Teletext default graphics mode (mode 7) was based on Teletext display, and the computer could be used to create and serve Teletext-style pages over a modem connection. With a suitable adapter, the computer could receive and display teletext pages, as well as software over the BBC's Ceefax service, for a time. The Philips P2000 home computer's video logic was also based on a chip designed to provide teletext services in TVs. Prestel was a British information-retrieval system based on teletext protocols. However, it was essentially a different system, using a modem and the phone system to transmit and receive the data,
Teletext in the USA. A few other services were offered by some large-market TV stations in the US throughout the 1980s, such as Metrotext from KTTV in Los Angeles and KeyFax from WFLD in Chicago. Despite this, the system never caught on in the USA partly due to EIA-608 being deployed for captioning before Teletext was introduced and the higher cost of Teletext receivers. In the 1980s a similar system called Telidon was developed in Canada by the Department of Communications. It used a simple graphics language that would allow a more complex circuit in the TV to decode not only