PCI224_DACCEN
outw(0, dev->iobase + PCI224_DACCEN);
outw(1 << chan, dev->iobase + PCI224_DACCEN);
outw(0, dev->iobase + PCI224_DACCEN); /* Disable channels. */
outw(devpriv->ao_enab, dev->iobase + PCI224_DACCEN);