Abstract: An information display device adapted to be mounted on the safety bar of a ski-lift chair. The device has a tubular base which is rigidly attached to the safety bar. A tubular carrier is rotatabley secured to the tubular base. This tubular carrier provides a cylindrical support surface for information to be displayed. A tubular cover is mounted about the carrier and fixed to the tubular base to protect the tubular carrier and the information attached to it.

Abstract: A user-removable optical data storage system is provided. A rotatable first-surface medium is enveloped in a cartridge. The cartridge provides relatively large data capacity such as about 0.25 Gbytes or more despite a relatively small size such as about 35 mm×35 mm×3 mm. Preferably the cartridge substantially seals the data surfaces of the medium when the cartridge is withdrawn from a drive and at least a portion of one surface is automatically exposed to the objective of an optics arm when said cartridge is inserted in the drive. Tracking involves rotating an optic arm about an axis parallel to the disk rotation axis. Focus can involve pivoting the arm about an axis parallel to the disk surface.