+# sc #sectors/cylinder, nc*nt default
+# su #sectors/unit, sc*nc default
+# se sector size, DEV_BSIZE default
+# rm rpm, 3600 default
+# sf supports bad144-style bad sector forwarding
+# sk sector skew per track, default 0
+# cs sector skew per cylinder, default 0
+# hs headswitch time, default 0
+# ts one-cylinder seek time, default 0
+# il sector interleave (n:1), 1 default
+# bs boot block size, default BBSIZE
+# sb superblock size, default SBSIZE
+# o[a-h] partition offsets in sectors