The PETR microcomputer was designed as a universal microprocessor kit that was used to create a small control computer. The main goal of its development was use in polytechnic education, and therefore it was delivered in the form of a kit, which users could assemble themselves and then program like a regular microcomputer.
The authors of the project focused on the microcomputer having a simple architecture, but at the same time enabling the control of real devices such as models, measuring and evaluation devices, signaling systems or railway tracks. The overall technical and structural solution of the kit was adapted to this purpose, while the emphasis was placed on the lowest possible price. Therefore, many functions were implemented by the control program, not by hardware.
The PETR kit was based on a single-chip microcomputer of the 8048 series. After the first tests, it became clear that the circuit solution was promising, which led to a redesign of the control program with the aim of increasing the universality of the kit's use. This allowed users to add their own control programs to the original circuit solution for more complex applications such as heating automation or home security. The PETR kit could thus be used not only for teaching, but also as a basis for specific practical projects.