diff --git a/frmts/aigrid/aigopen.c b/frmts/aigrid/aigopen.c
index 1da6b18b087d..6c03425db3fb 100644
--- a/frmts/aigrid/aigopen.c
+++ b/frmts/aigrid/aigopen.c
@@ -28,6 +28,9 @@
  ******************************************************************************
  *
  * $Log$
+ * Revision 1.18  2005/10/31 04:51:55  fwarmerdam
+ * upgraded to use large file API and GUInt32 for block offsets
+ *
  * Revision 1.17  2004/01/29 20:48:10  warmerda
  * Make sure that if a bare "w001001.adf" is given to AIGOpen() it will
  * work.  The name is changed to ".".
@@ -166,7 +169,7 @@ AIGInfo_t *AIGOpen( const char * pszInputName, const char * pszAccess )
 /* -------------------------------------------------------------------- */
     if( AIGReadBlockIndex( pszCoverName, psInfo ) != CE_None )
     {
-        VSIFClose( psInfo->fpGrid );
+        VSIFCloseL( psInfo->fpGrid );
         
         CPLFree( psInfo );
         return NULL;
@@ -177,7 +180,7 @@ AIGInfo_t *AIGOpen( const char * pszInputName, const char * pszAccess )
 /* -------------------------------------------------------------------- */
     if( AIGReadBounds( pszCoverName, psInfo ) != CE_None )
     {
-        VSIFClose( psInfo->fpGrid );
+        VSIFCloseL( psInfo->fpGrid );
         
         CPLFree( psInfo );
         return NULL;
@@ -188,7 +191,7 @@ AIGInfo_t *AIGOpen( const char * pszInputName, const char * pszAccess )
 /* -------------------------------------------------------------------- */
     if( AIGReadStatistics( pszCoverName, psInfo ) != CE_None )
     {
-        VSIFClose( psInfo->fpGrid );
+        VSIFCloseL( psInfo->fpGrid );
         
         CPLFree( psInfo );
         return NULL;
@@ -290,7 +293,7 @@ CPLErr AIGReadFloatTile( AIGInfo_t * psInfo, int nBlockXOff, int nBlockYOff,
 void AIGClose( AIGInfo_t * psInfo )
 
 {
-    VSIFClose( psInfo->fpGrid );
+    VSIFCloseL( psInfo->fpGrid );
 
     CPLFree( psInfo->panBlockOffset );
     CPLFree( psInfo->panBlockSize );
@@ -310,7 +313,7 @@ FILE *AIGLLOpen( const char *pszFilename, const char *pszAccess )
 {
     FILE	*fp;
 
-    fp = VSIFOpen( pszFilename, pszAccess );
+    fp = VSIFOpenL( pszFilename, pszAccess );
     if( fp == NULL )
     {
         char *pszUCFilename = CPLStrdup(pszFilename);
@@ -323,7 +326,7 @@ FILE *AIGLLOpen( const char *pszFilename, const char *pszAccess )
             pszUCFilename[i] = (char) toupper(pszUCFilename[i]);
         }
         
-        fp = VSIFOpen( pszUCFilename, pszAccess );
+        fp = VSIFOpenL( pszUCFilename, pszAccess );
 
         CPLFree( pszUCFilename );
     }
diff --git a/frmts/aigrid/aigrid.h b/frmts/aigrid/aigrid.h
index b46fd3bb83bf..377443a8117f 100644
--- a/frmts/aigrid/aigrid.h
+++ b/frmts/aigrid/aigrid.h
@@ -28,6 +28,9 @@
  ******************************************************************************
  *
  * $Log$
+ * Revision 1.13  2005/10/31 04:51:55  fwarmerdam
+ * upgraded to use large file API and GUInt32 for block offsets
+ *
  * Revision 1.12  2002/11/11 18:29:03  warmerda
  * added AIGLLOpen() to support upper case names too
  *
@@ -84,7 +87,7 @@ typedef struct {
     /* Private information */
     
     int		nBlocks;
-    int		*panBlockOffset;
+    GUInt32	*panBlockOffset;
     int		*panBlockSize;
 
     FILE	*fpGrid;	/* the w001001.adf file */
@@ -128,7 +131,7 @@ typedef struct {
 /*      Private APIs                                                    */
 /* ==================================================================== */
 
-CPLErr AIGReadBlock( FILE * fp, int nBlockOffset, int nBlockSize,
+CPLErr AIGReadBlock( FILE * fp, GUInt32 nBlockOffset, int nBlockSize,
                      int nBlockXSize, int nBlockYSize, GInt32 * panData,
                      int nCellType );
 
diff --git a/frmts/aigrid/gridlib.c b/frmts/aigrid/gridlib.c
index cccd56aca2e7..2fd1813b1a21 100644
--- a/frmts/aigrid/gridlib.c
+++ b/frmts/aigrid/gridlib.c
@@ -28,6 +28,9 @@
  ******************************************************************************
  *
  * $Log$
+ * Revision 1.24  2005/10/31 04:51:55  fwarmerdam
+ * upgraded to use large file API and GUInt32 for block offsets
+ *
  * Revision 1.23  2004/04/05 19:59:05  warmerda
  * Fixed 0x01 support, wasn't including nMin.
  *
@@ -582,7 +585,7 @@ CPLErr AIGProcessBlock( GByte *pabyCur, int nDataSize, int nMin, int nMagic,
 /*      Read a single block of integer grid data.                       */
 /************************************************************************/
 
