diff --git a/harbour/ChangeLog b/harbour/ChangeLog
index b9223cf209..af09a0a685 100644
--- a/harbour/ChangeLog
+++ b/harbour/ChangeLog
@@ -1,3 +1,10 @@
+19991106-01:30 EDT David G. Holm <dholm@jsd-llc.com>
+
+   * include/filesys.h
+   * source/rtl/filesys.c
+     ! Proper optimization implemented for hb_fsReadLarge() and
+       hb_fsWriteLarge(), as suggested by Victor Szel.
+
 19991105-23:30 EDT David G. Holm <dholm@jsd-llc.com>
 
    * source/rtl/filesys.c
diff --git a/harbour/include/filesys.h b/harbour/include/filesys.h
index b1ee2d56c4..3aa7b25704 100644
--- a/harbour/include/filesys.h
+++ b/harbour/include/filesys.h
@@ -105,6 +105,7 @@ extern BOOL     hb_fsLock       ( FHANDLE hFileHandle, ULONG ulStart,
 extern BOOL     hb_fsMkDir      ( BYTE * pDirName );
 extern FHANDLE  hb_fsOpen       ( BYTE * pFilename, USHORT uiFlags );
 extern USHORT   hb_fsRead       ( FHANDLE hFileHandle, BYTE * pBuff, USHORT ulCount );
+extern ULONG    hb_fsReadLarge  ( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount );
 extern BOOL     hb_fsRmDir      ( BYTE * pDirName );
 extern int      hb_fsRename     ( BYTE * pOldName, BYTE * pNewName );
 extern ULONG    hb_fsSeek       ( FHANDLE hFileHandle, LONG lOffset, USHORT uiMode );
@@ -114,17 +115,7 @@ extern void     hb_fsSetDevRaw  ( FHANDLE hFileHandle );
 extern void     hb_fsSetDevText ( FHANDLE hFileHandle );
 extern void     hb_fsSetError   ( USHORT uiError );
 extern USHORT   hb_fsWrite      ( FHANDLE hFileHandle, BYTE * pBuff, USHORT ulCount );
-
-#if UINT_MAX == ULONG_MAX
-   /* NOTE: hb_fsRead/hb_fsWrite can work with ULONG data blocks */
-   #define hb_fsReadLarge   hb_fsRead
-   #define hb_fsWriteLarge  hb_fsWrite
-#else
-   /* NOTE: otherwise, the extended version of the functions
-            will be used to copy and/or set ULONG data blocks */
-extern ULONG    hb_fsReadLarge  ( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount );
 extern ULONG    hb_fsWriteLarge ( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount );
-#endif
 
 extern PHB_FNAME hb_fsFNameSplit ( char * szFilename ); /* Split given filename into path, name and extension */
 extern char *    hb_fsFNameMerge ( char * szFileName, PHB_FNAME pFileName ); /* This function joins path, name and extension into a string with a filename */
diff --git a/harbour/source/rtl/filesys.c b/harbour/source/rtl/filesys.c
index 3b9b04274e..5a7bca98d2 100644
--- a/harbour/source/rtl/filesys.c
+++ b/harbour/source/rtl/filesys.c
@@ -208,6 +208,12 @@ static USHORT s_uiErrorLast = 0;
    #define PATH_MAX 256
 #endif
 
+#if UINT_MAX == ULONG_MAX
+   #define HB_FS_LARGE_OPTIMIZED
+#else
+   #define LARGE_MAX ( UINT_MAX - 1L )
+#endif
+
 extern int rename( const char *, const char * );
 
 /* Convert HARBOUR flags to IO subsystem flags */
@@ -558,23 +564,24 @@ USHORT  hb_fsWrite( FHANDLE hFileHandle, BYTE * pBuff, USHORT uiCount )
    return uiWritten;
 }
 
-#if UINT_MAX != ULONG_MAX
-
-#define LARGE_MAX ( UINT_MAX - 1L )
-
 ULONG   hb_fsReadLarge( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount )
 {
    ULONG ulRead = 0;
+#if ! defined(HB_FS_LARGE_OPTIMIZED)
    ULONG ulLeftToRead = ulCount;
    USHORT uiToRead;
    USHORT uiRead;
    BYTE * pPtr = pBuff;
+#endif
 
    HB_TRACE(HB_TR_DEBUG, ("hb_fsReadLarge(%p, %p, %lu)", hFileHandle, pBuff, ulCount));
 
 #if defined(HAVE_POSIX_IO) || defined(_MSC_VER) || defined(__MINGW32__)
 
    errno = 0;
+ #if defined(HB_FS_LARGE_OPTIMIZED)
+   ulRead = read( hFileHandle, pBuff, ulCount );
+ #else
    while( ulLeftToRead )
    {
       /* Determine how much to read this time */
@@ -598,6 +605,7 @@ ULONG   hb_fsReadLarge( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount )
       ulRead += ( ULONG ) uiRead;
       pPtr += uiRead;
    }
+  #endif
    s_uiErrorLast = errno;
 
 #else
@@ -612,17 +620,23 @@ ULONG   hb_fsReadLarge( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount )
 ULONG   hb_fsWriteLarge( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount )
 {
    ULONG ulWritten = 0;
+#if ! defined(HB_FS_LARGE_OPTIMIZED)
    ULONG ulLeftToWrite = ulCount;
    USHORT uiToWrite;
    USHORT uiWritten;
    BYTE * pPtr = pBuff;
+#endif
 
    HB_TRACE(HB_TR_DEBUG, ("hb_fsWriteLarge(%p, %p, %lu)", hFileHandle, pBuff, ulCount));
 
 #if defined(HAVE_POSIX_IO) || defined(_MSC_VER) || defined(__MINGW32__)
 
    errno = 0;
-   if( ulCount ) while( ulLeftToWrite )
+   if( ulCount )
+  #if defined(HB_FS_LARGE_OPTIMIZED)
+   ulWritten = write( hFileHandle, pBuff, ulCount );
+  #else
+   while( ulLeftToWrite )
    {
       /* Determine how much to write this time */
       if( ulLeftToWrite > ( ULONG ) INT_MAX )
@@ -645,6 +659,7 @@ ULONG   hb_fsWriteLarge( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount )
       ulWritten += ( ULONG ) uiWritten;
       pPtr += uiWritten;
    }
+  #endif
    else ftruncate( hFileHandle, tell( hFileHandle ) );
    s_uiErrorLast = errno;
 
@@ -657,8 +672,6 @@ ULONG   hb_fsWriteLarge( FHANDLE hFileHandle, BYTE * pBuff, ULONG ulCount )
    return ulWritten;
 }
 
-#endif
-
 ULONG   hb_fsSeek( FHANDLE hFileHandle, LONG lOffset, USHORT uiFlags )
 {
    ULONG ulPos;