diff --git a/sim_disk.c b/sim_disk.c
index f38c4b45..13e90aab 100644
--- a/sim_disk.c
+++ b/sim_disk.c
@@ -1335,7 +1335,7 @@ if (strchr (openmode, 'r'))
     DesiredAccess |= GENERIC_READ;
 if (strchr (openmode, 'w') || strchr (openmode, '+'))
     DesiredAccess |= GENERIC_WRITE;
-Handle = CreateFileA (rawdevicename, DesiredAccess, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_FLAG_RANDOM_ACCESS, NULL);
+Handle = CreateFileA (rawdevicename, DesiredAccess, FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_FLAG_RANDOM_ACCESS|FILE_FLAG_WRITE_THROUGH, NULL);
 if (Handle == INVALID_HANDLE_VALUE) {
     _set_errno_from_status (GetLastError ());
     return NULL;
@@ -1421,17 +1421,21 @@ static t_stat sim_os_disk_unload_raw (FILE *Disk)
 {
 #ifdef IOCTL_STORAGE_EJECT_MEDIA
 DWORD BytesReturned;
+uint32 Removable = FALSE;
 
-if (!DeviceIoControl((HANDLE)Disk,                      /* handle to disk */
-                     IOCTL_STORAGE_EJECT_MEDIA,         /* dwIoControlCode */
-                     NULL,                              /* lpInBuffer */
-                     0,                                 /* nInBufferSize */
-                     NULL,                              /* lpOutBuffer */
-                     0,                                 /* nOutBufferSize */
-                     (LPDWORD) &BytesReturned,          /* number of bytes returned */
-                     (LPOVERLAPPED) NULL)) {            /* OVERLAPPED structure */
-    _set_errno_from_status (GetLastError ());
-    return SCPE_IOERR;
+sim_os_disk_info_raw (Disk, NULL, &Removable);
+if (Removable) {
+    if (!DeviceIoControl((HANDLE)Disk,                  /* handle to disk */
+                         IOCTL_STORAGE_EJECT_MEDIA,     /* dwIoControlCode */
+                         NULL,                          /* lpInBuffer */
+                         0,                             /* nInBufferSize */
+                         NULL,                          /* lpOutBuffer */
+                         0,                             /* nOutBufferSize */
+                         (LPDWORD) &BytesReturned,      /* number of bytes returned */
+                         (LPOVERLAPPED) NULL)) {        /* OVERLAPPED structure */
+        _set_errno_from_status (GetLastError ());
+        return SCPE_IOERR;
+        }
     }
 return SCPE_OK;
 #else
@@ -1443,17 +1447,21 @@ static t_bool sim_os_disk_isavailable_raw (FILE *Disk)
 {
 #ifdef IOCTL_STORAGE_EJECT_MEDIA
 DWORD BytesReturned;
+uint32 Removable = FALSE;
 
-if (!DeviceIoControl((HANDLE)Disk,                      /* handle to disk */
-                     IOCTL_STORAGE_CHECK_VERIFY,        /* dwIoControlCode */
-                     NULL,                              /* lpInBuffer */
-                     0,                                 /* nInBufferSize */
-                     NULL,                              /* lpOutBuffer */
-                     0,                                 /* nOutBufferSize */
-                     (LPDWORD) &BytesReturned,          /* number of bytes returned */
-                     (LPOVERLAPPED) NULL)) {            /* OVERLAPPED structure */
-    _set_errno_from_status (GetLastError ());
-    return FALSE;
+sim_os_disk_info_raw (Disk, NULL, &Removable);
+if (Removable) {
+    if (!DeviceIoControl((HANDLE)Disk,                  /* handle to disk */
+                         IOCTL_STORAGE_CHECK_VERIFY,    /* dwIoControlCode */
+                         NULL,                          /* lpInBuffer */
+                         0,                             /* nInBufferSize */
+                         NULL,                          /* lpOutBuffer */
+                         0,                             /* nOutBufferSize */
+                         (LPDWORD) &BytesReturned,      /* number of bytes returned */
+                         (LPOVERLAPPED) NULL)) {        /* OVERLAPPED structure */
+        _set_errno_from_status (GetLastError ());
+        return FALSE;
+        }
     }
 #endif
 return TRUE;