There is SUPPOSEDLY a PLATO emulator available from SUBLIMINAL SOFTWARE
at PO Box 343 in Champaign, IL 61820-343. The price is $30. I talked to
one fellow who had written to them about it and never got a reply (He
didn't ORDER it, just sent a letter of inquiry). Can't find a phone number
listed but I do know that they did sell SOME of them because some people at
the U of I (where PLATO was born) are using it.