# Balanced ternary

I am working on a computer architecture principles lectures for our university; and as an assignment I'd like to propose to my students to build a simple programmable machine working in ternary. The main reason is fun: as a lecturer I must bring a bit of entertainment, otherwise I won't be listened to. Besides, it is important for historic reasons. Any further «why?!» questions will be answered «Because I can».

This page describes the very basics, it won't go beyond a simple ternary adder (and its hardware implementation). Stay tuned for more.

I chose the balanced ternary system: every trit represents one of three possible states, -1, 0 or 1. A very extensive description of this system may be found here.

• ## Android Robotics up to 2019: The real story; in 5 parts; part 5

This post is a continuation of the first, the second, the third, and the fourth parts of the real story of Android Robotics describing the field from the beginning up to 2019.
• ## Android Robotics up to 2019: The real story; in 5 parts; part 4

This post is a continuation of the first, the second, and the third parts of the real story of Android Robotics describing the field from the beginning up to 2019.
• ## Naïve Math: the Mendocino motor and Earnshaw's theorem

• Tutorial

# The problem statement

I was surfing the Internet the other day and a rather curious thing caught my mind: the Mendocino motor. It’s an extremely low-friction bearing rotor: the original one had a glass cylinder hanging on two needles, but the modern ones use magnetic suspension. It’s a brushless engine: the rotor has solar batteries attached to it, which generate current for the coils wrapped around the rotor. The rotor spins in a fixed magnetic field, the solar batteries getting exposed to the light source one after the other. It’s a rather elegant solution that’s very possible to recreate at home.

Here’s the video that explains how it works (in Russian):

But this video had another curiosity even stronger than the engine itself. In the video description Dmitry Korzhevsky writes: “You CAN’T replace the side support with a magnet! Don’t ask me about this anymore!”
• ## Android Robotics up to 2019: The real story; in 5 parts; part 3

This post is a continuation of the first and the second parts of the real story of Android Robotics describing the field from the beginning up to 2019.
• ## Android Robotics up to 2019: The real story; in 5 parts; part 2

This post is a continuation of the first part of the real story of Android Robotics describing the field from the beginning up to 2019.
• ## Android Robotics up to 2019: The real story; in 5 parts; part 1

Quite a long time ago, seven years ago to be precise, i wrote a series of posts describing the state of android robotics in the world. At the time i was a high school student, with a keen interest in android robotics, who absorbed a bit of knowledge from English, Japanese, Chinese, Korean and Russian internetz and wanted to spill it somewhere.

While the posts were not too professional, and not to my standards of today, they were worthy enough to get stolen and even get translated by unapproved English Habrahabr mirrors, and to this day, appear in searches.

After those posts were written, Habrahabr got split. Removal of everyone outside of pure coding who were considered «not cake enough» to Geektimes felt like an insult and so i left the platform. Yet, the website was reunited last year, and much to a personal surprise, fairly recently an English version of Habrahabr was released.

During all these years i managed to be kicked from one university, finished another with a thick thesis on «Usage of Robotics in Disaster Conditions», lived in the Republic of Korea for half a year, and most importantly, not only expanded my knowledge of android robotics in such ways that the Robotics folder on the main hard drive is now more than 300GB in size, but also expanded the knowledge via journeying and personally meeting projects of the past and present, creating quite a decent archive on Youtube and met not only with the robots, but the engineers and scientists as well.

While i am still nowhere to be a robotics engineer, (and in the daily life i attempt to be a traditional slice-of-life artist), i feel that my tiny gigabytes of knowledge might be worthy of sharing, and today on Habr i'm publishing the real story of Android Robotics from the beginning up to 2019.
• AdBlock has stolen the banner, but banners are not teeth — they will be back

• ## $10 million in investments and Wozniak's praise — creating an educational computer for children We interviewed Mark Pavluykovskiy — the creator of the Piper educational computer. We asked him about immigrating from Ukraine to the US, how he almost died in Africa, graduated from Princeton, dropped out of a doctorate in Oxford and created a product that deserved a praise from Satia Nadella and Steve Wozniak. In mid-October the Sistema_VC venture capital fund hosted a conference called Machine Teaching, where creators of various educational startups assembled to talk about technical advancements. The special guest was Mark Pavluykosvkiy, the creator of Piper. His company created an educational computer — a children’s toy that, using wires, circuit boards and Minecraft teaches programming and engineering to children. A couple of years ago Mark completed a successful Kickstarter campaign, got a couple of Silicon Valley investors on board and raised around$11 million dollars in investments. Now he’s a member of Forbes’ “30 under 30” list, while his project is used by Satia Nadella and Steve Wozniak, among others.

