There are 5 unique codex entries in the Achievement: Datacrons section on Hoth. They are accessible to all players regardless of class or faction.
Galactic History 63: The Terentatek Hunt is obtained from interacting with the +4 Orange Mastery datacron.
Codex type: Achievement: Datacrons | Faction: Both | Class: All
Associated Achievement: Hoth Datacron Master
Galactic History 64: The Kanz Disorders is obtained from interacting with the +4 Green Endurance datacron.
Codex type: Achievement: Datacrons | Faction: Both | Class: All
Associated Achievement: Hoth Datacron Master
Galactic History 65: An Exile on Rhen Var is obtained from interacting with the +4 Yellow Presence datacron.
Codex type: Achievement: Datacrons | Faction: Both | Class: All
Associated Achievement: Hoth Datacron Master
Hydro-thinner is purchased from Gthykas an Imperial character or Brinton as a Republic character for 18,000 credits and is required to access the codex.
Galactic History 66: The Jedi Covenant is obtained from interacting with the Red Matrix Shard datacron.
Codex type: Achievement: Datacrons | Faction: Both | Class: All
Associated Achievement: Hoth Datacron Master
Depleted Datacron is looted from Ancient Probe and is required to access the codex. Ancient Probe wanders around the Southern Snowdrift Hills and Northern Snowdrift Hills map sections.
Galactic History 67: Mandalore the Ultimate is obtained from interacting with the +4 Red Mastery datacron.
Codex type: Achievement: Datacrons | Faction: Both | Class: All
Associated Achievement: Hoth Datacron Master