"Welcome to the CRAY J90 emulator."

In your browser, or over SSH, you can login to a shared Cray experience, and write some Fortran to run on two CPUs. It runs UNICOS, which is somewhat familiar to a Unix user, as noted in the motd:

How to use UNICOS?
It is a UNIX variant, so many of the usual commands work. You have bash for a shell, midnight commander as a file manager.
For programming, make, cc, CC, as, f90 and ld are your friend.
The interactive debugger (best with X11) is called totalview.
There is vi, vim and emacs for editing files.

There’s a visitor’s log book to append to.

via this interesting blog post about a timing bug which knocked the simulator out for a while: “Recently, I’ve noticed that the C compiler hung in the simulator.”


Somewhere in the piles of stuff where I work, there is (was?) a guide to writing efficient vector programs on Cray systems. I wonder if there’s an internet version…

Edit: I am amused to discover that I can still write working Fortran, but it’s Fortran IV. Luckily the f90 compiler doesn’t complain.