diff --git a/src/rntuple.cpp b/src/rntuple.cpp
index 42ac0d2..0715235 100644
--- a/src/rntuple.cpp
+++ b/src/rntuple.cpp
@@ -369,7 +369,7 @@ Section find_section(App_State &app, u64 off, i64 hilite_cluster = -1)
   b8 hilite = false;
 
   // TFile start
-  if (off <= tdata.root_file_header_size) return { Sec_TFile_Header, { 0, tdata.root_file_header_size }, 0, hilite };
+  if (off < tdata.root_file_header_size) return { Sec_TFile_Header, { 0, tdata.root_file_header_size }, 0, hilite };
   if (tdata.rng_root_file_obj.start <= off && off < tdata.rng_root_file_obj.end())   return { Sec_TFile_Object, tdata.rng_root_file_obj, 0, hilite };
   if (tdata.rng_root_file_info.start <= off && off < tdata.rng_root_file_info.end()) return { Sec_TFile_Info, tdata.rng_root_file_info, 0, hilite };
   if (tdata.rng_root_file_free.start <= off && off < tdata.rng_root_file_free.end()) return { Sec_TFile_FreeList, tdata.rng_root_file_free, 0, hilite };
@@ -445,51 +445,160 @@ struct Sec_Hover_Info {
   String8_Node *desc;
 };
 
+template <typename T> void hover_postproc_val(T &) {}
+template <> void hover_postproc_val(u16 &x) { x = bswap_16(x); }
+template <> void hover_postproc_val(u32 &x) { x = bswap_32(x); }
+template <> void hover_postproc_val(u64 &x) { x = bswap_64(x); }
+
+template <typename T> 
+String8_Node *hover_display_val(Arena *arena, String8_Node *prev, const char *fmt, T val)
+{
+  hover_postproc_val(val);
+  return push_str8_node(arena, prev, fmt, val);
+}
+
+internal
+String8_Node *hover_display_datetime_str(Arena *arena, String8_Node *prev, const char *fmt_pre, u32 datetime)
+{
+  hover_postproc_val(datetime);
+  
+  // datetime:
+  // year (6b) | month (4b) | day (5b) | hour (5b) | min (6b) | sec (6b)
+  u32 year = (datetime >> 26) - 1900 + 1995;
+  u32 month = ((datetime & 0x3ff'ffff) >> 22) - 1;
+  u32 day = (datetime & 0x3f'ffff) >> 17;
+  u32 hour = (datetime & 0x1'ffff) >> 12;
+  u32 min = (datetime & 0xfff) >> 6;
+  u32 sec = datetime & 0x3f;
+  return push_str8_node(arena, prev, "%s%u/%02u/%02u %02u:%02u:%02u", fmt_pre, year, month, day, hour, min, sec);
+}
+
+struct Try_Sec_Hover_Fn {
+  u64 start;
+  u64 roff;
+  const u8 *data;
+  Arena *arena;
+  Sec_Hover_Info &info;
+  u64 &cur_field_off;
+
+  template <typename TField_Type>
+  bool operator()(const char *desc_fmt,
+                  String8_Node *(*display_val)(Arena *, String8_Node *, const char *, TField_Type) = hover_display_val<TField_Type>
+                ) const
+  {
+    u64 field_len = sizeof(TField_Type);
+    if (roff < cur_field_off + field_len) {
+      info.rng = { start + cur_field_off, field_len };
+      TField_Type val;
+      memcpy(&val, data + info.rng.start, info.rng.len);
+      display_val(arena, info.desc, desc_fmt, val);
+      return true;
+    }
+    cur_field_off += field_len;
+    return false;
+  }
+};
+
 // `off` is the absolute offset into `data`.
 internal
 Sec_Hover_Info get_section_hover_info(Arena *arena, Section section, u64 off, const u8 *data)
 {
   Sec_Hover_Info info {};
 
