On Wed, 19 Jan 2005 04:27:41 GMT, "Don Kelly" wrote:
[snip]
|Cable lacing was (and is?) common for control wiring in control panels etc.
|in the power industry. In that case the signals involved were either 60Hz or
|DC and electromechanical relays and meters were used. coupling between
|circuits was a non-issue. However, with the advent of solid state devices,
|coupling became a problem. One major manufacturer considered a "diode tester
|to be a 15 ft lead to a switch or contactor cabled with a lead tied to the
|diode. - Open the switch- blow the diode. Wiring was neat and elegant and
|easy to follow. Circuit diagrams were accompanied by "back of panel"
|diagrams of the wiring to facilitate maintenance/repairs.

At Hughes, we didn't do "lacing", but used "lacing cord" (flat, waxed,
nylon) by the mile. We used spot ties, a precursor to today's cable
ties. These were clove hitches around the wire bundle, secured with a
square knot. In the production (missile) area, the ends had to be
cut, but in the engineering and test equipment area, we would "neaten
things up" by melting the ends into the knot with a soldering iron.

Since all the wire was teflon insulated, the ties could be slid along
the wire bundles during construction. While still a technician, I
once wired a programmer for some TOW missile test equipment. This was
back when the highest level integrated circuit was a 7490 decade
counter. The unit was basically a timing generator that had four PC
board card cages, 30 cards per cage, 44 pins per board, six 72-pin
cable connectors and a 24-column x 48-row patch panel. Damn near
every pin was used. Timing sequences were determined by ANDing and
ORing signals together via the patch panel and then setting or
resetting J-K flip-flops. So there was a lot of redundant wiring,
ie. one card cage might have 30 identical NAND gate boards.

We used ten wire colors, same as the resistor code, and prided
ourselves on having every wire bundle identical throughout its length
and to its neighbor. Black wire next to the brown wire next to the
red wire.....