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   _bios_keybrd, bioskey

   Usage
   #include <bios.h>
   int _bios_keybrd(int flag);
   int bioskey(int flag);

   Description
   These  names  refer to the same function. The two  spellings  are  for
   compatibility  with other compilers. bioskey passes flag to  the  BIOS
   interrupt 0x16 - the keyboard interrupt. The values for flag are:

   0    Read the next key value from the keyboard input buffer. Wait  for
        one if there are not any available.
   1    Determine if any keys are in the keyboard input buffer.
   2    Read the status of the shift keys.

   Example
   #include <bios.h>
   #include <stdio.h>

   main()
   {
   int key,shift;
   int lastshift = 0;
        while (1)
        {
             shift = bioskey(2); /* If shift status changes */
             if(shift != lastshift)
                  printf("shift = 0x%02x\n",shift);

                                 /* If a key is available */
             if(bioskey(1))
             {
                                 /* Read the key */
                  key = _bios_keybrd(0);
                  if((key & 0xFF) == 'q')
                       break;
                  printf("key = 0x%04x\n",key);
             }
             lastshift = shift;
        }
   }

   Return Value
   If flag is 0, the value returned is the key value. The ASCII value  of
   the  key  is returned in the low byte, and the scan code in  the  high
   byte. If the low byte is 0, then the key value is not an ASCII key (it
   might  be  an arrow or function key). If flag is 1, 0 is  returned  if
   there are no keys in the input buffer, otherwise the next key value is
   returned.  The key value is not removed from the input buffer, and  is
   still  available to be read. If flag is 2, the value returned  is  the
   state   of  the  shift  keys  encoded  into  the  bits   as   follows:

   0x01 Right shift key is down
   0x02 Left shift key is down
   0x04 Ctrl key is down
   0x08 Alt key is down
   0x10 Scroll Lock is toggled
   0x20 Num Lock is toggled
   0x40 Caps Lock is toggled
   0x80 Ins is toggled