Sun external SMD cables
aperry at snowmoose.com
Sat Feb 15 01:11:37 CST 2020
On 2/14/20 1:54 PM, jim stephens via cctech wrote:
> On 2/14/2020 6:09 AM, Alan Perry via cctalk wrote:
>>> On Feb 14, 2020, at 04:15, Liam Proven via cctalk
>>> <cctalk at classiccmp.org> wrote:
>>> On Thu, 13 Feb 2020 at 19:06, Alan Perry via cctalk
>>> <cctalk at classiccmp.org> wrote:
>>>> I supplied part numbers. How can I be more specific?
>>> Oddly, some of us do not have a mental look-up table of Sun part
>>> numbers. In fact I think I can safely say that I could not identify a
>>> single cable of any form for any machine ever made by its part number.
>>> If you can, good for you.
>> I read the label attached to the cable.
>> I could tell you what connectors are at each end of the cable, but I
>> couldn’t tell you how they are wired together and, having no docs on
>> the cable or an example to check, am dependent on the part number to
>> tell me that.
> The SCSI spec and cabling have a specific way that the conductors have
> to be rolled to make a round cable. Each cable type has a recommended
> way that signal and grounds should be paired and in what proximity in
> the cable.
> For SMD I never saw a formal spec with as much detail as the SCSI spec,
> and I don't know if they standardized the cabling. Mainly to speculate
> about whether you can use a generic 25-25 or 37-37 straight thru.
I opened up the drive pedestal chassis. At the panel, a 60-pin ribbon
cable is split between the two D-sub connectors, 36 (with the #1 pin) on
the 37-pin D-sub and 24 on the 25-pin D-sub. The ribbon cable disappears
into the chassis, but there are two 60-pin ribbon cables come out, one
connected to each drive.
As far as the data connectors, I can only access the connector on one
drive. On the drive is a 26-pin IDC connector. The ribbon cable attached
to the connector is 25-pin and each drive has it own 25-pin D-sub on the
> I suspect the 25-25 would be sensitive to the type of conductor pairing
> and fabrication would work. The 37-37 bus connector probably would work
> with looser electrical specs to substitute in different cabling.
> Also just to make things more entertaining on the Oracle site for sun
> hardware they are using the term "Storage Module Drive" to refer to 6g/s
> SAS drives installed in individual blades for a blade server system. So
> the term appears frequently in their online docs, and including old
> documents and current documents.
When I was searching the Interwebs by part number, I found something
that categorized the cables as SAS cables, even though the official name
associated with the part number says SMD.
> Here's one example of that term on a page
> If I'm not far off base, I ran across two vendors who may have made the
> controller if they aren't sun, Interphase, and Xylogics. Also an
> article referred to the Sun boards as Eurocard from Xylogics. Xylogics 753.
The SMD controller is a Xylogics 451. It is a Multibus card, so there is
a Multibus-VME on the VME board between it and the backplane. The
control connector is a 60-pin IDC to ribbon cable split between two
D-sub connectors as above. The data connectors is as above, 26-pin IDCs
to 25-pin ribbon to 25-pin D-sub.
For grins, I tried powering up the drives. They came up and didn't make
>>> But if someone, say, told me "I need some SCSI cables: a MD50 to MD68
>>> cable, 2 × MD68 to MD68, an MD50 terminator and ideally a DB25 to
>>> MD50," then I would be able to say "yes, I have some of those".
>>> However, since Jim has been a bit more forthcoming, it sounds like I
>>> can't help you.
>>> Liam Proven - Profile: https://about.me/liamproven
>>> Email: lproven at cix.co.uk - Google Mail/Hangouts/Plus: lproven at gmail.com
>>> Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven
>>> UK: +44 7939-087884 - ČR (+ WhatsApp/Telegram/Signal): +420 702 829 053
More information about the cctalk