 
 <prompt> Wetin dem dey call recording of moving visual images for tape or digital? <response>: Na for di 1980s e be like say digital telephony transmission networks start dey possible, like wit ISDN networks wey dey assure minimum bit rate (usually 128 kilobits/s) for compressed video and audio transmission. During dis time, dem dey research oda forms of digital video and audio communication. Many of these technologies, like di Media space, no dey too popular like videoconferencing but dem still dey important for research. Di first systems wey dey dedicated start to show for market as ISDN networks dey expand worldwide. One of di first commercial videoconferencing systems wey dem sell to companies na from PictureTel Corp., wey do Initial Public Offering for November, 1984. 