31 Dec
2007
31 Dec
'07
11:57 p.m.
I have the same question. The ST506 and ST412 were
different
in the WrPrecomp signal being changed to a head select for
the ST412. I think he is looking at documents that state that he
needs a ST506/412 interface. This would be compatable with
just about any MFM drive made after the ST412.
There was a signal on some drives that came on the data cable.
I think it may have been a write protect but I don't recall
exactly what it was. The ST506 may have used this signal.
I'm not sure if this is what he is talking about.
Some, if not most, ST506/ST412 interface drives output a signal on the
data cable when that drive is selected. The idea was you could plug the
data cables into the controller in any order, and the controller could
determine which data connector to use, which receivers to enable, etc.
It's a pity few controllers made use of that!
I'm not aware of any write-protect signal on the data connector of any
such drive.
-tony