Recreating an Obscure 8-Bit Soviet Computer with an FPGA

We’ve seen a growing interest in retro computing in recent years, with a corresponding response from manufacturers happy to cater to a new market. In the world of gaming, the NES Classic, SNES Classic, and Sega Genesis Mini proved to be very popular. THEC64 Mini filled a similar niche for 8-bit computing fans. But those releases were only feasible because the systems already had huge fan bases. Svofski knew there wasn’t any chance of his favorite computer receiving similar treatment, so he’s building his own Vector-06C Mini.

The Vector-06C (“Вектор-06Ц” in Russian) was an 8-bit home computer released in 1987 in the USSR. Unlike many of the most popular Soviet home computers of the 1980s, it wasn’t simply clone of a Western computer like a ZX Spectrum or Commodore 64. The Vector-06C may have lagged behind Western performance standards, but it was an original design that still has a loyal — though very small — enthusiast community. Svofski’s goal is to create a “mini” version of the Vector-06C, akin to THEC64 Mini, using modern hardware.

Svofski correctly surmised that no manufacturers were going to take on the challenge of designing and selling such a niche product, but the Vector-06C had unique capabilities that make it interesting today. Instead of running built-in software, like CP/M, the Vector-06C only had a small ROM chip that contained a bootloader. That let it launch software from a consumer tape deck or floppy drive. The Vector-06C’s video system proved to be quite versatile and allows for simulation and porting of games created for several other popular systems.

When Svofski first started this project in 2023, he planned to emulate the Vector-06C on an ESP32-S3 microcontroller. But that turned out to be inadequate for emulating the unique hardware. The Vector-06C had a KR580VM80A processor, which was a clone of the Intel 8080 that is possible to emulate. But the quirks of the Vector-06C made that more difficult to emulate than “regular” 8080-based computers like the Altair 8800 or IMSAI 8080.

The solution, which is still in progress, is to recreate the Vector-06C’s hardware on an FPGA. That is a Gowin GW1NR-9 FPGA chip on a Tang Nano 9K development board. It let Svofski take advantage of existing processor cores: one for the main CPU and one for the floppy controller’s processor. He originally used MikeJ’s T8080 CPU core, but then switched to a dedicated KR580VM80A core created by Vslav. Svofski modified a 65c02 floppy processor core to slim it down so it uses fewer logic units.

At this point, Svofski seems to have a system capable of booting, loading floppy software (from an SD card), and outputting video. He’s in the process of implementing a keyboard connection and audio output.

If Soviet 8-bit computers are your thing, then you’ll want to follow along with Svofski work to see his progress on the Vector-06C-Mini.