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,
S-VHS can be recorded along with the normal video signal. As a result, this teletext data is also able to be decoded and displayed on-screen as an overlay of the conventional TV picture (though not on standard VHS machines). A suitably teletext-equipped receiver/decoder (TV, PC card, etc.) displays the recorded teletext data information as if the video were being viewed as a real-time live broadcast. S-VHS video cassette recorders (VCRs) and cassette tapes are nearly identical in appearance and operation, and backward compatible with VHS. Older VHS VCRs cannot play back S-VHS recordings at all, but can record onto an S-VHS