HP's -- slick stuff, high price. Great mechanicals

From: Bill Pechter <pechter_at_pechter.dyndns.org>
Date: Mon Nov 22 19:53:26 1999

> I'm not talking about I/O cables that are many feet long between a card and
> an external device, nor cables under two inches between just a few boards
> in the same backplane.
> I'm talking about using over-the-edge cabling for bussing signals between
> many cards in the same backplane, and that's what I was referring to the
> book about. This was done in the PDP-6, IIRC, and they decided that it
> was a maintenance nightmare. If HP somehow made this scheme work reliably
> and somehow kept it from being a headache to troubleshoot, I'd be interested
> in hearing how they did it. Obviously HP must not have thought it was
> a particularly great technique, since they generally aren't using it today.

The answer is get the machine down to 6 boards in less than a foot of
length with one aproximately 50 pin cable.

Worked fine.

They built a nice clean maintainable box. The PDP6 was a transistorized
machine with much more cables needed than the HP mini.

We're talking an early to mid 70's design vs. a late 70's to early 80's
design. Apples and oranges. The hp looked a lot cleaner than the
11/44 or 11/70 and seemed much smaller in number of boards and simpler
in layout of signals.

      Three things never anger: First, the one who runs your DEC,
      The one who does Field Service and the one who signs your check.
Received on Mon Nov 22 1999 - 19:53:26 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:32:30 BST