bioskey: keyboard interface
int bioskey(int cmd);
Prototype in bios.h
cmd Action
0 Return key scancode from buffer and delete it from the buffer. Wait for the next key if the buffer is empty.
1 Return key scancode from buffer, but do not delete it from the buffer. Return 0 if the buffer is empty.
2 Return the BIOS shift state flags.
透過引數0、1、2完成三種功能，0讀取一個按鍵，並從緩衝區取出，1從緩衝區讀取一個按鍵，並且保留在緩衝區（下次可以讀取），2獲取SHIFT等鍵的狀態。注意讀出的不單是ASCII碼，還包括掃描碼。
bioskey: keyboard interface
int bioskey(int cmd);
Prototype in bios.h
cmd Action
0 Return key scancode from buffer and delete it from the buffer. Wait for the next key if the buffer is empty.
1 Return key scancode from buffer, but do not delete it from the buffer. Return 0 if the buffer is empty.
2 Return the BIOS shift state flags.
透過引數0、1、2完成三種功能，0讀取一個按鍵，並從緩衝區取出，1從緩衝區讀取一個按鍵，並且保留在緩衝區（下次可以讀取），2獲取SHIFT等鍵的狀態。注意讀出的不單是ASCII碼，還包括掃描碼。