BBC BASIC Programmers' Reference

Inverse video is a display mode where text and graphics on a display are presented as a negative of their original appearance.

by Jon Ripley, May 2006

To read the current foreground and background text colours use the following code:

        fgcol% = @vdu%?70
        bgcol% = @vdu%?71

Here fgcol% and bgcol% are normalised values in the range 0 to 15 representing the logical colour used.

To invert the colours of the text display use the following code:

        COLOUR bgcol%
        COLOUR 128+fgcol%

Now any text you PRINT will be in inverse video.

To restore the original foreground and background text colours use the following code:

        COLOUR fgcol%
        COLOUR 128+bgcol%

by Richard Russell, May 2006

You can invert all the existing colours in the output window (or in the graphics viewport, if one is defined) as follows:

        GCOL 4,128
        CLG

This will affect both text and graphics. Executing this code twice will restore the original colours.