I'm familiar with ITS, but haven't heard this before, and am highly skeptical of any connexion with PRIMOS. The Wikipedia article on PRIMOS says "Legend has i

I'm familiar with ITS, but haven't heard this before, and am highly skeptical of any connexion with PRIMOS. The Wikipedia article on PRIMOS says "Legend has it that the unusual choice of FORTRAN for the OS programming language had to do with its history. Allegedly, the founders of Prime had worked for Honeywell on a NASA project. However, Honeywell at that time was uninterested in minicomputers, so they left and founded Prime, taking the code with them." ITS was written at the MIT AI Lab in MIDAS assembly language.