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.

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.

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.

• bedstead-001.001.zip – Full source and binary distribution containing everything below.
• bedstead.c – The C program that generates the font.
• bedstead.sfd – The Spline Font Database file for use with Fontforge.
• bedstead.otf – The finished font in OpenType format.
• bedstead-ext.sfd, bedstead-ext.otf – Spline Font Database and OpenType versions of the extended font.
• bedstead-10.bdf, bedstead-20.bdf – Bitmap versions at 10 and 20 pixels high.
• bedstead-10-df.png, bedstead-20-df.png – 10-pixel and 20-pixel tilesets for use with Dwarf Fortress.

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

bzr branch http://bjh21.me.uk/bedstead/