Abstract: A video game cartridge that can be plugged into a video game machine to enable a user to request and play a video game for a predetermined number of video frames. The cartridge has a receiver for receiving the video game program and the predetermined frame count in response to a request from the user. The program and frame count is then stored in a memory of the cartridge. Finally, the cartridge has a counter which changes its value when the user is actively playing the video game program. The counter ceases to change its value when the user is not playing the video game program. When the counter reaches a predetermined limit, the user is no longer authorized to play the video game program.

Abstract: A self-contained CD-ROM player which can be installed and used as simply as a VCR. The CD-ROM player includes a CD-ROM drive and supporting hardware and software to activate and execute a program on a CD-ROM disk. It is not necessary to explicitly issue commands to activate and use the disk. The user interface is completely intuitive and simple even for someone who is completely computer illiterate. This player allows everyone, both proficient computer users and those not so proficient, to use the vast library of CD-ROM programs that have been written for personal computers.

Abstract: This optical sensor has cylindrical symmetry and is comprised of a semiconductor light source/light detector combination and an optical element comprising a single lens, where the sensor is particularly suitable for uses in accurate position detection in data recording systems. In a preferred embodiment, the light source is a forward-biased p-n junction, while the light detector is a reverse-biased p-n junction located below the light source and coaxial therewith. Light from the source is directed to a point on a data recording medium and the light reflected therefrom passes through the light source to the light detecting junction. The ac signal corresponding to the reflected light is an indication of the position of the recording head with respect to the data storage medium.