Nautilus browsing large windows share is slow

When browsing large windows (samba) shares with Ubuntu Nautilus (that's the equivalent of the Windows File Explorer) I observed that shares which include many files and directories (a few hundred) take a few seconds to browse over WiFi, but almost instantly display over a fast LAN. A similar difference in speed is noticeable when searching … Continue reading Nautilus browsing large windows share is slow →

The improved differential amplifier (based on current mirror)

This circuit is an improved version of the differential amplifier built with a current mirror from last year. The previous circuit suffered from a design flaw which I realised only when trying to actually build the circuit with hardware: the collector resistors are way too small (actually 0Ω) for a sensitive circuit. The current going … Continue reading The improved differential amplifier (based on current mirror) →

Increasing Android mobile network stability

My habitation/network carrier/phone combination-situation results sometimes in slow or no internet on my Android phone. I'll talk about a hidden setting which, when properly configured, can increase network stability on an Android phone. Please read the entire post before trying anything, there are severe caveats. Understanding the problem I've had Android phones since 2.2 and … Continue reading Increasing Android mobile network stability →

Constant disk access with ext4 caused by kmmp

I don't know how I never noticed this, but the mechanical hard disks in the perfect NAS emit a clicking noise at regular intervals that never stops. The NAS runs Ubuntu 18.04 server, an md software RAID 6 with dmcrypt on top, formatted with ext4. Disk I/O is way too low to show anything useful … Continue reading Constant disk access with ext4 caused by kmmp →

Jugaad takes agile to the extreme

Introduction Jugaad is an attitude towards delivery which originated in India and consists of three simple tenets: Humility: use whatever works without prejudiceOpenness: keep your options openFrugality: small expenses keep regrets small Jugaad is agility taken to the extreme and most suitable for projects with a high degree of change, risk and uncertainty. Nothing demonstrates … Continue reading Jugaad takes agile to the extreme →

Voltage comparator with oscillator

Readers of this blog know that I'm fascinated by everything around switched amplifiers. The core piece of every switched amplifier is a voltage comparator. Today I'll write about a comparator design based on an oscillator. The simplest voltage comparator compares two input voltages A and B and outputs a high voltage is A > B … Continue reading Voltage comparator with oscillator →

The improbable fallacy

TL;DR: probabilities are so darn counter-intuitive, that one should not rely on "99% accuracies". Imagine you seek out your doctor because of a chronic case of hypochondria. All tests covered by your insurance turn out negative and your doctor tells you to man up and live with it. Being a House M.D. fan you refuse … Continue reading The improbable fallacy →

Function pointers in Java

Overview The last post about reactive programming introduced an experimental library which, among other things, implements method references (aka function pointers) for Java. If Java allowed for such a syntax, I could imagine a succinct example: class TestClass{ int add(int a, int b){ return a + b; } public void test(){ FunctionPointer fp = TestClass.add; … Continue reading Function pointers in Java →

Building the perfect, cheap DIY NAS

This post was extensively discussed on Hacker News. I've been running for a decade a self-built NAS at home, so I thought I'd write down my experience so that others might gloat over my many failures and gasp in awe at my few triumphs. The HP Proliant microsever gen8 is affordable, compact and runs on … Continue reading Building the perfect, cheap DIY NAS →