VAXorcism for hobbyists

The owner of Slovenian company which worked with VAX/VMS has gifted me some vintage VAX workstations. They are MicroVAX 3100 and VAXstation 3100, which will join my collection of VAXstation 4000/90. They are being put on hold for the cold winter days, when I will use my time to play with them and upgrade them with recent NetBSD or GNU/Linux.