9 Nov
2010
9 Nov
'10
3:24 p.m.
On 11/8/10, Pete Turnbull <pete at dunnington.plus.com> wrote:
That also sounds familiar.
Ethan Dicks wrote:
That sounds somewhat familiar.
The arrangements I know of are...
RL8A - round cable with a ZIF end for the drive and a 2x20 "Berg" end
for the controller
BC80J, described as 13 twisted pairs. RLV11/RLV12 -
round cable with ZIF end for the drive and a 2x20 Berg
end for the controller, but a different DEC P/N than the RL8A cable
(not positive and if true, don't remember why it's different).
BC80M/KG. It's listed as 13 twisted pairs shielded. Was the BC80J not shielded?
Since I've worked with both cables (20+ years ago, mind you), ISTR the
Berg end of the BC80M has a bit few cm of flat braided shielding
sticking out, with a crimp-on end that can be bolted down to some
nearby RF shield, a feature not present on the BC80J. Not sure about
the nature of the cable material itself.
Anyone, please feel free to correct me or add additional info, but it
seems to me that these products were coming out near the time of the
FCC RFI regs, so the BC80J might be pre-FCC and the BC80M either
post-FCC or made in anticipation of preliminary standards. I remember
a lot of FCC-driven product change around the early 1980s, but I can't
be certain if this was that or if it was driven by internal DEC
engineering improvements.
Who knows? Perhaps it's a data-reliability improvement and not just a
compliance issue?
-ethan