Radio Shack TRS-80 Operation Manual page 55

Computer Graphics Operation Manual
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automatically set to the Text Screen. If the program is
still running after executing the statement, BASICG will
revert to the screen that was in effect prior to executing
the statement.
Examples
1.0' SCREEN 1
2.0' LINE (15.0',15.0')-(2.0'.0',2.0'.0')
The computer executes the short program but the Graphics
Screen cannot display the graphics because of the SCREEN 1
command. To display the line, type: SCREEN.0' <ENTER>.
1.0' CLR
2.0' SCREEN 1
3.0' LINE(1.0',1.0')-(255,191)
4.0' LINE(~,191)-(255,~)
5.0' A$=INKEY$: IF A$=""THEN 5.0'
6.0' SCREEN .0'
7.0' A$=INKEY$: IF A$=""THEN 7.0'
8.0' GOTO 1.0'
The computer executes the program (draws two intersecting
lines) but the screen cannot display the graphics because of
SCREEN 1. By pressing any key, the graphics are displayed
because of SCREEN .0'.
1.0' CIRCLE
(2.0'.0',1.0'~),1.0'.0'
2.0' PAINT
(2.0'.0',1.0'~),"44",1
Now run the program and type:
SCREEN .0' <ENTER>
This command turns the Graphics Screen ON.•
By entering the SCREEN 1 and SCREEN .0' commands, you can
alternately turn the Graphics Screen OFF and ON without
losing the executed program display.
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