ST506 on a modern system

From: Jerome Fine <jhfine_at_idirect.com>
Date: Sun Jan 10 20:54:45 1999

>Tony Duell wrote:

> > Can modern IBM PC clones easily handle ST506 hard drives?
> Yes
> > IE, is IDE a superset of this? Or does one have to find
> > an ST506 controller board?
> And Yes.
>
> ST506 and IDE are totally different interfaces. The first main difference
> is that ST506 is a 'raw' interface - what you get at the connector is the
> raw data stream off the disk, while IDE is a 'formatted' interface - you
> get nice bytes/words from the sector you want.
>
> But the IDE interface registers look _exactly_ like the registers on a
> particular Western Digital controller - the one used on the original AT.
> So a modern system should be able to use that controller to talk to an
> ST506 drive. It should boot fine and it should work fine.

Jerome Fine replies:

I realize this may be a very dumb question, BUT if I have an ST506
Qbus controller (either DEC RQDX1,2,3 OR 3rd party compatible
like Dilog or Emulex), would it be possible to change the 34/20 pin
cables (NOTE: On the Emulex DM01, there is already ONLY a
SINGLE 50 pin cable which is split 34/8/8) and connect those
cables in some manner to an IDE drive? You seem to imply (I am
probably very wrong) that a IDE drive might be connected to the
same interface which would also accept an ST506 drive on the
Western Digital controller.

Just thought I would ask? Sometime a very dumb question
has a better result than we even might hope for. Sometime
about 6 months back, someone mentioned doing a Qbus
interface for the IDE drives, but that it would likely have to wait
until the copyright by DEC on the MSCP interface expires
in about 2 years since the $ US 100 license fee would be
prohibitive.

Sincerely yours,

Jerome Fine
RT-11/TSX-PLUS User/Addict
Received on Sun Jan 10 1999 - 20:54:45 GMT