DEMOS was a Soviet operating system derived from BSD Unix.
Commands in BSD are derived from English words. Did DEMOS use these same commands, develop their own commands but retain the Roman alphabet, or create entirely Russian commands in the Cyrillic alphabet? (The first would be the least amount of work, but the last would be the most acceptable to Soviet users.)
Were the commands lower-case (as most BSD commands are) or upper-case?
print chr$(255)
(observing the currency sign ¤ character in place of a $), you'll see Ъ.