/B Causes QCACHE to load as a stand-alone UltraDMA driver with no
XMS memory. When /B or /U is given, /N is ignored. Other
switches above can still be used as needed. /B will "pass"
I-O unsuitable for UltraDMA to the BIOS. /B may lose much
speed! It is a "LAST chance", if absolutely needed, or for
diagnostic work.