1 READ DX,DY:GRAPHICS 0:DATA 4,4,-4,4,4,-4,-4,-4,0,0
2 FOR Y=0 TO 12:FOR X=0 TO 12-Y
3 POSITION 8+DX+X*SGN(-DX),8+DY+Y*SGN(-DY):PRINT "*"
4 NEXT X:NEXT Y:READ DX,DY:IF DX<>0 THEN GOTO 2