>
> I don't know about this particular instance, but I picked up a bunch of
> Tandem-OEM'ed IBM drives that were all formatted to 520bytes/sec.  Dunno
> what the advantage of that configuration was, but I merely re-set the
> config to something more resembling a workable config (512b/sec) and
> everything worked OK.

520 bytes/sector config is in fact the same that 512 but 8-bytes of ECC is
not used by drives hardware but passed to/from machine.
>
> I know that when I read the datasheets for those drives, IBM claimed
> to support a range of sector sizes around 512b/sec (both smaller and
> larger) IIRC.