DEC BC09J cable

From: Loboyko Steve <sloboyko_at_yahoo.com>
Date: Thu Feb 28 12:30:53 2002

Really, with care, you can do it with a vise with
rubber/wood pads for the jaws. Just keep everything
perpendicular. And watch the orientations on pin 1.
The connectors will definitely not "recycle" reliably
without extreme care. Most connectors will click when
100% tight. Don't undertighten, but don't overtighten
either on the vise.

Gotta tell a funny story: I was working for a computer
company in 1980 when I was to install the company's
first 5M Shugart ST-506 HDD in the country at a car
dealship in Nowhere, Wisconsin (100+ miles from the
office). Being a new piece of equipment, I had no
spares. So, I go up there and what was delivered there
didn't work. I examined the cabling and determined
that the cabling was made backwards. So, I call up the
home office in California. Talked to a French engineer
who obviously thought that I was an idiot about the
cable. He told me to take the cover of the drive off.
Naturally, I knew that he meant the drive subassembly
housing cover, but I waited a few moments, and then
told him that I got the cover off, was looking at the
drive spinning and head moving, and what should I do
now (remember, at the time, this was USD$500 OEM in
1980 dollars, and the drives were on serious
allocation). All I heard was "merde" "merde".

After he calmed down, he agreed with me that the
connector was backwards.

I spoke to the dealership owner at length about the
delicacy of the drive mechanism. No jarring the table,
no dropping, no vibration, don't forget to park, and
so on.

So, in the same breath, I asked him for a rubber
mallet to fix the cable with.

I did recycle the connector end in the field with a
rubber mallet, a pair of pliers, and my shoe heel as
an anvil! The locks on the connector were broken, but
as long and no one went inside the box it was OK. The
dealer got a good laugh out of the whole thing. As far
as I know, it worked until the equipment was
obsoleted.




--- Jerome Fine <jhfine_at_idirect.com> wrote:
> >Tothwolf wrote:
>
> > If you don't have an IDC press and this is the
> first ribbon cable you've
> > ever made, buy at least 2.5x the amount of cable
> you think you'll need,
> > and at least twice as many connectors. IDC
> connectors are somewhat fragile
> > when pressing onto ribbon cable, and without the
> proper press, you end up
> > damaging at least one before you get the technique
> down. Ribbon cable and
> > IDC connectors are both inexpensive, so it would
> be good idea to have some
> > extra. A vice and some small blocks of wood can
> press IDC connectors onto
> > ribbon cable in a pinch. Don't try to press the
> connector on by hand, it
> > won't work, and you'll break the connector. Also,
> don't use scissors to
> > cut ribbon cable. It frays the ends of the wire,
> and can short out the
> > conductors. If you don't have a flat cable cutter,
> (carefully) use a metal
> > straight-edge and an X-Acto knife to cut the
> cable.
>
> Jerome Fine replies:
>
> I thought I might add a few observations about the
> cables I have made.
>
> (a) I have worked only with 50-pin flat SCSI cables
> and the 20-pin/34-pin
> cables for MFM drives or floppy drives
>
> (b) I don't have an IDC press - I use a small vice
> with opposing heads
> that are about 2 1/2" * 1/2" - I have never bothered
> to add wooden
> blocks - the vice heads are undamaged and quite flat
>
> (c) I usually work with USED materials, i.e. not
> only old cables, but also
> salvaged header parts (connectors)
>
> (d) I use a very sharp scissors to cut the cables -
> when I inspect the
> cut cable end with a jeweller's loop, I can't
> remember when I have
> found any frayed ends or shorts between the
> different strands
>
> (e) Normally, I inspect the header parts
> (connectors) match-up to the
> cable with a magnifying glass (sometimes even a
> jeweller's loop) just
> before the parts are put between the heads of the
> vice
>
> On a VERY few occasions, I have jumpered some of the
> strands
> to each other when that was required. In a BA23 box
> with only
> 4 button switches, the READY line and WRITE PROTECT
> line
> needed for a second MFM hard drive (RD52) were cut
> out with a
> small X-Acto knife. Then I used the X-Acto knife to
> bare the
> corresponding strand from the first hard drive. I
> then soldered the
> two strands for the second hard drive to the
> corresponding strands
> for the first hard drive. While I could not remove
> the WRITE
> PROTECT status for both drives except by a re-boot,
> at least
> WRITE PROTECT was available for both drives when
> required.
>
> Toth, the above are not contradictions of your
> advice, just my
> experiences when I did not know how to do anything
> at all and
> used trial and error.
>


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Received on Thu Feb 28 2002 - 12:30:53 GMT

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