I used an old VAX for a while connected to full frontal internet with a Telnet port available. One of the cool things VMS had was a way to mirror the session fr

I used an old VAX for a while connected to full frontal internet with a Telnet port available. One of the cool things VMS had was a way to mirror the session from one terminal on another. It would watch while script kiddies would try to break in, only to be confused about what it was they had broken into when they succeeded. I'm sure you could do something like this by running VMS on simh and a vlan/pty and use your modem's port routing nat feature to send it telnet traffic. My go to "spare Linux server" environment has been RasPis for a while though since headless they are pretty cheap, with an actual x86 there are perhaps some interesting PCIe, PCI ,or ISA cards (depends on how old it is) that are fun. Setting it up as a media transfer station to move things off 5.25" floppy or 3.5" floppy or Zip disks or something can be a fun use as well.