Separated Block Sextant-1245

It is a six-part tile for simple graphics made from text. Teletext, a TV service developed in the UK in the early 1970s, sent pages of text and simple graphics to television sets. Each tile split a character cell into two columns and three rows; arranging tiles let broadcasters draw maps, charts, and headings on screens built around text. Here, “sextant” names the six sections of the cell.

The digits in “1245” identify the four filled positions. Teletext’s separated mode left a narrow gap between mosaic blocks. Giving joined and separated patterns distinct characters let emulators reproduce older teletext pages and software that already used both styles.