[rescue] Anyone have some 50pin SCSI HDD's lying around?

Scott Quinn saquinn624 at aol.com
Tue Nov 9 10:39:44 CST 2010

Message: 8

Date: Mon, 8 Nov 2010 10:13:11 -0800

From: "Sheldon T. Hall" <shel at artell.net>

To: "'The Rescue List'" <rescue at sunhelp.org>

Subject: Re: [rescue] Anyone have some 50pin SCSI HDD's lying around?

Message-ID: <3537BCD41F744C5B92D44D8E29CD2F3C at artell.net>

Content-Type: text/plain; charset="us-ascii"

Quoth Christopher Purdy ...

> Just picked up my new Onyx yesterday (Thanks Dan!!), and the

> HDD was toast..  I only had a 2 GB 50 pin drive.. anyone have

> a 9GB or better drive lying around I could snag?  I'm happy

> to pay shipping plus a couple bucks for your trouble.

Big 50-pin drives were never very numerous, so you might think about getting

appropriate adapters and using SCA drives.  I did that on my Challenge L and

it worked fine.  Big SCA drives are common and cheap.

Is your Onyx a _real_ one, not an Onyx2 or something?  If so, the original

configuration probably had HVD disks.  I don't know about the rack versions,

but on the desksides, there are two "chains" in the drive bay.  By default,

chain A is HVD and used for the disks, while chain B is SE and used for the

CD drive, etc.  Selecting which chain a sled uses is jumper-selectible on

the sled.

I passed my Challenge on to another collector over a year ago, and I hadn't

fired it up in a couple of years even then, so my memories may be


There is no reason that you should need 50-pin drives on a CHALLENGE/Onyx
system. The 50-pin sleds were for removable media, really - CD-ROM and tape
devices. Fixed disks were almost always 68-pin so they could take advantage of
the FAST-10/wide interface that the IO4 offers. Big 50-pin drives are rare as
Sheldon notes, and also generally getting pretty creaky compared to 68-pin and
SCA drives. 68-pin Everest sleds (CHALLENGE/Onyx) are pretty easy to find - I
have a box that came with my machine.

Configured from the factory the IO4 has one SE channel and one HVD channel,
but these can be changed based on what "paddleboard" adapter (not technically
a paddleboard I suppose, since it's 90*, but that word makes the most sense)
is installed on the IO4 SCSI channel output - green is SE and red is HVD.
Greens are hard-ish to find (especially since most expansion IO4s had all HVD
for remote Vaults), but if you want to stripe disks using XVM/XLV/LV/whatever
your IRIX supports they're much better than trying to rig up something with a
converter. If you're only using one or two drives at the same time you're
probably just fine with the single F/W 20-MB/sec SE interface (check on your
IO4 to make sure it really is SE!, and what channel it's connected to (based
on what cable plugs in where!!). On Shel's system (thanks, Shel - it's a fun
not-so-little box!) he disconnected the HVD channel just to ensure there were
no smoke-producing "mistakes", and unless you have a burning need for HVD I'd
recommend doing the same.

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