Ceefax broadcast its pages in a cycle: you keyed a number and the page arrived when the cycle reached it, not before. This page re-runs that contract with this site's own pages. The cycle below is a script; nothing is transmitted; the wait is real.
Ceefax was the world's first teletext information service. The BBC started it in 1974; it ended at 23:32:19 BST on 23 October 2012, after 38 years on air. The format showed 24 rows of 40 characters, and the broadcaster sent every page in a continuous cycle, so the more pages a magazine held, the longer each one took to arrive. A page keyed by the viewer appeared when the cycle brought it, not before.
This page runs that contract as a script. The six pages are this site's own, filed as broadcast pages: the index, the field notes, the experiments, a clock, the story of the last night, and these instructions. Nothing is transmitted. The cycle is real software, so the page will not show itself before its turn. A receiver with page memory, like the ones that stored the magazine as it went past, can show any page instantly: open /teletext?page=104.
Wikipedia, "Ceefax"; Wikipedia, "Teletext". Facts checked against those pages on 4 August 2026.