CAC_GET1
blks = CAC_GET2(dinfo.ncylinders) * CAC_GET1(dinfo.nheads) *
CAC_GET1(dinfo.nsectors);
bv->bv_level = cac_level[CAC_GET1(dinfo.mirror)]; /*XXX limit check */
CAC_GET1(dinfo.nheads) * CAC_GET1(dinfo.nsectors);
switch (CAC_GET1(dinfo.mirror)) {