Reverse-engineering a VNA ECal Interface With Cynthion

Recently I’ve been working on a little reverse-engineering project, hoping to make some of my electronics test equipment more convenient to use.

Often when doing reverse-engineering, a general strategy that I follow is to make (informed) guesses about how something might work and then I go looking for ways to prove that right or wrong. In this project, Cynthion was really useful for that process as I could use it to emulate part of the target system, so that I could quickly and easily test out theories about the protocol.

This write-up goes over some of the progress I’ve made so far and...

Азотный лазер большой мощности: так ли он прост?

Несколько лет назад я отвлекся на другие проекты, которые не связаны с основным моим увлечением — старыми газовыми лазерами. Я бы и дальше откладывал возвращение к ним, если бы не предложение, от которого грех было отказываться — выполнить ремонт азотного лазера ЛГИ505.
В этой статье будут частично повторяться материалы из статьи про азотные лазеры продольного разряда, но также она дополнена массой новых данных. Я детально опишу, с чем довелось столкнуться в процессе выполнения этого заказа и развею бытующие среди любителей представления, что азотный лазер толерантно относится к уровню его конструктивного исполнения. Среди таких любителей был и я, потому полученные в...

lowRISC and SCI Semiconductor Partner to Create First CHERIoT Commercial Tapeout

...

lowRISC: A Decade of Bringing Open Silicon to Reality

...

Lampwork — декоративная стеклодувная техника. Часть 1. Работы подготовительные

Речь идёт об изготовлении в пламени горелки небольших декоративных вещиц из цветного художественного стекла на металлической спице, что радикально облегчает дело. Готовая работа, однако, имеет непременное технологическое отверстие от державки и цельностеклянное устройство. В основном это разнообразно украшенные стеклянные шарики-бусины для сборки дамской бижутерии, которые, впрочем, бывают настоящими произведениями искусства. Забава эта недешёвая, но, уже имея все её дорогостоящие компоненты, пройти мимо счёл бы преступной небрежностью. Опять же, лишних навыков и знаний не бывает. Читать дальше →

Neural Network Visualization

Going along with implementing a very size optimized neural network on a 3 cent microcontroller I created an interactive simulation of a similar network.

You can draw figures on a 8×8 pixel grid and view how the activations propagate through the multi-layer perception network to classify the image into 4 or 10 different numbers. You can find the visualizer online here.

Amazingly, the accuracy is still quite acceptable, even though this network (2 hidden layers with 10 neurons) is even simpler than the one implemented in the 3 cent MCU (3 hidden layers with 16 neurons). One change that led to...

On Linux MAINTAINERS file removal of Russian developers

I sincerely regret to see Linux kernel patches like this one removing Russian developers from the MAINTAINERS file. To me, it is a sign or maybe even a symbol of how far the Linux kernel developer community I remember from ~ 20 years ago has changed, and how much it has alienated itself from what I remember back in the day.

In my opinion this commit is wrong at so many different levels:

it is intransparent. Initially it gave no explanation whatsoever (other than some compliance hand-waving). There was some follow-up paraphrasing one paragraph of presumed legal advice that was given presumably by Linux...

Embracing the Future: New Omega2 Beta Firmware and Documentation Site

We’re excited to announce a major milestone in the evolution of the Omega2 platform. After months of development and community collaboration, we’re introducing a new beta firmware based on OpenWRT 23.05 and the modern 5.15 Linux kernel. This firmware provides a clean slate designed to make building your products and applications easier and faster than before.

To complement the new firmware, we’ve also launched a brand-new documentation site. This site is crafted to help you navigate the new features and enhancements with ease, offering comprehensive guides, tutorials, and reference materials.

Together, the new firmware and documentation site represent our commitment to putting...

Oral history transcripts: Pioneers of Taiwans Chip + PC industry

During the preparation of my current brief visit to Taiwan, I've more or less by coincidence stumbled on several transcripts of oral history interviews with pioneers of the Taiwanese Chip and PC industry (click on the individual transcripts in the Related Records section at the bottom). They have been recorded, transcribed and translated in 2011 by the Computer History Museum under funding from the National Science Council, Taiwan, R.O.C..

As some of you know, I've been spending a lot of time in recent years researching (and practically exploring + re-implementing) historical telecommunications with my retronetworking project.

Retrocomputing itself is not my main focus. I...

Back to Taiwan the first time after 5 years

Some of the readers of this blog know that I have a very special relationship with Taiwan. As a teenager, it was the magical far-away country that built most of the PC components in all my PCs since my first 286-16 I got in 1989. Around 2006-2008 I had the very unexpected opportunity to work in Taiwan for some time (mainly for Openmoko, later some consulting for VIA). During that time I have always felt most welcome in and fascinated by the small island nation who managed to turn themselves into a high-tech development and manufacturing site for ever more complex electronics....