字处理演示程序 实现书上程序已经有的字处理功能，即左移，右移和插入的功能 扩展该字处理程序的功能，使其拥有上移，下移和删除的功能 -word processing demonstration program written procedures have been some word processing function, which is to the left. the shift to right and insert the word processing function

按下K1时，P0口LED上移一位； 按下K2时，P0口LED下移一位； 按下K3时，P2口LED上移一位；按下K4时，P2口LED下移一位 -The P2 port LED Down a press K1 P0 port LED shift one K2, Press, P0 port LED Down A Press K3, P2 port LED shift one press K4 position