Well, it would run on anything from a CDC 6600 up to (I think) the Cyber 850. However, Northwestern University created a Plato clone, also using the Tutor language, that could handle more terminal types than the classic Halloween terminal. I used to have the source code (in COMPASS) for MultiTutor... hopefully, the ex-so didn't trash it in '81 when she trashed a bunch of my stuff; it may be in the possession of a comrade. Look for CDC / Control Data instead... here's a link to a small pic of a Cyber 73: http://members.iglou.com/dougq/cyber73.gif CDC 6600 Serial Number 1, formerly owned by the Lawrence Livermore Labs, is now at the Computer Museum of History (or is that Computer History Musem) at Moffet Field in Kalifornia. Syntegra (the remnants of CDC) are still supporting NOS, NOS/BE, and NOS/VE, so I'm sure they've got one of the later Cybers running. Among other platforms, Plato was ported to the TI99/A. Well, I want one of the Halloween terminals (called that because the plasma display was orange on black) anyway, just to have. There have been a few incomplete attempts at starting an emulator for the CDC/Cyber machines... so far, they implement only the 60-bit modes of the early machines and not the later 64-bit mode needed to run NOS/VE. But someone needs to bring these disparate efforts together. This one will be *much* easier to do than the Multics emulator we often talk about on alt.multics.org. You might also post question in the USENET newsgroup comp.sys.cdc; it hasn't seen much activity lately, so go light a fire! regards, -dq