[comp.sys.nsc.32k] Drive Enclosure..

news@daver.bungi.com (05/09/90)

I thought I would share with the group how I packaged the 9380S drives
which I purchased in the group buy a while back.  

However, first concerning the "Hi-Tech" 9380S deal, I totally agree with
Dave Rand when he says:

>Yup. I'm happy with the Miniscribe drives that we got. The price was great,
>the service has been fine, and they shipped the drives to the non-local
>folks, saving Karl a heap of trouble. All in all, we got a good deal!

Now, where to begin:  When the tower cases first came out I thought
they were the best thing since sliced bread.  However, I subsequently
have come to realize, at least in the less expensive versions, that the
design inherently provides inadequate cooling to the drive bay area.  
Consequently, I decided package the 9380S's in a separate stand alone 
enclosure.

At a local surplus house I was able to find a mini-AT 'like' case
for $10.00.  I say like because it was designed to minimize case 
height (5 inches) by using a special internal board arrangement.
The first drive simple mounts in the FH drive bay provided in
the case.  I mounted the second drive inside the case on 
3/4 inche stand-offs.  The standoffs screw into the holes
provided on the underside of the disk frame.  Next this assembly
is then secured to the bottom of case by machine screws through 
the case into the standoffs.

For a power supply I used one of the new PC 'mini' style switching
power supplies which are rated for 200 watts.  It measures 5.5"L x 5.8"W 
x 3.38:H and cost me $52.00.  The 12VDC serviced is rated at 8 amps.
In practice I am able to spin-up both drives at once with no apparent 
problem, but I suspect the current margin during this period is thin.  
In addition to price and availability, a standard PC type supply has the 
benefit of comming pre-wired so to speak (ie. ready to plug into the drive 
and AC-line).

The one surprise was that the disks ran VERY hot.  After they had run 
for an hour or so they were almost to hot to touch.  Prior to this I had 
only run the drives for short periods and had not noticed any significant 
heat build-up.  So I did the obvious and added a auxilary fan 
in addition to the small onr within the power supply.  The result is the
drives now run quite cool.  Quite frankly, I was amazed at the difference.
The original IO-card space on the rear of the case make an ideal place
to mount the fan.

To provide the SCSI interface, I mounted a 50-pin female Centronics
style connector on the lower rear surface.

Anyway, I am very pleased with the result, and hope that my brief
discription will help someone.  

One modification I am thinking about is adding the ability to select
SCSI ID's from a switch on the rear surface.  This reminds me,
does anyone know of a simple way in which the SCSI terminator
resistors could be 'inserted/removed' via a rear surface 
switch ??

Best regards,
johnc
-- 

cld@kd4nc.UUCP (Charles D'Englere) (05/10/90)

news@daver.bungi.com writes:


>I thought I would share with the group how I packaged the 9380S drives
>which I purchased in the group buy a while back.  

[*** rest deleted ***]

>One modification I am thinking about is adding the ability to select
>SCSI ID's from a switch on the rear surface.  This reminds me,
>does anyone know of a simple way in which the SCSI terminator
>resistors could be 'inserted/removed' via a rear surface 
>switch ??

>Best regards,
>johnc
>-- 

One way is to use the same terminators that Apple uses on its SCSI drives.
It fits on the end of the last SCSI device.

 ----------       ------------       ------------       -----------    ------
| UNIX Box |-----| SCSI DRIVE |-----| SCSI DRIVE |-----| SCSI TAPE |--| TERM |
 ----------       ------------       ------------       -----------    ------

I have made a little switch unit, that can be adaptive to any SCSI drive to
allow changing the address just buy pushing a button. This makes setting the
SCSI address very easy.

Good luck,
Charles

-- 
C. D'Englere Consulting          UUCP: {...!gatech,!emory}!kd4nc!cld
  Charles L. D'Englere             Phone: 404+3259074
    1409 Bronze Leaf Ct.             Stone Mountain, GA 30083