5. Compact Flash Reader Writer IO DATA USB SMRW 
http://www.iodata.co.jp/products/pccard/2001/usbsmrw.htm 
umass0:              SM Reader   , rev 1.00/1.00, addr 3 
da0 at umass-sim0 bus 0 target 0 lun 0 
da0: < SM Reader 1.04> Removable Direct Access SCSI-0 device 
da0: 650KB/s transfers 
 
  port 2 addr 3: power 100 mA, config 1, product 0x0220(0x0220), vendor 0x090c(0x090c), rev 1\
.00 
 
 sysctl -w kern.cam.da.no_6_byte=1 をすれば問題なく動作