128 28 Teletext control codes and MODE 7 MODE 7 is a Teletext compatible display mode which is very economical in its use of memory. It can provide a full colour text display with limited, but full colour, graphics. This mode is strongly recommended for applications which do not require very fine graphic detail. MODE 7 uses the standard Teletext control codes to change colours rather than the BBC BASIC COLOUR and DRAW statements. It cannot be overemphasied that MODE 7 requires different codes and statements from those available in MODES 0 to 6 . The MODE 7 display consists of 20 lines of 40 characters. Each line will normally consist of white letters and numbers (text) on a black background.
If the user wishes to change the colour of the text or the background then a control code must be sent to the screen with a PRINT or VDU statement. By way of explanation let’s examine one typical line of characters on a MODE 7 screen. The screen display consists of 25 lines (numbered 0 to 24) each containing up to 40 characters (0 to 39). Let’s examine a typical line and see what is displayed on the screen.