SKALA monitored and recorded reactor conditions and control board inputs. It was wired to accept 7200 analog signals and 6500 digital signals. The system continuously monitored the plant and displayed this information to operators. Additionally, a program called PRIZMA processed plant conditions and made recommendations to guide plant operators. This program took 5 to 10 minutes to run, and could not directly control the reactor.
During the experiment of 26 April 1986, its safety features were suppressed. The system continued to partly function after the accident despite large structural damage to its room. Yuri Badaev tried to cover the hardware from radioactive water pouring down the ceiling and latter pulled memory boards to be taken into secure location. The system stopped functioning at around 5AM when emergency power went out.
This system dates back to the 1960s and was in use until 1995.