Long ago in DEC PDP-11/70 days there were disk drives the size of washing machines to provide 80 or 100MB or so of storage. These all had removable disk packs, some had clear glass covers over the disks.
I used to like staring into the top of those while the disks were spinning so rapidly. I occasionally had the uncomfortable thought of what would happen if one of those disks broke loose at that speed. I also was haunted by the concept that one day I'd be removing one of those disks with the work of dozens of people on it and it would break loose from the cover (much like a big cake cover) and shatter on the floor.
Bizarrely, I now get much the same morbid thrill from staring through the top glass cover of my direct drive washing machine, which in spin cycle spins VERY fast and so looks very much like those old disk drives in action.
@lauren
Some of those old disk drives could be put into "washing machine mode" if you did a slow seek in followed by a fast seek out, repeat (they were on casters). Don't know which models had that "feature". Maybe the IBM disk drives.
@lauren
Long ago, I heard second-hand tales of mischievous CS students writing programs that would cause those drives, much like an unbalanced washing machine, to walk across the datacenter floor.
@tqwhite@lauren
I remember watching a compile, link of a Fortran program on a PDP11 that didn't have any disk, just a DECtape, which allowed positioning to an arbitrary block and overwriting a block on the tape. You can imagine how long this process took.
@PeterLudemann@tqwhite It was certainly possible to do on an 11/45, and at UCLA we had diagnostic DECtapes that were standalone as well. I still have a bunch of DECtapes around in those transparent blue cases. Nothing to read them with now. On the other hand, I have lots of punched paper tape rolls too, and those are actually a lot easier to read!
@PeterLudemann@tqwhite Yep. On top of the #1 ARPANET IMP at UCLA, there was a little cardboard box with a Mylar punched paper tape roll in it as an emergency boot for the IMP if all else failed. There was also a high speed paper tape reader up there. In my experience they were never used.
@lauren
Funny enough just yesterday we had an unbalanced load in the washer. The lid locks during operation so we were flummoxed as how to proceed. I figured out a procedure to unlock the lid. After much fiddling around with the load (towels) distribution we restarted the spin cycle. It took a while for the spin cycle to reach maximum speed. We dared not walk away until we were convinced the load was now balanced.
@jujube Some of these now automatically refill a number of times (up to five or more) to try rebalance automatically. Often this fails and after a certain number of tries they give up, having wasted considerable water in the process. Ironic for "low water usage" machines.
@lauren Not too long after that I worked with someone who had a version or 2 newer drive, RA-60, dropped the removable pack of platters and bent one or more. He then put the pack in 3 drives, trashing the heads on all 3. Ouch.
@kflanagan@lauren That was an expensive mistake. When the techs had to replace a drive platter we programmers would fight over who got to take it home as a trophy. Those platters were big and beautiful. Quite the conversation piece hanging on a wall.
@jujube@kflanagan At the original Stanford AI Lab (SAIL / SU-AI) there was a crashed I believe Librascope disk in the break room where the "Prancing Pony" vending machine controlled by the PDP-10 resided. It was almost 50 inches in diameter, with a big hole in the center. There was a small trash can residing in that hole. The entire thing served as a table. You could easily see the massive scratch in the surface that had taken the disk out of service.
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