Subject: Re: Hardware question - drive case.
To: None <cruller@unicom.net>
From: Bill Studenmund <wrstuden@nas.nasa.gov>
List: port-mac68k
Date: 06/15/1999 11:59:43
On Tue, 15 Jun 1999 cruller@unicom.net wrote:

> Hi all,
> 
> This will be used for NetBSD so it's only slightly off topic :).
> 
> I've got an old Mac II I was going to use as a netbsd IPNat box but am
> unwilling to spend _any_ money to upgrade it with an mmu.  Instead I
> would like to gut the box save for the power supply and turn in into an
> external drive farm that could hold 4 to 5 hard disks.  The power supply
> has a wire bundle that contains something like 5 red, 5 black, and I
> _think_?  one or two control wires(white & yellow) to turn it on & off. 
> Has anyone tried  something like this before?

Not with this case, but my IIsi uses a PCAT case for all its external
drives. :-)

> The case has internal mounts for 4 drives, so no problamo there. 
> I'd need to:
> 
> 1. get the power from the supply out cord bundle to a scsi drive power
> cord bundle and make sure the supply is giving 5v.

There should already be at least one disk drive power cable (it usually
has one red, two black, and one yellow wire). Fry's has power splitters.
Grab three of them, and your one plug will fan out to 4 plugs. ;-)

> 2. mount scsi plug on the back of the case and connect it to an internal
> scsi cable with many plugs on it. Maybe mount 2 different scsi plugs on
> back for use on macs, or NeXTslab.  On second thought an external cable
> could do that so only one connector is needed and could be mounted in
> the existing hole for a scsi connector on the box.

Note that the existing SCSI hole is a 25-pin hole. Don't use it as you'll
need a 25->50 adapter inside the box. Well, be fore-warned. :-) Oh, and
have a terminator inside the box.

If you make the ribbon cable, make sure the plugs are securely put
together. I made a cable with two 50-pin centronics plugs (what all the
external cables use) and a bunch of 50-pin plugs inside. The first cable
didn't work as I had the connectors a little crooked and hadn't used a
vice to squish them on. One Centronic plug was inside, and had a standard
terminator plugged in. The other was external and is how I hook the box to
everything else.

If you do this, make sure the centronics plugs will make it through the
case. I didn't the first time. :-)

> 3. determine how to turn the power on.  Would a momentary switch get it
> going or is a perminent connection needed.  I suspect there is an adb
> relay switch on the motherboard that trigers the power supply. A new
> scheme would be needed
> 
> 4. determine how to power off.

See the Guide to the Macontosh Family Hardware. It'll describe the power
plug on the II.

> 5. see about internalally mounting a CDROM, I've got a dremmel and am
> not afraid to use it. 

That's why I went with a PC case. :-)

> 6. Paint case bondi blu.....no...make that darth vader black w/a daemon
> logo.
> 
> Any Ideas or past anecdotes are welcome.

That's mine. Good luck. :-)

Take care,

Bill