No downloads sadly, but you can telnet into the virtual Cray.
bash-2.03$ ./d Dhrystone(1.1) time for 50000 passes = 3 This machine benchmarks at 16666 dhrystones/second
It does seem snappy though. I’d never used UNICOS before, but it’s really cool. Maybe more so for the ‘yes I have used a super computer’ feel.