It took until 2019 for the US to give up the 8” floppies that ran its nuclear launch systems.

A 60 Minutes tour of the US nuclear control center in 2014 gave the public a glimpse behind the curtain of how the defense sector works. It also revealed that in the event that the US president ordered the launch of a nuclear warhead, the command would rely on 8-inch floppy disks and a 1970s era IBM Series/1 mainframe computer.

Rossi told C4isrnet that though the overall computer system is old, its age provides security.

“You can’t hack something that doesn’t have an IP address. It’s a very unique system – it is old and it is very good,” Rossi told the publication.

https://www.cnet.com/science/us-military-retires-floppy-disks-used-by-nuclear-weapons-system/