The present paper describes the computer aspects of a reaction time experiment with couples. The hardware consists of two computers connected through a local area network. Issues that deal with the first PC include timing routines, screen control, mice data decoding, and synchronization of computer software—written in Assembler for a PC without hard disk—with information presented in a videotape. The second computer was used for data processing that was written in VBA. Although the system was created for a dedicated purpose, it is easily applicable to other environments.