# Mnemonics

'F+' & 'F-' | Control Background Filling

GUI Display

## Description

The 'F+' and 'F-' mnemonics are used to control the automatic background filling of fonted text and the text region portions of Check Boxes and Radio Buttons.

When the filling is disabled by issuing a PRINT 'F-', the background region for the text will not be erased before outputting the text. If the colour of the background region does not match that of the screen, the erase will still be performed.

The primary use of these mnemonics is to allow for the generation and output of background images on screen.

The default setting is 'F+' (background region is erased to background colour).