X3T9.2/90-104
Date:          July 5, 1990
To:            X3T9.2 Members
From:          John Lohmeyer, X3T9.2 Chairman
Subject:       High-Density Interconnection Working Group Meeting

I chaired a working group meeting June 19, 1990 from 10:00 a.m. until 12:00 
noon to investigate high-density interconnection issues for SCSI-2.  Almost 
all of the meeting was consumed in presentations from the following people: 

Company                  Name/phone          Foils     H/W
---------------------    ----------------    ------    ---
NCR                      John Lohmeyer       no        yes
                         (316) 636-8703

Hewlett Packard          Ed Silva            yes       yes
                         (916) 785-4204

Icontec                  Alan Haig           yes       yes
                         (408) 945-7766

Context Elect./Mold-Con  Roger Brickley      yes       yes
                         Bob Krzynowek
                         (413) 736-0371

CMS                      Wayne Douglas       yes       ?
                         (508) 580-0111

Connective Technologies  Fred Hengelhaupt    yes       yes
                         (802) 257-5242

Black Box Corp.          Bob Stevens         (Observe only)
                         (412) 746-6829

Amphenol                 Bill Sopchak        no        yes
                         (607) 786-4370

AMP                      Bob Whiteman        yes       yes
                         (717) 780-7481

Honda Connector          David McFadden      yes       yes
                         (708) 913-9566

Fujitsu                  Joel Urban          yes       yes
                         (408) 562-1722

3M                       Bob Herron          yes       yes
                         (512) 984-6807

Hirose Electric          Oscar Kornblum      yes       ?
                         (805) 522-7958

JAE                      David Shaff         yes       yes
                         (714) 753-2600

I have attached copies of the presentations which were made available to me.

Some issues that were identified are:

1.  NCR has experienced difficulties in finding cost-effective solutions for 
mixing high-density shielded connectors on cabinets with nonshielded low-
density connectors inside cabinets.  They are especially concerned about 
finding good solutions for the upcoming P cable.

2.  HP has experienced bent pin problems with the high-density connector when 
mounted horizontally with cables long enough to cause the connector to sag 
(droop).  They are considering using jackscrews instead of the clips shown in 
the SCSI-2 figures.  The cable droop does not cause loss of electrical 
continuity, but can deform the pins.

3.  Several cable assembly vendors pointed out that all of their customers 
for SCSI cables have unique requirements.  There is no such thing as "the" 
SCSI cable.

4.  One cable assembly vendor strongly recommended against using 2-56 
jackscrews presumably because they are too weak and break when over tightened.  
(Later in the week, I learned that the HIPPI standard will call out 2-56 
jackscrews with a minimum torque specification that can be met with stainless 
steel screws.  The 4-40 screws have interference problems.)

5.  Some customers are frustrated by slow delivery times on the high-density 
connectors.

6.  Bob Whiteman (AMP) showed a prototype 68-position daisy-chain high-density 
connector which uses 0.025 inch centerline ribbon cable.


No follow-up meeting is planned, however the HP issue concerning the retention 
mechanism will be included on the August X3T9.2 agenda.



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