Narrow band TV

We have a very diverse hobby and there is only so much we can enjoy. One of my interests, although I have never tried it, is narrow band TV. This is how the first TV was sent with 30 lines on ordinary radio channels. These days there are digital scan converters to make NBTV from wideband signals. There certainly used to be a net on 80m where NBTV was sent. I suspect there are systems and software that allows NBTV to be watched on a PC.