’这是一个查看光标坐标的程序。
’用上下左右键移动光标，可以看到它的坐标。
’按Esc键退出程序
SCREEN 0, 1
LET y = 1
LET x = 1
DO
  LOCATE x, y, 1
  DO                         '屏幕等待
    LET k$ = INKEY$
  LOOP UNTIL k$ <> ""
  CLS
  SELECT CASE k$
    CASE CHR$(27)                 'Esc键退出程序
      END
    CASE CHR$(0) + CHR$(80)       '下移光标
      LET x = x + 1
      IF x > 25 THEN LET x = 25
    CASE CHR$(0) + CHR$(72)       '上移光标
      LET x = x - 1
      IF x < 1 THEN LET x = 1
    CASE CHR$(0) + CHR$(75)       '左移光标
      LET y = y - 1
      IF y < 1 THEN LET y = 1
    CASE CHR$(0) + CHR$(77)       '右移光标
      LET y = y + 1
      IF y > 80 THEN LET y = 80
  END SELECT
  LOCATE x, y, 1
  LET a = CSRLIN
  LET b = POS(n)
  COLOR 12
  PRINT USING "###"; a;           '显示光标的坐标
  COLOR 14
  PRINT USING "##"; b
LOOP