The 1980s are often called the golden age of personal computers. In the West, we had Commodore, Amstrad, Sinclair, Apple, and Atari, among many others. On the other side of the world, users had their own Galaksija – a home computer designed by Voja Antonić around a Z80 microprocessor. It was a true DIY project: more than 8,000 users built it before the company Zavod began selling pre-assembled units.
For those who grew up in the West, it was an exciting time. Some even called it the “revolution of personal computers.” Falling prices for electronic components, especially microprocessors, and the appearance of chips like the Zilog Z80 or MOS6502 led dozens of companies to sell home computers at prices that ordinary people could afford. Models such as the Apple II, the Sinclair ZX81, or the Commodore 64 became cult objects. But despite this explosion of brands and models, we knew little about what was happening in the Eastern countries.
While Western economies allowed millions of young people to buy a ready-to-use computer, the reality in other countries was quite different. The essential components, mainly manufactured in the United States, were not always available – for strategic reasons they were not exported to the “enemy” – and when they were obtained, their cost was too high for most people. Moreover, various laws prevented the import of computers into Yugoslavia. In this environment, the Galaksija appeared in December 1983, designed by Serbian inventor Voja Antonić. At the time he was 30 years old. He published the plans and all the information necessary to build the computer in a Yugoslav popular-science magazine that, fittingly, was also called “Galaksija” (Galaxy).
Ingenious Hardware
At the heart of this project was the Z80 microprocessor running at 3.072 MHz – the same chip that made most Sinclair computers, MSX, TRS-80, and even the Sega Master System and Sega Game Gear possible. In a remarkable display of ingenuity, Antonić’s computer, despite having advanced characteristics comparable to Western machines, used no specialized chips to generate the video signal or sound. The Galaksija took advantage of its tape-storage interface – ordinary audio cassettes – to generate digital audio effects.
The original design had no built-in speaker, but users could connect one externally. The video signal, which was very demanding on CPU resources because of its high frequency and delicate timing, was generated by the Z80 itself. The processor stopped executing the main program hundreds of times per second to “serve” the screen – a normal TV set, as was common in those years – to give the user a stable image.
Trying to keep the cost of the machine as low as possible, only 4 KB of ROM and 2 KB of RAM were used. Despite all its limitations – in some aspects it was even more limited than a Sinclair ZX81 – the magazine’s readers received the project with enormous enthusiasm, and it is estimated that at least 8,000 people built their own computer from the plans provided by Voja Antonić. The story goes that the editors had thought that, at best, about 100 people would dare to try it, but their calculations turned out to be extremely conservative.
Such success did not go unnoticed by regional entrepreneurs, and the company Zavod decided to market the Galaksija assembled and ready to use. It immediately became a success and settled in thousands of homes in several Eastern European countries. With its black-and-white resolution of 32x16 characters and a “semi-graphic mode” made up of 64 special characters, the Galaksija could not compete with the colorful and polyphonic computers of the rest of the world. But it still served to stimulate the imagination of many.
Enthusiasts learned how computers worked by observing the schematic diagrams of the Galaksija and reading Voja’s detailed explanations. Moreover, it became a great learning tool: many educational institutions acquired machines for their students. Thousands of young people, even from primary schools, learned computer science – including concepts of computer architecture and rudiments of programming – starting in 1984. Did you know it?
Learn more about Galaksija on Wikipedia.
