HPIB HDA low-level format?

Is there a way to get an HP-IB disk unit with an ST412 or ESDI type HDA inside to perform a low-level format? I think this is what 'mediainit' is maybe supposed to do (based on being able to change the interleave) but I don't see any way to map bad blocks (etc.) using it. The -r 'recertify' option is apparently only valid for tape. I have a 7946A with a Vertex V170 that needs some new blocks marked bad. There's nothing on it I need to keep, but if I use 'mediainit' on it, it fails pretty quick with an I/O error. From the sounds it makes, it's hitting the first defect (at block 64) and giving up. # ioscan -f Class H/W Path Driver H/W Status S/W Status ================================================= hpib 7 98624 ok(0x301) ok disk 7.0 cs80 ok(0x220) ok tape_drive 7.0 cs80 ok(0x220) ok serial 9 98626 ok(0x10) ok scsi 14 98265 ok(0x313) ok disk 14.2 scsi ok(0x202) ok lan 21 lla ok(0x30f) ok # mediainit -v -i 1 /dev/rdsk/c7d0s0 mediainit: initialization process starting mediainit: locking the volume mediainit: performing a describe command mediainit: running diagnostics mediainit: initializing media mediainit: initialize media command failed - I/O error # I know it's doing something to the disk because the data that was in the first 64 blocks is now zeroed out. # dd if=/dev/dsk/c7d0s0 count=64 | od -x 0000000 0000 0000 0000 0000 0000 0000 0000 0000 * 64+0 records in 64+0 records out 0100000 # dd if=/users/bear/7946A.dd count=1 | od -x 0000000 0030 7375 2e72 0032 0000 0200 0000 0000 0000020 0000 0100 0000 0000 0000 0000 0000 0000 0000040 0000 0000 1190 1202 0644 0000 0000 0000 0000060 0000 0000 0000 0000 0000 0000 0000 0000 * 64+0 records in 64+0 records out 0100000 # ok bear. -- until further notice