Mark himself is a former Princeton and Oxford student. He was born in Ukraine, but moved to the US with his mother when he was a child. In various interviews Mark claimed that he doesn’t consider himself a genius, but simply someone who got very lucky. A lot of other people aren’t so lucky, however, and he considers it unfair. Driven by this notion, during his junior year he flew to Africa, where he almost died.
• ## System in Package, or What's Under Chip Package Cover?

Transistor feature size is decreasing despite constant rumors about the death of Moore’s law and the fact that industry is really close to physical limits of miniaturisation (or even went through them with some clever technology tricks). Moore’s law, however, created user’s appetite for innovation, which is hard to handle for the industry. That’s why modern microelectronic products aren’t just feature size scaled, but also employ a number of other features, often even more complicated than chip scaling.

Disclaimer: This article is a slightly updated translation of my own piece published on this very site here. If you're Russian-speaking, you may want to check the original. If you're English-speaking, it's worth noting that English is not my native language, so I'll be very grateful for the feedback if you find something weird in the text.
• ## Progress and hype in AI research

The biggest issue with AI is not that it is stupid but lack of definition for intelligence and hence lack of measure for it [1a] [1b].

Turing test is not a good measure because gorilla Koko wouldn't pass though she could solve more problems than many disabled human beings [2].

It is quite possible that people in the future might wonder why people back in 2019 thought that an agent trained to play a fixed game in a simulated environment such as Go had any intelligence [3a] [3b] [3c] [3d] [3e] [3f] [3g] [3h].

Intelligence is more about applying/transferring old knowledge to new tasks (playing Quake Arena good enough without any training after mastering Doom) than compressing agent's experience into heuristics to predict a game score and determining agent's action in a given game state to maximize final score (playing Quake Arena good enough after million games after mastering Doom) [4].

Human intelligence is about ability to adapt to the physical/social world, and playing Go is a particular adaptation performed by human intelligence, and developing an algorithm to learn to play Go is a more performant one, and developing a mathematical theory of Go might be even more performant.

• ## Receiving shortwave faxes with your PC and an off-the-shelf receiver

• Tutorial

One of the many botched faxes

When most people hear «fax», they remember those clumsy hybrids of a telephone and a printer straight outta 80s (unless you're in Japan, of course — they're still common there). But did you know that a similar technology is used to provide ship crews with weather data when there's no Internet connection? And Kyodo, a Japanese news agency (they sure like faxes, huh), still broadcasts news like that. And we can decode all this stuff, too — given a receiver, an audio cable and some software.
• ## How to Painlessly Unite Art with Java, JavaScript, and Graphs or The Story Behind Creating an Interactive Theatre Produc

Last year 2018, a theatre production series called Tale of the Century was launched in Estonia. Throughout the year, 22 local theatres presented their interpretations of the past hundred years of Estonian history to the audiences. In the draw, the Russian Theatre was assigned the topic of the future of Estonia.

• ## Creator of while True: learn() on programming in game development, VR issues and machine learning simulation

• Translation

A few years ago I had a feeling that Oleg Chumakov (then working at the game studio Nival) was the most famous programmer in the game development industry. He was giving speeches, hosted Gamesjams and frequently showed up on the podcast How games are made.

When VR hit the market, Oleg was chosen to lead the company’s new department — NivalVR. But, as you probably know, VR didn’t quite take off as much as people expected.

I kind of moved to other to other things in life and stopped keeping up with game development for a while, but after getting into it again I noticed that things were looking up for Oleg’s team. Now it’s called Luden.io, and their machine learning expert simulator, while True: learn() became a huge hit in its admittedly small niche. Lots of cool stories are happening around the game and the team.

