Bitfields for OPTi 82C750 Vendetta (device 1) keyboard control:
Bit(s)	Description	)
 15	keyboard port read (read-only)
 14	keyboard port write (read-only)
 13	keyboard RESET CPUINIT
	0 = generate immediately
	1 = wait for halt
 12	keyboard emulation disable
 11-9	PIRQ3# IRQ generation
	000 = use interrupt trigger control register (offset 50h)
	001 = IRQ5
	010-101 = IRQ9-IRQ12
	110-111 = IRQ14-IRQ15
 8-6	PIRQ2# IRQ generation
 5-3	PIRQ1# IRQ generation
 2-0	PIRQ0# IRQ generation
SeeAlso: #00939,#00941