Teletext Text
The Teletext screen is 40 characters across by 25 down, drawn from the 6×10 SAA5050 character set. Colour is serial: a control cell sets the ink for the rest of the row, until another control cell overrides it.
The screen
A page is 40×25 cells of 6×10 pixels. Each cell holds one code. A code below 32 is a control that sets the colour, the graphics mode or an effect that follows on the row.
| Detail | Value |
|---|---|
| Screen | 40 × 25 characters |
| Cell | 6 × 10 pixels |
| Attribute model | Inline, serial |
Attributes
Colour is set by a serial control. A control cell sets the text colour, and it holds from that cell along the row until another control changes it. The control takes a whole cell, shown as a space. To read a cell's colour, look left along the row for the nearest control, and use the default when the row holds none. Teletext also carries mosaic graphics, double height and flash as controls; those are special attributes, kept for a later pass.
Colours
Teletext shows eight colours, the palette Sprites.Platform.Teletext.Palette. A colour control names the text colour; the ground is black unless a new-background control holds the last colour. The default is white on black.
In the editor
The Teletext editor opens a 40×25 page on white ink and black paper, using the colour attributes. The details come from Sprites.Platform.Teletext.Text: DefaultWidth 40, DefaultHeight 25, WholeCell true. The mosaic graphics, double height and flash controls are special attributes, so the editor lays colour text without them for now. See the text media page and Text storage.