SCBStatus
status = inw(ioaddr + SCBStatus);
outw(status & 0xfc00, ioaddr + SCBStatus);
s1 = inw (ioaddr + SCBStatus);
s2 = inw (ioaddr + SCBStatus);
status = inw(ioaddr + SCBStatus);
intr_status = inw(ioaddr + SCBStatus);
outw(intr_status, ioaddr + SCBStatus);
inw(ioaddr + SCBStatus);