They weren't very popular, first because of their cost, and secondly because they didn't produce very reliable, and, above all, very reworkable results. IF you designed the circuit right the first time and IF you constructed it right the first time, they were "OK." If you had to make changes, you were "circling the bowl."

Wire-wrap was not cheap. The sockets often cost more than the IC's, and the boards and wire weren't free either. On some boards, it wasn't so easy to use the connectors you wanted to use, and the wire, typically #30, didn't carry a lot of current, so if you used wired power connections, with the technology of the '70's, you might experience some impact.

Those same difficulties impacted other technologies, too. Multiwiere produced the densest, but least "fixable" circuitry. These 3M sockets were on the same order, as it was nearly impossible with them, to trace a wiring error. They were dense, though. That was one factor leading to their use, as the more popular "3-level" wire-wrap sockets wouldn't fit a number of backplanes without leaving a slot open. If you had six slots and needed to use two wire-wrapped circuits, you couldn't fit your project into the backplane with more than two PCB's. If, however, you used these 3M sockets, you could fit your circuit wherever a PCB would fit. That influenced some people.

Quite frankly, nobody I knew used 'em though some had tried 'em.

RE