In the realm of computing, we have witnessed the emergence of various Linux-based operating systems designed to operate across a wide array of hardware platforms. However, the latest project by innovator Dimity Grinberg stands out as one of the most intriguing examples to date. At first glance, the project features a printed circuit board (PCB) that houses three integrated circuits, which may not seem particularly remarkable. What truly sets this project apart is that all three chips are contained within 8-pin SOIC (Small Outline Integrated Circuit) packages, raising the question: how can a full-fledged Linux operating system function on such limited hardware?

The answer, as one might suspect, lies in the innovative use of emulation technology. Among the three chips on the PCB, two are readily identifiable: a USB-to-serial chip and an SPI (Serial Peripheral Interface) RAM chip. The real star of the show, however, is the processor, which is an STM32G0 series device. This processor boasts a robust ARM Cortex M0+ core, known for its efficiency and speed. What’s particularly fascinating is that this processor runs a MIPS emulator, a technique that has been showcased in previous projects, and is also capable of being overclocked for enhanced performance.

When overclocked to a frequency of 148 MHz, the emulator effectively mimics the performance of a MIPS processor operating at approximately 1.4 MHz. While this may seem slow by today’s standards, it is just sufficient to operate a version of Debian, a full-featured distribution of Linux, without resorting to a stripped-down version that prioritizes speed over functionality.

One of the ingenious aspects of this hardware setup is the clever engineering required to squeeze serial communication, memory access, and SD (Secure Digital) card connectivity onto such a minimal number of pins. Notably, the serial and SD functionalities share the same pins on the PCB. To prevent interference, a filtering mechanism has been implemented to separate high-frequency SPI activity from the low-frequency signals used for serial communication. While the potential applications for this unique machine remain somewhat unclear, it certainly represents a remarkable feat of engineering and creativity.