Yep, and it's one of the very few systems that can survive a power fail intact. I had a colleague who worked Friday nights at a company in North San Jose with a Truck Stop nearby with, erm, rough parties resulting in inebriated truckers. Unfortunately, the transformers for the industrial park (at that time) were on a platform on a triple pole monstrosity, such that said truckers would occasionally back into them, the resulting power fail taking down the business park.
My colleague earned the name "Powerfail". The HP3000s (two series 68s) would come back just fine. After the third iteration of this, PG&E finally bit the bullet and put in an underground substation.
The 3K was a really good box; ironically, the AS/400 was IBM's answer to it. Good to see that folks are still homesteading it. Still I worry about 2027 (of course the ux folks get the same issue in 2029?).....