Radio Shack TRS-80 Operation Manual page 86

Operation Manual
Computer Graphics
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SCREEN
Selects Screen
SCREEN lets you select the proper screen.
Example
CALL SCREEN(~)
Sample Program
This example turns off the graphics display, draws a circle,
then turns on the graphics display. The circle is then
visible.
EXAMPLE FOR SCREEN
LOGICAL CMD
CMD=l
CALL
GRPINI(~)
CALL CLS
CALL SCREEN (CMD)
CALL
SETXY(3~~,l2~)
CALL
CIRCLE(l~~,l,~.~,~.~,~.~)
CALL PAINT(l,l)
DO
2~ I=l,l~~~~
CONTINUE
CMD=~
CALL SCREEN (CMD)
END
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