Teletext is one way. Your receiver decodes the page you request, but you have no uplink.
Teletext was made by major broadcasters, so NBC/ABC/CBS in the US might have had a service. It is just broadcasted as part of the signal, so the actual hardware is in the end users device. All TV's in the UK and Europe just had teletext decoders built in as standard. The cost of entry was not high at all. The only expense was updating the content. But honestly, that wasn't really a massive effort unless you wanted a lot of graphics (ASCII style, obviously.) It was a bout as much effort as a local news paper or a well maintained BBS.
Teletext was made by major broadcasters, so NBC/ABC/CBS in the US might have had a service. It is just broadcasted as part of the signal, so the actual hardware is in the end users device. All TV's in the UK and Europe just had teletext decoders built in as standard. The cost of entry was not high at all. The only expense was updating the content. But honestly, that wasn't really a massive effort unless you wanted a lot of graphics (ASCII style, obviously.) It was a bout as much effort as a local news paper or a well maintained BBS.