Embedded servo is rare (unheard-of) on ST412
interfaced drives simply
because the manufacturer has no idea how it will be low-level
formatted and thus where the sector headers will be. So no safe place
for the servo bursts on the data surfaces
*nod* That's what I would think: MFM should allow you physical access to
the heads to write the format as you see fit. So head positioning should
be mechanical, not servo based.
But a dedicated servo surface is very common on larger
That's why you often see an odd number of data heads. There is a head
on each side of each disk, but one is used for the servo.
This is a Maxtor 2190. The RD54 base disk. I've been having major
problems trying to format them on my RQDX3, I'll post that adventure in
a bit. In a nutshell the drives only partially format then error out. On
Dave G's MFM emulator all the tracks appear to be there.
Sounds like you've wiped that. No sensible way to
recover I'm afraid
Yep, with 15 yeads it had a servo platter that is gone. Oh well, it's
securely erased :-) I'll toss the drive, keep the electronics interface
and keep it in mind for the future.