[cctalk] Re: Drum memory on pdp11's? Wikipedia thinks so....

Bill wrote: The guy that took me on the tour said that the wall behind the drum had to be specially reinforced as if the drum exited the reinforced cabinet due to some kind of failure while at speed, it would have gone through any conventional wall like it was made of paper, and another wall which was the side of the building, and would have fallen 6 floors to the ground below, which obviously would have been disastrous. Apparently if there was a failure, due to the direction the drum rotated it'd come out the back of the cabinet rather than the front. I was also told that the drum cabinet had special mounting that was a large structure of steel beams in the mezzanine level beneath the datacenter that connected the mounts to the main support beams for the building, because the gyroscopic effects of the drum would have torn out anything else. The mounts had to be inspected every six months to look for cracks or any other sign of stress-induced problems. -Rick