dyer (01/19/83)
The problem is that most video tapes available for rental are "copyguarded". The vertical sync component of the video signal is intentionally weakened. Most, though not all, TV's can still produce an acceptable picture despite this (sync detection having a binary threshold--yes/no). However, when a copy of a copyguarded tape is replayed, because of the inevitable losses during copying, the vertical sync is so weak that most TV's cannot produce a viewable picture. Most video magazines have ads selling devices called "Image Stabilizers", which are designed to hook up between your VCR and TV, and regenerate a full-amplitude vertical sync signal. Officially, these are for use with those few TV's which cannot reproduce copyguarded signals. More often, they are connected between two VCR's to defeat the original's copyguard. Steve Dyer decvax!wivax!dyer sdyer@bbn-unix