-  printf("off: 0x%lX, sec start: 0x%lX\n", off, section.range.start);
+  // printf("off: 0x%lX, sec start: 0x%lX\n", off, section.range.start);
   // assert(off >= section.range.start);
   if (off < section.range.start) {
     printf("WRONG\n"); // TODO: fix TKey Header case
   }
   
+  info.desc = push_str8_node(arena, nullptr, section_names[section.id].c());
+
   u64 start = section.range.start;
   u64 roff = off - start; // offset relative to `section`
+  u64 cur_field_off = 0;
+  Try_Sec_Hover_Fn try_sec_hover { start, roff, data, arena, info, cur_field_off };
   
-  if (section.id == Sec_RNTuple_Anchor) {
-    info.desc = push_str8_node(arena, nullptr, "RNTuple Anchor");
-    // TODO: dry
-    if (roff < sizeof(u32)) {
-      info.rng = { start, sizeof(u32) };
-      u32 val;
-      memcpy(&val, data + info.rng.start, info.rng.len);
-      val = bswap_32(val);
-      val -= 0x40000000;
-      push_str8_node(arena, info.desc, "Object len: %u", val);
-    } else if (roff < sizeof(u32) + sizeof(u16)) {
-      info.rng = { start + sizeof(u32), sizeof(u16) };
-      u32 val;
-      memcpy(&val, data + info.rng.start, info.rng.len);
-      val = bswap_16(val);
-      push_str8_node(arena, info.desc, "Class version: %u", val);
-    } else if (roff < sizeof(u32) + sizeof(u16) + sizeof(u16)) {
-      info.rng = { start + sizeof(u32) + sizeof(u16), sizeof(u16) };
-      u16 val;
-      memcpy(&val, data + info.rng.start, info.rng.len);
-      val = bswap_16(val);
-      push_str8_node(arena, info.desc, "Version Epoch: %u", val);
-    } else if (roff < sizeof(u32) + sizeof(u16) + sizeof(u16) + sizeof(u16)) {
-      info.rng = { start + sizeof(u32) + sizeof(u16) + sizeof(u16), sizeof(u16) };
-      u16 val;
-      memcpy(&val, data + info.rng.start, info.rng.len);
-      val = bswap_16(val);
-      push_str8_node(arena, info.desc, "Version Major: %u", val);
+  switch (section.id) {
+  case Sec_RNTuple_Anchor: {
+    try_sec_hover.operator()<u32>("Object len: %u", [] (Arena *arena, String8_Node *prev, const char *fmt, u32 x) { 
+      x = bswap_32(x);
+      x -= 0x4000'0000;
+      return push_str8_node(arena, prev, fmt, x);
+    })
+    || try_sec_hover.operator()<u16>("Class version: %u")
+    || try_sec_hover.operator()<u16>("Version Epoch: %u")
+    || try_sec_hover.operator()<u16>("Version Major: %u")
+    || try_sec_hover.operator()<u16>("Version Minor: %u")
+    || try_sec_hover.operator()<u16>("Version Patch: %u")
+    || try_sec_hover.operator()<u64>("Seek Header: %u")
+    || try_sec_hover.operator()<u64>("NBytes Header: %u")
+    || try_sec_hover.operator()<u64>("Len Header: %u")
+    || try_sec_hover.operator()<u64>("Seek Footer: %u")
+    || try_sec_hover.operator()<u64>("NBytes Footer: %u")
+    || try_sec_hover.operator()<u64>("Len Footer: %u")
+    || try_sec_hover.operator()<u64>("Max Key Size: %u")
+    ;   
+  } break;
+  
+  case Sec_TFile_Header: {
+    u32 root_version_be;
+    memcpy(&root_version_be, data + start + 4, sizeof(u32));
+    u32 root_version = bswap_32(root_version_be);
+    b32x is_big = root_version > 1000000;
