The grub legacy (grub 0.97) supported LBA access, but since it was processing in 32-bit, it could only access up to 2 TiB.
By applying patches of the reference site below, it became accessible with 48-bit LBA and supported disks over 2 TiB. However, it didn't support the 64bit feature of ext4, so it couldn't access the recently created ext4 filesystem.