* 3,4,5,6,7,10,11,14,15 : ISA dev IRQs
* 16-31: reserved
* 32 : keyboard int
* 33 : frame int (50/200 Hz periodic timer)
* 34 : sample int (10/20 KHz periodic timer)
* 3,4,5,6,7,10,11,14,15 : ISA dev IRQs
* 16-31: reserved
* 32 : keyboard int
* 33 : frame int (50/200 Hz periodic timer)
* 34 : sample int (10/20 KHz periodic timer)