It's arguably a continuation of MK-85, which if you go mad with soldering could be upgraded with enough RAM and disk to run UNIX V6 or V7 - as the pocket "programmable calculator" had essentially MicroPDP-11/73 or MicroPDP-11/83 on a chip, including the MMU.
And the CPUs weren't clones, they were in-house design by Elektronika that had to adapt by decree to supporting PDP-11 instruction set and Q-bus.