int Drive, DiscType Type)
@@ -468,8 +457,9 @@ void BeebWin::SelectFDC()
 		}
 		else
 		{
-			strcpy(FDCDLL,FileName);
+			strcpy(FDCDLL, FileName);
 		}
+
 		LoadFDC(FDCDLL, true);
 	}
 }
@@ -1103,80 +1093,74 @@ void BeebWin::LoadFDC(char *DLLName, bool save)
 	char CfgName[20];
 	sprintf(CfgName, "FDCDLL%d", static_cast<int>(MachineType));
 
-	if (hFDCBoard != nullptr)
-	{
-		FreeLibrary(hFDCBoard);
-		hFDCBoard = nullptr;
-	}
+	Ext1770Reset();
 
 	NativeFDC = true;
 
-	if (DLLName == NULL) {
+	if (DLLName == nullptr)
+	{
 		if (!m_Preferences.GetStringValue(CfgName, FDCDLL))
-			strcpy(FDCDLL,"None");
+			strcpy(FDCDLL, "None");
 		DLLName = FDCDLL;
 	}
 
-	if (strcmp(DLLName, "None")) {
+	if (strcmp(DLLName, "None") != 0)
+	{
 		char path[_MAX_PATH];
 		strcpy(path, DLLName);
 		GetDataPath(m_AppPath, path);
 
-		hFDCBoard=LoadLibrary(path);
-		if (hFDCBoard==NULL) {
+		Ext1770Result Result = Ext1770Init(path);
+
+		if (Result == Ext1770Result::Success)
+		{
+			NativeFDC = false; // at last, a working DLL!
+		}
+		else if (Result == Ext1770Result::LoadFailed)
+		{
 			Report(MessageType::Error, "Unable to load FDD Extension Board DLL\nReverting to native 8271");
 			strcpy(DLLName, "None");
 		}
-		else {
-			PGetBoardProperties=(lGetBoardProperties) GetProcAddress(hFDCBoard,"GetBoardProperties");
-			PSetDriveControl=(lSetDriveControl) GetProcAddress(hFDCBoard,"SetDriveControl");
-			PGetDriveControl=(lGetDriveControl) GetProcAddress(hFDCBoard,"GetDriveControl");
-			if ((PGetBoardProperties==NULL) || (PSetDriveControl==NULL) || (PGetDriveControl==NULL)) {
-				Report(MessageType::Error, "Invalid FDD Extension Board DLL\nReverting to native 8271");
-				strcpy(DLLName, "None");
-			}
-			else {
-				PGetBoardProperties(&ExtBoard);
-				EFDCAddr=ExtBoard.FDCAddress;
-				EDCAddr=ExtBoard.DCAddress;
-				NativeFDC = false; // at last, a working DLL!
-				InvertTR00=ExtBoard.TR00_ActiveHigh;
-			}
-		} 
+		else // if (Result == InvalidDLL)
+		{
+			Report(MessageType::Error, "Invalid FDD Extension Board DLL\nReverting to native 8271");
+			strcpy(DLLName, "None");
+		}
 	}
 
 	if (save)
+	{
 		m_Preferences.SetStringValue(CfgName, DLLName);
+	}
 
 	// Set menu options
 	CheckMenuItem(ID_8271, NativeFDC);
 	CheckMenuItem(ID_FDC_DLL, !NativeFDC);
 
-	DisplayCycles=7000000;
+	DisplayCycles = 7000000;
+
 	if (NativeFDC || MachineType == Model::Master128)
-		DisplayCycles=0;
+		DisplayCycles = 0;
 }
 
 void BeebWin::KillDLLs()
 {
-	if (hFDCBoard != nullptr)
-	{
-		FreeLibrary(hFDCBoard);
-		hFDCBoard = nullptr;
-	}
+	Ext1770Reset();
 }
 
-void BeebWin::SetDriveControl(unsigned char value) {
-	// This takes a value from the mem/io decoder, as written by the cpu, runs it through the
-	// DLL's translator, then sends it on to the 1770 FDC in master 128 form.
-	WriteFDCControlReg(PSetDriveControl(value));
+void BeebWin::SetDriveControl(unsigned char Value)
+{
+	// This takes a value from the mem/io decoder, as written by the CPU,
+	// runs it through the DLL's translator, then sends it on to the
+	// 1770 FDC in Master 128 form.
+	WriteFDCControlReg(::SetDriveControl(Value));
 }
 
-unsigned char BeebWin::GetDriveControl(void) {
-	// Same as above, but in reverse, i.e. reading
-	unsigned char temp=ReadFDCControlReg();
-	unsigned char temp2=PGetDriveControl(temp);
-	return(temp2);
+unsigned char BeebWin::GetDriveControl()
+{
+	// Same as above, but in reverse, i.e., reading.
+	unsigned char temp = ReadFDCControlReg();
+	return ::GetDriveControl(temp);
 }
 
