You got your datastream in my sitcom! (encoded information in TV signals)

Factual Questions
1

I recently got an RCA TV with the “Guide Plus” feature. When the set is turned off at night, it downloads TV listings, news headlines, and (of course) advertisements through the airwaves.

Then I got a VCR which claims to set its clock automatically by reading the time off the air (though it doesn’t seem to work), and on a few channels, the network name appears on the screen when I press ‘display’. My friend’s VCR does the same thing, but also shows the name of the program.

[ol]
[li]These features are pretty cool, so why haven’t I heard of them before? I didn’t know the network and program names were even part of the signal, and the ability to show them wasn’t mentioned anywhere in my VCR’s packaging or instructions.[/li][li]Why aren’t they supported by more equipment? My VCR doesn’t show program names or listings, and my friend’s nearly brand-new TV doesn’t show the network, program, or listings.[/li][li]Why aren’t they supported by more channels? Only the local CBS and FOX station (and about 1/3 of the cable channels) display network names at all, and CBS shows up as “NET6”.[/li][li]Are these services related to the extra closed-caption modes? Some sets can show 4 channels of captions and full-screen text, which I’ve never actually seen used. I used teletext in Europe, and our text mode doesn’t seem to have the potential for anything like that.[/li][li]Is there any other information being sent over the air like this?[/li][/ol]

2

These features are pretty cool, so why haven’t I heard of them before?

It’s called EDS or Extended Data Services. It’s not heavily promoted, because the services they provide are really minimal. EDS is not intended to be a teletext service, but rather certain forms of utilitarian data such as V-chip program rating codes, time signals (on PBS mainly), network names, and so on.

Why aren’t they supported by more equipment?

With digital television in the US, there’s no point in adding lots of new features to new analog sets. If you knew that someone was going to tear down your house in five years, would you still have your kitchen remodeled?

Why aren’t they supported by more channels? Only the local CBS and FOX station (and about 1/3 of the cable channels) display network names at all, and CBS shows up as “NET6”.**

NET6 is an internal network code used by CBS

Are these services related to the extra closed-caption modes?

Not really. It’s the same technology, though.

Is there any other information being sent over the air like this?

Not that I know of, although I wouldn’t rule out the prospect of easter eggs hiding in the unused closed caption streams or the text pages. The US actually has a teletext standard, and there was a working system in the 1980s; there could be a couple of pages still floating around, again easter eggs for intrepid explorers.