Int 2F Fn 1A3F  - Avatar.sys - Query Driver State                          [V]

   AX = 1A3Fh (AL='?')
   ES:DI -> buffer
   CX = length of buffer in bytes

Return: CF clear
   CX = actual size of returned info

Note:  the returned information consists of multiple letters whose meanings
     are described under AX=1A21h

See Also: AX=1A00h/BX=4156h,AX=1A21h,AX=1A44h