No tips - except at a guess 10 or 20% can't and won't ever see them. I spent ages trying to make these things work in the 80s or 90s whenever the posters were

No tips - except at a guess 10 or 20% can't and won't ever see them. I spent ages trying to make these things work in the 80s or 90s whenever the posters were the craze. Never got close, and there were quite a few others they simply didn't work on.