 /****************************************************************************/

Src/Disc1770.cpp

@@ -31,6 +31,7 @@ Written by Richard Gellman - Feb 2001
 #include "Disc1770.h"
 #include "6502core.h"
 #include "DiscInfo.h"
+#include "Ext1770.h"
 #include "FileUtils.h"
 #include "Log.h"
 #include "Main.h"
@@ -1265,7 +1266,6 @@ bool CreateADFSImage(const char *FileName, int Tracks) {
 
 void Save1770UEF(FILE *SUEF)
 {
-	extern char FDCDLL[256];
 	char blank[256];
 	memset(blank,0,256);
 
@@ -1341,7 +1341,6 @@ void Save1770UEF(FILE *SUEF)
 
 void Load1770UEF(FILE *SUEF, int Version)
 {
-	extern char FDCDLL[256];
 	char FileName[256];
 	bool Loaded = false;
 	bool LoadFailed = false;

Src/Ext1770.cpp

@@ -0,0 +1,125 @@
+/****************************************************************
+BeebEm - BBC Micro and Master 128 Emulator
+Copyright (C) 2001  Richard Gellman
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License, or (at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public
+License along with this program; if not, write to the Free
+Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+Boston, MA  02110-1301, USA.
+****************************************************************/
+
+#include <windows.h>
+
+#include "Ext1770.h"
+#include "BeebMem.h"
+#include "Disc1770.h"
+
+/*--------------------------------------------------------------------------*/
+
+struct DriveControlBlock
+{
+	int FDCAddress; // 1770 FDC chip address
+	int DCAddress; // Drive Control Register Address
+	const char *BoardName; // FDC Board name
+	bool TR00_ActiveHigh; // Set true if the TR00 input is Active High
+};
+
+// FDC Board extension DLL variables
+char FDCDLL[256] = { 0 };
+
+static HMODULE hFDCBoard = nullptr;
+static DriveControlBlock ExtBoard = { 0, 0, nullptr };
+
+typedef void (*GetBoardPropertiesFunc)(struct DriveControlBlock *);
+typedef unsigned char (*SetDriveControlFunc)(unsigned char);
+typedef unsigned char (*GetDriveControlFunc)(unsigned char);
+
+GetBoardPropertiesFunc PGetBoardProperties;
+SetDriveControlFunc PSetDriveControl;
+GetDriveControlFunc PGetDriveControl;
+
+/*--------------------------------------------------------------------------*/
+
+void Ext1770Reset()
+{
+	if (hFDCBoard != nullptr)
+	{
+		FreeLibrary(hFDCBoard);
+		hFDCBoard = nullptr;
+	}
+
+	PGetBoardProperties = nullptr;
+	PSetDriveControl = nullptr;
+	PGetDriveControl = nullptr;
+}
+
+/*--------------------------------------------------------------------------*/
+
+Ext1770Result Ext1770Init(const char *FileName)
+{
+	hFDCBoard = LoadLibrary(FileName);
+
+	if (hFDCBoard == nullptr)
+	{
+		return Ext1770Result::LoadFailed;
+	}
+
+	PGetBoardProperties = (GetBoardPropertiesFunc)GetProcAddress(hFDCBoard, "GetBoardProperties");
+	PSetDriveControl = (SetDriveControlFunc)GetProcAddress(hFDCBoard, "SetDriveControl");
+	PGetDriveControl = (GetDriveControlFunc)GetProcAddress(hFDCBoard, "GetDriveControl");
+
+	if (PGetBoardProperties == nullptr ||
+	    PSetDriveControl == nullptr ||
+	    PGetDriveControl == nullptr)
+	{
+		Ext1770Reset();
+
+		return Ext1770Result::InvalidDLL;
+	}
+
+	PGetBoardProperties(&ExtBoard);
+
+	EFDCAddr = ExtBoard.FDCAddress;
+	EDCAddr = ExtBoard.DCAddress;
+	InvertTR00 = ExtBoard.TR00_ActiveHigh;
+
+	return Ext1770Result::Success;
+}
+
+/*--------------------------------------------------------------------------*/
+
+bool HasFDCBoard()
+{
+	return hFDCBoard != nullptr;
+}
+
+/*--------------------------------------------------------------------------*/
+
+const char* GetFDCBoardName()
+{
+	return ExtBoard.BoardName;
+}
+
+/*--------------------------------------------------------------------------*/
+
+unsigned char GetDriveControl(unsigned char Value)
+{
+	return PGetDriveControl(Value);
+}
+
+/*--------------------------------------------------------------------------*/
+
+unsigned char SetDriveControl(unsigned char Value)
+{
+	return PSetDriveControl(Value);
+}