BBC Micro depth, resolution and memory economy. In the first models, the OS and applications were left with the RAM left over from the display mode. Mode 7 was a Teletext mode, extremely economical on memory and an original requirement due to the BBC's own use of broadcast teletext (Ceefax). It also made the computer useful as a Prestel terminal. The teletext characters were generated on board, for use with monitors and TV sets without a Teletext receiver. Train time displays at UK stations were driven by BBC Master computers in this mode until around the late 1990s. Mode 7 used only
Teletext systems as the "Broadcast Teletext Specification". With some tweaks to allow for alternative national character sets, and adaptations to the NTSC 525-line system as necessary, this was then promoted internationally as "World System Teletext". It was accepted by CCIR in 1986 as "CCIR Teletext System B", one of four recognised standards for teletext worldwide. In France, where the SECAM standard is used in television broadcasting, a teletext system was developed in the late 1970s under the name "Antiope". It had a higher data rate and was capable of dynamic page sizes, allowing more sophisticated graphics. It was phased out in favour