One of the strengths of the Amiga - at the time - was that it generates a "native" PAL/NTSC video signal, compatible with that of any home TV, making it naturally suited for video and broadcasting production. 

Genlocking - the inter-locking of two video signals, allowing blending, chroma-keying, overlaying, etc. - was the latest thing, and the Amiga could provide such a video signal without any expansion devices.

Probably completely unknown in Europe, a US company created a TV channel out of this combination. It lauched in 1981 as "Electronic Program Guide" using Atari 8-bit computers for image generation. Until about 1998, moving to several Amiga setups and undergoing several name changes including "Prevue" and "Prevue Guide", it provided TV program information, weather forecast, celebrity interviews, etc. In it's final Amiga version the software called "PrevueGrid" was able to display video feeds on a split screen, and play back audio feeds at the same time. After 1998 the company continued under a different name, and the Amiga platform was gradually replaced with PCs. 

https://en.wikipedia.org/wiki/File:PrevueChannel.png

So what you saw on your TV on this channel at the time was provided by an Amiga computer (together with video feed, genlocking, and other broadcasting devices). Fast-forward to the present day, YouTube, and a worldwide community supplying video content. A seemingly endless amount of original material, digitized footage, and captured broadcast video are freely available on the internet - including hours of recorded Prevue air time. Which is great, both for Amiga enthusiasts, and TV viewers that enjoy the nostalgia. 

But the fun part comes with the mishaps. Of course something goes wrong every once in a while, and AmigaOS running PrevueGrid is no exception. As is the person operating the Amiga computer in question. This results in an enjoyable mix of low-res video, genlocking gone wrong, Amiga and PrevueGrid system reboots, and other little glitches, together with oldskool TV programming - a nice look back at 1990s broadcasting technology and content.

Here are a couple of video links to get you started:

The Saddest Prevue Guide That Ever Lived 
https://www.youtube.com/watch?v=rLoEMcIPdbI

Prevue Guide Guru Meditation 10/9/91
https://www.youtube.com/watch?v=jC6MKcmETWE

Prevue Guide failure (with reboot) May 31, 1991 (part 1 of 4)
https://www.youtube.com/watch?v=Ybx1HDMw6wk

PREVUE Guide / Channel rebooting - Commodore Amiga Guru Meditation visible
https://www.youtube.com/watch?v=4x9Vado0S7M

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Additional sources:

http://prevueguide.com

http://prevueguide.com/wiki/Prevue_Grid (software)

http://prevueguide.com/ULVSG/Index.html

https://en.wikipedia.org/wiki/History_of_Pop_(American_TV_channel)