+
+    if (is_big) {
+      try_sec_hover.operator()<u32>("ROOT magic number")
+      || try_sec_hover.operator()<u32>("ROOT version: %u", [] (Arena *arena, String8_Node *prev, const char *fmt, u32 x) {
+        x = bswap_32(x);
+        x -= 1000000;
+        return push_str8_node(arena, prev, fmt, x);
+      })
+      || try_sec_hover.operator()<u32>("fBEGIN: 0x%lX")
+      || try_sec_hover.operator()<u64>("fEND: 0x%lX")
+      || try_sec_hover.operator()<u64>("Seek Free: 0x%lX")
+      || try_sec_hover.operator()<u32>("NBytes Free: %u")
+      || try_sec_hover.operator()<u32>("N Free: %u")
+      || try_sec_hover.operator()<u32>("NBytes Name: %u")
+      || try_sec_hover.operator()<u8>("Units: %u")
+      || try_sec_hover.operator()<u32>("Compression: %u")
+      || try_sec_hover.operator()<u64>("Seek Info: 0x%lX")
+      || try_sec_hover.operator()<u32>("NBytes Info: %u")
+      ;
+    } else {
+      try_sec_hover.operator()<u32>("ROOT magic number")
+      || try_sec_hover.operator()<u32>("ROOT version: %u")
+      || try_sec_hover.operator()<u32>("fBEGIN: 0x%lX")
+      || try_sec_hover.operator()<u32>("fEND: 0x%lX")
+      || try_sec_hover.operator()<u32>("Seek Free: 0x%lX")
+      || try_sec_hover.operator()<u32>("NBytes Free: %u")
+      || try_sec_hover.operator()<u32>("N Free: %u")
+      || try_sec_hover.operator()<u32>("NBytes Name: %u")
+      || try_sec_hover.operator()<u8>("Units: %u")
+      || try_sec_hover.operator()<u32>("Compression: %u")
+      || try_sec_hover.operator()<u32>("Seek Info: 0x%lX")
+      || try_sec_hover.operator()<u32>("NBytes Info: %u")
+      ;
     }
+  } break;
+  
+  case Sec_TFile_Object: {
+    // FIXME
+    try_sec_hover.operator()<u32>("ROOT magic number")
+    || try_sec_hover.operator()<u16>("Class version: %u", [] (Arena *arena, String8_Node *prev, const char *fmt, u16 x) { 
+       x = bswap_16(x);
+       x -= (x > 1000) * 1000; 
+       return push_str8_node(arena, prev, fmt, x);
+    })
+    || try_sec_hover.operator()<u32>("Created: ", hover_display_datetime_str)
+    || try_sec_hover.operator()<u32>("Modified: ", hover_display_datetime_str)
+    || try_sec_hover.operator()<u32>("NBytes Keys %u") 
+    || try_sec_hover.operator()<u32>("NBytes Name %u") 
+    ;
+  } break;
+
+  default:;
   }
- 
+
+   
   return info;
 }
diff --git a/src/root/RMicroFileReader.cxx b/src/root/RMicroFileReader.cxx
index 829877d..d23d143 100644
--- a/src/root/RMicroFileReader.cxx
+++ b/src/root/RMicroFileReader.cxx
@@ -1072,7 +1072,10 @@ Root_File_Info get_root_file_info(const char *fname, bool is_big_file)
 {
    RTFString fileName { fname };
    Root_File_Info fileInfo {};
-   fileInfo.tfile_header_nbytes = RTFHeader{}.GetSize();
+   RTFHeader header;
+   if (is_big_file)
+      header.SetBigFile();
+   fileInfo.tfile_header_nbytes = header.GetSize();
    fileInfo.tfile_obj_seek = 100; // kBEGIN
    fileInfo.tfile_obj_nbytes = sizeof(RTFFile) + fileName.GetSize() + RTFString{}.GetSize() + RTFUUID{}.GetSize();
    fileInfo.version_seek = offsetof(RTFHeader, fVersion);