说明：  ps2键盘的命令集，编写键盘驱动时有用。EDH:置位/复位 LED 指示器。键盘右上角有三个 LED 指示器,分别反映 Caps、Num 和 Scroll 三个键的 锁定情况。参数字节如表 2 所列。
(ps2 keyboard command set, the preparation of useful keyboard-driven. EDH: Set/reset LED indicator. The upper right corner of the keyboard has three LED indicators, respectively, reflecting the Caps, Num and Scroll Lock keys in three cases. Parameter bytes as listed in Table 2.)