diff --git a/src/emu/machine.c b/src/emu/machine.c
index d70161c697e..badd3ecc90e 100644
--- a/src/emu/machine.c
+++ b/src/emu/machine.c
@@ -1217,11 +1217,11 @@ astring &running_machine::nvram_filename(astring &result, device_t &device)
 		const char *software = image_parent_basename(&device);
 		if (software!=NULL && strlen(software)>0)
 		{
-			result.cat('\\').cat(software);
+			result.cat(PATH_SEPARATOR).cat(software);
 		}
 		astring tag(device.tag());
 		tag.del(0, 1).replacechr(':', '_');
-		result.cat('\\').cat(tag);
+		result.cat(PATH_SEPARATOR).cat(tag);
 	}
 	return result;
 }
diff --git a/src/osd/osdcore.h b/src/osd/osdcore.h
index ceb0cb45dbc..c7ae389db03 100644
--- a/src/osd/osdcore.h
+++ b/src/osd/osdcore.h
@@ -28,8 +28,12 @@
 
 /* Make sure we have a path separator (default to /) */
 #ifndef PATH_SEPARATOR
+#if defined(_WIN32) || defined (__OS2__)
+#define PATH_SEPARATOR          "\\"
+#else
 #define PATH_SEPARATOR          "/"
 #endif
+#endif
 
 /* flags controlling file access */
 #define OPEN_FLAG_READ          0x0001      /* open for read */
diff --git a/src/osd/sdl/sdlfile.c b/src/osd/sdl/sdlfile.c
index a010c02776a..e7293342ede 100644
--- a/src/osd/sdl/sdlfile.c
+++ b/src/osd/sdl/sdlfile.c
@@ -471,7 +471,7 @@ int osd_get_physical_drive_geometry(const char *filename, UINT32 *cylinders, UIN
 
 static int osd_is_path_separator(char c)
 {
-	return (c == '/') || (c == '\\');
+	return (c == PATHSEPCH) || (c == INVPATHSEPCH);
 }
 
 //============================================================
diff --git a/src/osd/windows/winfile.c b/src/osd/windows/winfile.c
index 9f02a547523..795840231b1 100644
--- a/src/osd/windows/winfile.c
+++ b/src/osd/windows/winfile.c
@@ -48,15 +48,10 @@ extern const char *winfile_ptty_identifier;
 
 file_error osd_open(const char *path, UINT32 openflags, osd_file **file, UINT64 *filesize)
 {
-	DWORD disposition, access, sharemode;
 	file_error filerr = FILERR_NONE;
-	const TCHAR *src;
-	DWORD upper;
-	TCHAR *t_path;
-	TCHAR *dst;
 
 	// convert path to TCHAR
-	t_path = tstring_from_utf8(path);
+	TCHAR *t_path = tstring_from_utf8(path);
 	if (t_path == NULL)
 	{
 		filerr = FILERR_OUT_OF_MEMORY;
@@ -89,17 +84,15 @@ file_error osd_open(const char *path, UINT32 openflags, osd_file **file, UINT64
 	(*file)->type = WINFILE_FILE;
 
 	// convert the path into something Windows compatible
-	dst = (*file)->filename;
-#if defined(SDLMAME_WIN32) || defined(SDLMAME_OS2)
-	for (src = t_path; *src != 0; src++)
-		*dst++ = (*src == '/') ? '\\' : *src;
-#else
-	for (src = t_path; *src != 0; src++)
-		*dst++ = *src;//(*src == '/') ? '\\' : *src;
-#endif
-	*dst++ = 0;
+	{
+		TCHAR *dst = (*file)->filename;
+		for (TCHAR const *src = t_path; *src != 0; src++)
+			*dst++ = *src;//(*src == '/') ? '\\' : *src;
+		*dst++ = 0;
+	}
 
 	// select the file open modes
+	DWORD disposition, access, sharemode;
 	if (openflags & OPEN_FLAG_WRITE)
 	{
 		disposition = (!is_path_to_physical_drive(path) && (openflags & OPEN_FLAG_CREATE)) ? CREATE_ALWAYS : OPEN_EXISTING;
@@ -149,6 +142,7 @@ file_error osd_open(const char *path, UINT32 openflags, osd_file **file, UINT64
 	}
 
 	// get the file size
+	DWORD upper;
 	*filesize = GetFileSize((*file)->handle, &upper);
 	*filesize |= (UINT64)upper << 32;
 
diff --git a/src/osd/windows/winprefix.h b/src/osd/windows/winprefix.h
index e506403e7b5..a705a2f7399 100644
--- a/src/osd/windows/winprefix.h
+++ b/src/osd/windows/winprefix.h
@@ -45,5 +45,3 @@ static __inline double log2(double x) { return log(x) * M_LOG2E; }
 #define min(x,y) fmin(x,y)
 #define max(x,y) fmax(x,y)
 #endif
-
-#define PATH_SEPARATOR      "\\"