DEFINITION MODULE BBC;

(*
    Title: 	Special GKS functions for BBC terminal 
    LastEdit:	"Tue Feb 26 15:10:04 1985"
    Author: 	jd
		Cambridge University Computer Laboratory
*)

FROM GKSTypes IMPORT WS;

EXPORT QUALIFIED  GRAPHICSMODE, GraphicsMode;

TYPE GRAPHICSMODE = (TwoColour, FourColour, EightColour);

PROCEDURE GraphicsMode (bbc: WS; mode: GRAPHICSMODE);
    (* sets the machine into a mode which allows both text and graphics in the
       specified number of colours. In all modes the background colour is
       white (which appears as blue on the screen to avoid flicker) for
       compatibility with other output devices. The available colours are
            TwoColour:  black and white
            FourColour: black, red, green and white
            EightColour: black, red, green, yellow, blue, magenta, cyan, white
                In this mode, blue appears as white because the background is
                blue!
    *)

END BBC.
