Holotape

A holotape, also called a holodisk or holo-disc, is a laser-readable storage device produced by Wattz Electronics. It is based on Tape Holography Technology and stores information safely for extended periods of time.

Background
Developed using tape holography technology as early as 2063, holotapes are a high-density, laser-readable, manufactured-crystal storage device. These disks and tapes were the very latest in pre-War information storage technology and quickly became the most widespread data storage medium, available in a variety of compatible variants.

While early holotape models could store only as much as 256 kilobytes of data, averaging between 128 and 64 kilobytes, the latest models from 2077 could store up to 4 terabytes (4,000 gigabytes) of data. Storage in holotapes were divided into "blocks" with a capacity of 256 blocks to store data. The amount of data in a holotape all depended on the compression of the data.

In 2287, the Institute had holotapes of their own, capable of storing the entirety of libraries, such as the Boston Public Library, onto their storage banks. Holotapes were capable of storing transmissions and software backups, and G.E.C.K.'s were advertised as including a holotape with an abridged version of the Library of Congress as standard. Holo Generators were used to create THT entertainment tape players, but some did not function after the war.

Holotapes had more uses before the war aside from data storage. Specific models were meant to hold entertainment, such as music, movies, and holotape games, with special-purpose players developed for displaying large, high resolution volumetric images or to play holotapes for personal use in a home environment via holotape players. Holotapes could be played on terminals, their content including movies, video games and music. 

A RobCo terminal with a holotape player was added as a part of the time capsule known as the "Treasures of Jamaica Plain," displayed among other remnants of the past in the Jamaica Plain Town Hall basement.

Gameplay
Their appearance varies between games. In Fallout, Fallout 2, and Fallout Tactics, holotapes are interchangeably referred to as holodisks. In Fallout 3 and New Vegas, they are gray and in Fallout 4 and Fallout 76, holotapes are orange. When played, it can be seen inserted into the Pip-Boy.