SM-4 (CM-4), Soviet PDP-11/40 computer clone, developed in Moscow's INEUM (INstitut Elektronnykh Upravlyaushikh Mashin, leading R&D organization of Soviet MinPribor) in the second half of 1970s. Very popular in science and technology.

Standard package included 128 or 256KB core memory, tape puncher, two RK-05 changeable 2.5MB disks and two RK-05F fixed disks, two TU-10 drives and Videoton VDT-340 terminals (VT-52 non-compatible).