NOS 1 followed Kronos by providing the TELEX subsystem for interactive use. TELEX provided an environment modeled a lot after the ones found inside BASIC interpreters, namely, you issue commands like OLD, NEW, RUN, etc... In fact, that was TELEX's primary purpose in life. It also provided a "batch" mode where you would simply type control- cards one at a time. But most everyone use the interactive modes. As to the file modes being counterintutive, they're really not, once you hold you head the right way... Just as in DEC-10 or other BASICs, if you typed NEW, a LOCAL file was created. Anythying you typed following a line number because part of the local file's contents. Of course, if you type a program in, and didn't type SAVE prior to logout, the file would be lost because you hadn't made it into a permanent file (PFILE). But as I say, this was the same was most BASIC interpreter environments worked,,, -dq