Graduate of NSU Created Free Educational Simulator “Yershov’s Computer”

The browser-based simulator “Yershov’s Computer,” in which a player without experience or special knowledge assembles a functioning 8-bit microprocessor from basic logic gates from scratch, configures peripherals, and writes a game for it in the built-in assembler, was created by a graduate of Novosibirsk State University. Dmitry Kalashnikov. Unlike abstract logic puzzles, its development is aimed at providing players with a realistic hardware experience. The interactive educational environment created by him is intended for schoolchildren and first-year university students, and can be used in educational institutions of various levels. The basic version of the simulator is free for self-study and available by the link.

— The project title reflects its main objective — to assemble a fully functioning computer with one’s own hands, step by step. Individual units and gates, like pieces of a construction set, come together to form a processor capable of running real programs. I named my project after academician Andrey Petrovich Ershov — a pioneer of domestic programming and the creator of the first school curriculum in computer science, — explained Dmitry Kalashnikov.

Training in the simulator is based on the bottom-up principle and starts with the classic trio of gates (AND, OR, NOT), which is much closer to university-level circuit design courses. The main difference is the honest work with “hardware.” The player does not just connect abstract blocks but configures the peripherals with their own hands through Memory-Mapped I/O, uses an address decoder, and resolves bus conflicts. Step by step, by constructing adders, memory flip-flops, and an ALU, they progress to creating a full-fledged Harvard architecture.

No prior knowledge is even required for this; the process can literally be started from scratch — the game includes a textbook with theory and a component reference (Datasheets). And the internal economy of transistors, which encourages self-assembly, turns “Yershov’s Computer” from a simple constructor into a real interactive course. Players earn currency called “Transistors” for independently completing 47 levels, while using auto-assembly results in a penalty. This stimulates deep engagement in the process.

— This system works simply: you assemble a circuit from logic elements (AND, OR, NOT gates, multiplexers, flip-flops) directly on the canvas in the browser, connecting them with wires. The built-in validation system automatically compares the behavior of your assembled circuit with the target truth table for the current level. As you progress through the levels, new, more complex components unlock. Small circuits are packed into chips, and tasks become more complex up to writing programs for your own processor in assembly language. — explained the developer.

The idea to create an interactive simulator came to Dmitry Kalashnikov from observing global educational trends. Among them is the program “One Student One Chip” (abbreviated YSYX). This is an advanced educational initiative aimed at training top-class specialists in computer systems. Its main principle is that every student must go through a full cycle of processor design and tape-out (release of a finished chip) during their studies. In Russia, there is no such initiative yet, but the need for it is immense. The “Yershov Computer” simulator has been developed in Javascript on the NodeJS server.

— Initially, I wanted to create a free project to support domestic engineering education. The main mission of my development is to make computer technology stop seeming like a complex, incomprehensible “magic.” Understanding how the processor works on both a physical and logical level lays a fundamental foundation for future engineers, programmers, and IT professionals.-specialists. The “Yershov Computer” was created so that this complex path turns into an engaging and visual process, because if “programming is the second literacy,” as Andrey Petrovich claimed, then understanding the hardware architecture of a computer is knowledge of its fundamental alphabet, necessary for truly deep mastery of this science. I believe this process should begin at school. If a child assembles memory, an arithmetic-logical unit, and makes them execute code with their own hands (even if virtual) from the simplest components, the fear of the “black box” of the system unit will disappear. Therefore, my project is designed to be intuitively understandable even for beginners, while being sufficiently deep for specialized tasks., — said Dmitry Kalashnikov.

There are currently no strict analogs of the simulator I developed, “Ersov’s Computer,” either in Russia or abroad. The cult game NANDgame, developed based on the popular university course “From Nand to Tetris,” is relatively close to it, but it implements a different concept and lacks gameplay.

— N ANDgame is a beautiful minimalist puzzle where the entire architecture is assembled from a single NAND gate. It is a neat mathematical trick, but real engineers do not design this way. The “Yershov Computer” simulator pursues a different goal: to provide the player with a highly realistic engineering experience and a solid educational foundation. There is also another game — commercial — Turing Complete, but it is more of a puzzle where each level is an individual task., — added Dmitry Kalashnikov.

The main difference of the “Yershov Computer” from these two products is the use of a single computer throughout the entire course and the gradual change of the abstraction level: gates, modules, Verilog, and architecture.

The simulator is intended for schoolchildren who find the standard computer science textbook insufficient and want to go beyond the school curriculum, as well as for students in the early years of technical specialties — for practice in computer architecture and circuit design. “Yershov’s Computer” will also be useful for all enthusiasts interested in understanding how a computer really works — at the level of ones, zeros, and transistors.

The developer is confident that his platform offers extensive opportunities for teachers as well: it integrates excellently into computer science, discrete mathematics, and computer architecture courses. For course implementation, a methodological guide for teachers is available (course philosophy, hardware platform, debugging tools), a pitch presentation for school administration (value, results, career orientation), and technical specifications for the Ershov Board lab board (pin-mapping, components, Ershov Loader). In the future, there will be an option to create virtual classes, which implies convenient distribution of students or schoolchildren into groups and issuing individual versions of assignments. Automatic evaluation (Autograder) is provided: teachers will no longer have to manually check hundreds of screenshots—the system will run students’ or schoolchildren’s circuits through tests and generate a performance record. There will be no need to monitor students to prevent copying from each other because they simply will not be able to due to the system’s built-in functions tracking build time, number of attempts, and the uniqueness of each player’s circuit topology.It is important that the instructor can adapt the simulator’s tasks and tests to the specific curriculum — from basic logic to complex microarchitecture. In addition, the teacher’s guide contains ready-made sets of laboratory works, historical references, and interactive element cards.

The project author continues to work on the learning environment, improving the interface, expanding the methodological base, and adding new features for teachers and students. In the near future, Dmitry Kalashnikov intends to smoothly transfer it from the virtual world to the physical one — onto real educational hardware. Then the educational game course he created will reach a logical conclusion. Currently, he is looking for educational institutions willing to implement the program he has developed. It is distributed for free — with his development, Dmitry Kalashnikov aims to contribute to the development of engineering thinking and to pay tribute to Academician Ershov’s school, which laid the foundations of domestic IT education.

Reference:

The creator of the “Yershov Computer,” Dmitry Kalashnikov, studied at NSU Higher College of Computer Science, then enrolled in Faculty of Information Technology of NSU, who graduated in 2008. Then successfully completed postgraduate studies at the A. P. Ershov Institute of Informatics Systems of the Siberian Branch of the Russian Academy of Sciences. Founded his own startup in the field of computational linguistics, aimed at creating products for literacy education in the Russian language. Occasionally works at NSU Startup Studios as a project tracker.

In the late 2000s, he lectured on computer architecture at the Higher College of Informatics of NSU. Dmitry Kalashnikov notes that at that time he really lacked such a simulator for training students.