That was the first 64-bit RISC CPU, indeed. I think we can also claim first 64-bit CPU - but not 100% sure.
I thought it was the DEC Alpha which was the first commercial 64-bit CPU?
There were 64-bit CPUs long before there were 64-bit microprocessors. I don't know what the first was, but the IBM 7030 was a 64-bit machine in 1961. (My first computing job, as a co-op, involved testing a UNIX emulation environment for the 64-bit Control Data 180 series, in 1985.)
Well, Alpha and MIPS (and some supers before them) had 64 bit addressing to handle more than 4 GB of address space. The 7030 had just a handful of memory and no vm, through it did have a 64 bit word size. ARM and x86 have been able to handle 64 bit numbers without anyone claiming they're 64 bit.
Okay. The Cyber 180 for instance had 48-bit addressing.
The CDC 180 sounds pretty interesting from the WP article, and, I agree, 64-bit. So not just supers then.