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 of decoder circuitry is sometimes marked on televisions as CCT (Computer-Controlled Teletext), or ECCT (Enhanced Computer-Controlled Teletext). Besides the hardware implementations, it's also possible to decode teletext using a PC and video capture or DVB board. Adoption in the United States was hampered due to a lack of a single teletext standard and consumer resistance to the high initial price of teletext decoders. Throughout the period of analog broadcasting, teletext or other similar technologies in the US were practically non-existent, with the only technologies resembling such existing in the country being closed captioning, TV Guide On Screen, and Extended Data