Cray J90 emulation page

Welcome to the Cray J90 emulator. Below you can see the status of the emulation engine. If it is running, you can connect to it, using one of the following methods:

Use user name crayusr and password seymour for guest access. Once you log in, you'll see a message detailing how to get a personal account should you need one.

The simulator gets restarted every day around 10 AM UTC time.

If you want to read about the story of this simulator or leave comments, check out this site:


Q: What is available on the machine?

A: Right now the machine runs Unicos 10. It has the language tools installed as well (C/C++/Fortran/ASM). On top of it, I've compiled some open-source programs for the platform: bash, mc, wget and lynq

Q: How can I get X11 working

A: There's no simple way. If you're willing to run an open X11 server on a public IPv4 address, open up port 6000 and set DISPLAY to your machine, maybe it works. SSH X forwarding doesn't work at this point

Q: How can I exchange files with the machine?

A: Mainly ftp and wget. You can connect to the FTP server running on the simulator to transfer files or use wget on the machine to access HTTP (not HTTPS!) servers.

Q: How fast is the emulation?

A: Not very fast. It emulates a dual-core system, where the smallest J90 sold had 8 processors. Each processor emulation executes somewhere around 7 million instructions a second (for floating-point math and vector operations, much much less) where the real system was running at 100MHz, issuing up to one instruction per clock cycle