-CPLErr AIGReadBlock( FILE * fp, int nBlockOffset, int nBlockSize,
+CPLErr AIGReadBlock( FILE * fp, GUInt32 nBlockOffset, int nBlockSize,
                      int nBlockXSize, int nBlockYSize,
                      GInt32 *panData, int nCellType )
 
@@ -607,8 +610,8 @@ CPLErr AIGReadBlock( FILE * fp, int nBlockOffset, int nBlockSize,
 /*      Read the block into memory.                                     */
 /* -------------------------------------------------------------------- */
     pabyRaw = (GByte *) CPLMalloc(nBlockSize+2);
-    if( VSIFSeek( fp, nBlockOffset, SEEK_SET ) != 0 
-        || VSIFRead( pabyRaw, nBlockSize+2, 1, fp ) != 1 )
+    if( VSIFSeekL( fp, nBlockOffset, SEEK_SET ) != 0 
+        || VSIFReadL( pabyRaw, nBlockSize+2, 1, fp ) != 1 )
     {
         memset( panData, 0, nBlockXSize*nBlockYSize*4 );
         CPLError( CE_Failure, CPLE_AppDefined, 
@@ -805,9 +808,9 @@ CPLErr AIGReadHeader( const char * pszCoverName, AIGInfo_t * psInfo )
 /*      long.                                                           */
 /* -------------------------------------------------------------------- */
 
-    VSIFRead( abyData, 1, 308, fp );
+    VSIFReadL( abyData, 1, 308, fp );
 
-    VSIFClose( fp );
+    VSIFCloseL( fp );
     
 /* -------------------------------------------------------------------- */
 /*      Read the block size information.                                */
@@ -872,8 +875,8 @@ CPLErr AIGReadBlockIndex( const char * pszCoverName, AIGInfo_t * psInfo )
 /* -------------------------------------------------------------------- */
 /*      Get the file length (in 2 byte shorts)                          */
 /* -------------------------------------------------------------------- */
-    VSIFSeek( fp, 24, SEEK_SET );
-    VSIFRead( &nValue, 1, 4, fp );
+    VSIFSeekL( fp, 24, SEEK_SET );
+    VSIFReadL( &nValue, 1, 4, fp );
 
     nLength = CPL_MSBWORD32(nValue) * 2;
 
@@ -883,15 +886,15 @@ CPLErr AIGReadBlockIndex( const char * pszCoverName, AIGInfo_t * psInfo )
 /* -------------------------------------------------------------------- */
     psInfo->nBlocks = (nLength-100) / 8;
     panIndex = (GUInt32 *) CPLMalloc(psInfo->nBlocks * 8);
-    VSIFSeek( fp, 100, SEEK_SET );
-    VSIFRead( panIndex, 8, psInfo->nBlocks, fp );
+    VSIFSeekL( fp, 100, SEEK_SET );
+    VSIFReadL( panIndex, 8, psInfo->nBlocks, fp );
 
-    VSIFClose( fp );
+    VSIFCloseL( fp );
 
 /* -------------------------------------------------------------------- */
 /*	Allocate AIGInfo block info arrays.				*/
 /* -------------------------------------------------------------------- */
-    psInfo->panBlockOffset = (int *) CPLMalloc(4 * psInfo->nBlocks);
+    psInfo->panBlockOffset = (GUInt32 *) CPLMalloc(4 * psInfo->nBlocks);
     psInfo->panBlockSize = (int *) CPLMalloc(4 * psInfo->nBlocks);
 
 /* -------------------------------------------------------------------- */
@@ -944,9 +947,9 @@ CPLErr AIGReadBounds( const char * pszCoverName, AIGInfo_t * psInfo )
 /* -------------------------------------------------------------------- */
 /*      Get the contents - four doubles.                                */
 /* -------------------------------------------------------------------- */
-    VSIFRead( adfBound, 1, 32, fp );
+    VSIFReadL( adfBound, 1, 32, fp );
 
-    VSIFClose( fp );
+    VSIFCloseL( fp );
 
 #ifdef CPL_LSB
     CPL_SWAPDOUBLE(adfBound+0);
@@ -1004,9 +1007,9 @@ CPLErr AIGReadStatistics( const char * pszCoverName, AIGInfo_t * psInfo )
 /* -------------------------------------------------------------------- */
 /*      Get the contents - four doubles.                                */
 /* -------------------------------------------------------------------- */
-    VSIFRead( adfStats, 1, 32, fp );
+    VSIFReadL( adfStats, 1, 32, fp );
 
-    VSIFClose( fp );
+    VSIFCloseL( fp );
 
 #ifdef CPL_LSB
     CPL_SWAPDOUBLE(adfStats+0);