Originally Posted by
grumpyoldman
The inter board wiring was random, no harness arrangement other than for power supply. Cross talk was even considered by the design engineers then. Wire wrapped in 30awg OFHC single core cables.
Days
( guessing you meant "Cross talk was
not even considered"
The inter board (backplane I surmise) random wiring may be what allowed it to work.
"Way back when" I used wire wrap proto boards (socket for each IC) and found out the hard way that neatly bundled routing, Manhattan no direct cross country, greatly increased crosstalk compared to random 'rats nest' routing.
I once made everything start working by dropping a single ferrite bead over the clock driver pin (before adding the wires) to slow edge rate enough to damp reflections.
This was with a 66Mhz clock which is the upper limit for wire wrap.