We decided to do an interview with Oleg, but I couldn’t stick to one topic — his life up to this moment has been, for the lack of a better word, “interesting”. He’s seen it all. And, to ensure that a programmer could talk about programming without fear of looking too “nerdy”, the interview was conducted by my friend, colleague and an experienced developer of its own fillpackart.
• ## How to milk cows with robots and make an industrial startup of it. The history of the R-SEPT development

• Translation

In 2017, the media heard a very interesting story about a startup that robotizes milking cows on industrial dairy farms. The company is called R-SEPT, and back then it received 10 million rubles of investment. But a year has passed, and there's still no news on what happened further. We contacted Aleksey Khakhunov (AlexeiHahunov), the founder of the startup, and discussed the development. It turns out that the whole year his team was getting the prototype of the robot into shape, and just a week ago they conducted their first field test on the farm.

Under the cut there's a story about a robotics student who grew up on his parents' farm, turned the University diploma into an industrial startup, as he collected the first manipulators with his friends, and then scaled up to the level of state programs for the robotization of agriculture. And the most important is how the iron hand of the robot and the machine vision are better than a living milkmaid.
• ## Info Desk: «Internet Archive» — history, mission and subsidiary projects

• Translation

Probably, there are not so many users on Habr who have never heard about the «Internet Archive», a service that searches and stores the digital data that is important for all mankind, whether it be the Internet pages, books, videos or other type of information.

Who manages the Internet archive, when it appeared and what is its mission? Read about it in the today's «Inquiry».
• ## I am a useless idiot, so I want to quit my job: 10 questions to a software developer, a pilot episode

• Translation

Hi there, Habr!

Remember the story of Steve Jobs and Dennis Ritchie? Without any intention to rekindle the debates or moralize on the subject, let’s face the truth: thousands of stellar techies live in the shadow, while their own stories are hidden in a dusty cupboard.

We, the Habr editorial team, are keen to tackle this injustice. From now on, we will regularly interview people who keep a low profile in media and social networks. So if you have anything to tell about yourself, get ready.

To give you an idea of what this will look like, we will lead the way. Click below to see 10 general questions we will ask every guest. For our pilot episode, the first guest to answer the questions was fillpackart. (This month I’ve had several quite good interview sessions with him, see articles one, two, three). Please read them, and if you make up your mind on telling your own story in a similar way, just send me or baragol a message.
• ## How to crack a self-service terminal and why 80% of them are under threat

• Translation
Author of the original post in Russian: frsamara

I always loved playing with things and testing them under all sorts of wacky conditions as a kid and even considered getting a job as a tester, but I never did. Nevertheless, I still like taking things made by someone else and poking them for vulnerabilities.

I remember, when first self-service payment terminals started popping around town, I saw one of them put up a browser window while updating, and the game was on — I broke it almost immediately. There’s been a lot of discussion about it since then and developers have started to pay a lot more attention towards security in these machines.

Recently, fast-food joints have started installing these terminals. Obviously, it’s quite convenient: just tap a couple of virtual buttons, place an order, pay with a bank card and wait for your number to show on the screen.

Also, nearly every big mall has these interactive boards with floor plans and information on various sales and discounts.

How secure are they?
• ## 286 and the network

• Translation
Author of the original post in Russian: old_gamer

I'm a ragman. I have a closet full of old hardware. From Boolean logic microchips in DIP-cases to Voodoo5. Of course, there's no practical value in all of this, but some people enjoy messing with old hardware. If you are one of them, I invite you under the cut, where I will tell you how the computer based on AMD 286 processor worked with a modern network, and what came out of it.
• ## The hard-to-catch bug in LittleBigPlanet

• Translation

Author of the original post in Russian: HotWaterMusic

The history of the world's gamedev knows quite a few curious bugs that had to be tackled by developers. In fact, judging from the story that Media Molecule's CTO Alex Evans shared on his Twitter page this past weekend, many legends are still waiting to be heard. Evans is famous for his part in a demoscene performance of late 1990s and his work on the LittleBigPlanet game series and on Rag Doll Kung Fu.

The case I am referring to in this article took place ten years ago, in 2008. While working on the first part of LittleBigPlanet — an original puzzle platform video game that was to be released exclusively for PlayStation 3 — the company's developers came across a really hard-to-catch bug.

Normally, for a game to get the green light to be released for consoles, it needs to pass a certification process, i.e. meet a set of requirements predefined by the platform owner. The certification may also include more specific requirements, such as the game running smoothly without crashing for 24 hours.

The development of LittleBigPlanet was at its last stage, with just two weeks to final deployment and distribution. Suddenly a tester from the company's QA in Japan reported that the game was consistently crashing when left overnight. Now the release was evidently out of question unless the bug was fixed.