Bedstead is an outline font based on the characters produced by the Mullard SAA5050 series of Teletext Character Generators. The SAA5050 is familiar to those of a certain age as the chip that produced the MODE 7 display on the BBC Microcomputer. It generates characters from a 5 × 9 pixel matrix, smoothing diagonal lines to produce an interlaced 10 × 18 matrix for each character. Bedstead extends that algorithm to continuity, converting a 5 × 9 pixel grid into an outline with smooth diagonals.

Bedstead includes all the character designs from the SAA5050 and its various sister chips, including Cyrillic and Hebrew alphabets. It also has a large number of custom-designed glyphs, all of them of course based on the same 5 × 9 pixel grid.

[ A sample of Bedstead's characters ]

The standard version of Bedstead is based on a square pixel grid. This is good for displays with square pixels, but not entirely faithful to the SAA5050. There is a second version, Bedstead Extended, that more accurately reflects the character shapes generated by an SAA5050 driving a 576i display.

[ Bedstead and Bedstead Extended ]

The outline version of Bedstead is generated by an ANSI C program which emits a Spline Font Database file for use with Fontforge, which can convert it into most reasonable font formats.

The code to generate Bedstead is held in Bazaar. You can get your own copy by running

bzr branch