Sample program JS cls(); var x=15; while(scr(x,5)==0){ lc(x,5); log("O"); lc(rnd(32),23); log("*"); scroll(0); sleep(50); var k=inkey(); x=x-(k==28)+(k==29); } reference LPC1114 [en] [jp] / GD32VF103 [en] [jp] FORTH cls 15 BEGIN DUP 5 lc 0 . 32 rnd 23 lc 1 . 0 scroll DUP 5 scr 0 = WHILE 30 sleep inkey DUP 28 = IF SWAP 1 - SWAP THEN DUP 29 = IF SWAP 1 + SWAP THEN DROP REPEAT reference LPC1114 [en]