External MFM/ESDI?

Well, I have a bunch of open expansion space in my RK07
cabinet, and I
was thinking of somehow mounting the ESDI disks inside it. 
What sort of
products exist for mounting these disks externally, probably
in a
seperate cabinet from the controller?

> 
> Well, I have a bunch of open expansion space in my RK07
cabinet, and I
> was thinking of somehow mounting the ESDI disks inside
it.  What sort of
> products exist for mounting these disks externally,
probably in a
> seperate cabinet from the controller?

IIRC the maximum cable lengths, certainly for the ST412
interface, are 
quite short. Probalby not long enough to put the drives in a
separate 
rack cabinet. 

On my PC/XT, I have 2 5.25" floppy drives in the CPU
box. So no space for 
hard dirives. The machine sits on top of another box that
contains a pair 
of 3.5" floppies and a couple of ST412-interfaced hard
drives. The former 
are linked to the external floppy connector on that card. I
made up 
special cables from the hard disk controller's headers to
D-connectors 
(DC 37 for the control lins, DB25 for the data lines), then
cables from 
those connectors to the drives themselves. The first set of
cables were 
fed out thtorgh a slot the hard disk controller's blanking
plate, the 
conneectors being cable-moutned only. This works fine, but
the cables are 
only about 18" long total.

-tony

"Wolfe, Julian " <ISC277CLCILLINOIS.EDU> wrote:
> Well, I have a bunch of open expansion space in my RK07
cabinet, and I
> was thinking of somehow mounting the ESDI disks inside
it.  What sort of
> products exist for mounting these disks externally,
probably in a
> seperate cabinet from the controller?

Especially as you're looking for something vaguely DEC-ish,
in the late 80's/early 90's TRIMM made a rack-mount box that
looked a lot
like a BA23 but held four full-height 5.25" hard
drives. It
came with your choice of transition panels for SCSI or
MFM/ESDI.

And it even used DEC drive skid plates .

ESDI cabling is differential for all high-speed signals, so
you
can get a fair amount of length on it especially if you use
Twist-N-Flat.

While there were some PC-clone-oriented ESDI drives that
were
basically just warmed-over MFM drives, there were also large
number
of truly heavy-duty ESDI drives made for storage arrays in
the late 80's
through the early 90's. The Hitachi ones are particularly
heavy-duty.
When these hit the surplus market in the mid-90's I was in
heaven!

Tim.