Zagreb engineer Mišo Rabatić designed the educational tool Pitagora 2000, which was awarded a bronze medal at the 1988 EXPO. It served as a ruler, protractor, compass, calculator, and much more.
The Zagreb Computer Machines Factory (TRS) was founded in 1948 and produced calculators, computing machines, medical measuring instruments, printers, and similar devices.
The most famous calculator produced by TRS was the mechanical Calcorex Model 403, which was redesigned by the first graduated industrial designer in Yugoslavia, Davor Grünwald. His collaboration with TRS is remembered as highly successful and of exceptional quality.
Radio Industrija Zagreb was established in 1948 with the goal of manufacturing transmitters for broadcasting, but they quickly began producing televisions, speakers, and electronic components as well. RIZ's venture into the pocket calculator market was short-lived, with only five or six models produced from 1975 to 1976.
Due to the destruction of previous documentation during the privatization of the company in the early 1990s, it is difficult to say for certain, but it appears that all of RIZ's calculators were produced under imported licenses.