> Sun did the obvious thing: within a shoebox, they crimped DB-50s onto
> each end of a 50-conductor ribbon cable (the connectors labeled "scsi
> in" and "scsi out") and a 50-pin header onto the middle, then connected
> the header to the SCSI controller.  (It's easier to think of it this way
> than to figure it out by looking at connector pin numbers, because the
> connector pin numbers don't correspond to a linear arrangement of
> conductors on a ribbon cable.)
> 
> I do not know whether this is "standard" or not, but every DB-50 SCSI 
> connector I've ever seen (some from Sun, some from other sources) was
> wired this way.

It is at least a de-facto standard, however I have seen one exception:
an old Novell disk box containing an Adaptec ACB-4000 SCSI=>MFM bridge
board and two 5-1/4" full height Ampex 20MB disk drives (with a power
sequencer so the drives wouldn't overload the power supply by both
trying to spin up at the same time -- this thing is _really_ old).
They connected the pins of the DB50 to the numerically corresponding
cable positions, using a small PC board with a PC-mount DB50 and a
2x25 header for the internal cable.

I'm still using the box and its original power supply, with totally
different contents and normal SCSI/DB50 wiring.