Wanting to tap the rgb port

[old_tv_nut]

Teletext use was expected to mainly be on-screen, with printing used infrequently, much like a modern internet service. In Chicago, where Zenith was located, the service from Atlanta was broadcast. For a while, there was a long-haul trucking jobs listing service, and it was intended that teletext receivers would be installed at major truck stops so independent truckers could bid/apply for runs (I'm not sure exactly how it worked). Another service was intended for home use and had things like news summaries, horoscopes, recipe of the day, and so on. I had a Zenith rear projo with Teletext at home, and would call the service sometimes to request a particular recipe to be posted, or answer the day's puzzle. The broadcasts in Chicago also contained test pages of repeating characters that made the clock recovery particularly difficult. One of these was titled something like "Page for Gary." Gary was an engineer at Zenith working on Teletext. The page stayed up long after the attempts at commercial service died, until Teletext was removed entirely.

PS: Teletext coding was at a low data rate, intended to be relatively ghost-resistant without requiring a ghost correction circuit in the receiver.