diff --git a/README.md b/README.md
index a8de267..e45e716 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 VBinDiff - Visual Binary Diff
 =============================
 
-[Visual Binary Diff (VBinDiff)](http://www.cjmweb.net/vbindiff/) displays files in hexadecimal and ASCII (or EBCDIC).  It can also display two files at once, and highlight the differences between them.  Unlike diff, it works well with large files (up to 4 GB).
+[Visual Binary Diff (VBinDiff)](http://www.cjmweb.net/vbindiff/) displays files in hexadecimal and ASCII (or EBCDIC).  It can also display two files at once, and highlight the differences between them.  Unlike diff, it works well with large files (up to 64 GB).
 
 VBinDiff was inspired by the Compare Files function of the [ProSel utilities by Glen Bredon](http://www.apple2.org.za/gswv/USA2WUG/Glen.Bredon.In.Memoriam/A2.Software/), for the [Apple II](https://en.wikipedia.org/wiki/Apple_II).  When I couldn't find a similar utility for the PC, I wrote it myself.
 
diff --git a/tools/ReadMe.tt b/tools/ReadMe.tt
index cd0a433..4f55e57 100644
--- a/tools/ReadMe.tt
+++ b/tools/ReadMe.tt
@@ -60,7 +60,7 @@ $stash->set(section => sub {
 Visual Binary Diff (VBinDiff) displays files in hexadecimal and ASCII
 (or EBCDIC).  It can also display two files at once, and highlight the
 differences between them.  Unlike diff, it works well with large files
-(up to 4 GB).
+(up to 64 GB).
 
 VBinDiff was inspired by the Compare Files function of the ProSel
 utilities by Glen Bredon, for the Apple II.  When I couldn't find a
diff --git a/tools/vbindiff.pod.tt b/tools/vbindiff.pod.tt
index 41f609f..d1eeaf4 100644
--- a/tools/vbindiff.pod.tt
+++ b/tools/vbindiff.pod.tt
@@ -39,7 +39,7 @@ B<vbindiff> I<file1> [ I<file2> ]
 Visual Binary Diff (VBinDiff) displays files in hexadecimal and ASCII
 (or EBCDIC).  It can also display two files at once, and highlight
 the differences between them.  Unlike B<diff>, it works well with
-large files (up to 4 GB).
+large files (up to 64 GB).
 
 =head2 Viewing files
 
diff --git a/vbindiff.cpp b/vbindiff.cpp
index d762e77..d24b2ab 100644
--- a/vbindiff.cpp
+++ b/vbindiff.cpp
@@ -114,8 +114,8 @@ const Command  cmUseBottom    = 11;
 const Command  cmToggleASCII  = 12;
 const Command  cmFind         = 16; // Commands 16-19
 
-const short  leftMar  = 11;     // Starting column of hex display
-const short  leftMar2 = 61;     // Starting column of ASCII display
+const short  leftMar  = 13;     // Starting column of hex display
+const short  leftMar2 = 63;     // Starting column of ASCII display
 
 const int  lineWidth = 16;      // Number of bytes displayed per line
 
@@ -460,7 +460,7 @@ void FileDisplay::display()
   FPos  lineOffset = offset;
 
   short i,j,index,lineLength;
-  char  buf[lineWidth + lineWidth/8 + 1];
+  char  buf[lineWidth + lineWidth/8];
   buf[sizeof(buf)-1] = '\0';
 
   char  buf2[screenWidth+1];
@@ -472,7 +472,7 @@ void FileDisplay::display()
 //    cerr << i << '\n';
     char*  str = buf2;
     str +=
-      sprintf(str, "%04X %04X:",Word(lineOffset>>16),Word(lineOffset&0xFFFF));
+      sprintf(str, "%01X %04X %04X:",Word(lineOffset>>32),Word(lineOffset>>16),Word(lineOffset&0xFFFF));
 
     lineLength  = min(lineWidth, bufContents - i*lineWidth);
 
@@ -1548,9 +1548,9 @@ Command getCommand()
 
 void gotoPosition(Command cmd)
 {
-  positionInWin(cmd, inWidth+2, " Goto ");
+  positionInWin(cmd, inWidth+3, " Goto ");
 
-  const int  maxLen = inWidth-2;
+  const int  maxLen = inWidth-1;
   char  buf[maxLen+1];
 
   getString(buf, maxLen, positionHistory, hexDigits, true);
@@ -1558,7 +1558,7 @@ void gotoPosition(Command cmd)
   if (!buf[0])
     return;
 
-  FPos  pos = strtoul(buf, NULL, 16);
+  FPos  pos = _strtoui64(buf, NULL, 16);
 
   if (cmd & cmgGotoTop)
     file1.moveTo(pos);