ralph@uhheph.phys.hawaii.edu (Ralph Becker-Szendy) (02/05/91)
Question 1: On the VAXstation 3100 (and presumably its cousins, VAXserver 3100, microVAX 3100 and such), DEC uses a 68-pin Honda shielded connector as the external SCSI connector (there are two of them in this room, so I am certain of that). However, the SCSI-2 standard prescribes the use of a 50-pin high-density connector. I hear that Sun 4/3xx server systems have the same 68-pin connectors (unsubstantiated rumor, haven't seen one muself). Question: Is there a particularly good reason for DEC to use a non-standard connector, or is it actually some standard I missed ? What is the pin assignment on this connector ? Question 2: On the DECstation 5000 DEC uses a 50-pin connector high-density connector (verified, I walked around the one I am writing this on). I hear that SPARCstations also use this regular standard-conforming type. Slight simmering flame: Isn't it quite silly to stick to the standard on one product, not on the other ? It also makes life pretty hard on people like me who want to move periphereals back and forth, and always need yet another cable. Question 3: Internally, the VAXstation 3100 uses something very strange. The SCSI controller daughterboard has a 100-pin high density connector which is exactly the same size as a 50-pin square ribbon cable connector (but with pins on a 50x100 mil grid). The cable harness consists of a loop of 50-pin ribbon cable, both ends of which are seperately terminated in this 100-pin high density connector, whereas the connectors for the disk drives are standard 50-pin connectors (with a 100x100 mil grid), crimped on somewhere in the middle of the loop. Question: Why this arrangement with the 100-pin high density connector, what is the pin-out on it, where can I buy them (to make our own cables, whenever a disk drive gets added to a VAXstation), and why does DEC use yet another non-standard connector. Last question (this one is simple): Where can I buy SCSI terminators for the high-density 50-pin (Honda-type) connectors ? If possible I would prefer the new SCSI-2 termination style (110 Ohm to a ~2V low-impedande regulator), but the old style (220/330 Ohm divider would be OK). Where can one obtain the 50pin (and presunably 68-pin) high0-density shielded connectors in general ? I know only one manufacturer (Honda), which sells only through smaller distributors (I have found a few, none of them stock these connectors though), not through the big main-line distributors (like Newark, Allied, Hall-Mark). -- Ralph Becker-Szendy UHHEPG=24742::RALPH (HEPNet,SPAN) University of Hawaii RALPH@UHHEPG.PHYS.HAWAII.EDU High Energy Physics Group RALPH@UHHEPG.BITNET Watanabe Hall #203, 2505 Correa Road, Honolulu, HI 96822 (808)956-2931