Re: Umm. PDP-11s? good!
Little tip: there's money to be made if someone can make a converter to plug a new 2015 650W PSU into, that outputs stable noise-free voltage and current for an AT motherboard.
Converters are not exactly rare. Some more expensive ones even provide the -5VDC that started to be phased out in ATX1.2/ATX1.3 (or thereabouts). I can't speak for medical applications, but for ISA it was mostly (IIRC) used by sound cards and alike.