A verism tape, or history tape, was a data storage medium utilized on the planet Sarpeidon prior to the supernova of Beta Niobe in 2269. Several thousand of these round discs were stored in their library. They could be accessed via tape viewer.
That year, under the mistaken impression that they were native to the planet, Mr. Atoz offered James T. Kirk, Leonard McCoy, and Spock the opportunity to look through the various verism tapes in order to choose the era of history they wished to escape to. (TOS: "All Our Yesterdays")