[cctalk] Re: IBM backplane story was Re: Another 780 backplane story

On Jul 6, 2025, at 7:08 PM, Brendan McNeill via cctalk <cctalk(a)classiccmp.org> wrote: I’m loving these stories, those of us who were field engineers have many to share. I started out as an FE with CDC in the 1970’s here in New Zealand and then moved to Data General five years later. CDC was a very conservative, button downed company - For example, no new systems were installed until the complete spares kit had arrived, everything was properly documented. DG on the other hand was the wild west by comparison. The only thing that mattered was quarterly revenues. Sure, spare parts existed but not always where you wanted them to be located! One time I took a call for a disk related problem at a remote site on the West Coast of New Zealand. The customer had a DG commercial system like the one in this advertisement: https://www.youtube.com/watch?v=LPqqjRBqhHI and a couple of ‘zebra’ 100mb disks, of the washing machine size. The system disk had failed and they couldn’t reboot from it. Fortunately they hadn’t powered it off as the voice coil had gone open circuit. No spare parts of course, so I manually retracted the heads, powered off the drive, removed the voice coil and used a scalpel to cut away the former around the area where the external wires entered the coil. Re-crimped the wires, obtained some epoxy resin from a hardware store, and a couple of ice creams on a stick. Used the sticks as a ‘former’ to hold the epoxy resin. Half an hour later they were back up and running. The disk never failed again.