George Georgovassilis writes about technology architecture
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
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
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
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 NAS is perfect because it is simple, safe, modular and extensible and it is cheap because it is … Continue reading Building the perfect, cheap DIY NAS
TL;DR: moving to the public cloud consolidates many small risks into few large ones. A recent GCP cloud outage (https://status.cloud.google.com/incident/cloud-networking/20004) highlights an issue with running more and more parts of the internet on the same infrastructure: as more computing resources consolidate in large cloud providers' data centres, the risk of a significant, global outage of … Continue reading Cloud vs. on-premises is about shaping risk
TL;DR: Prepend "about:reader?url=" to any website URL to force reader view in Firefox I'm in love with Firefox' reader view. It not only removes ads, nag-screens, subscription prompts and other clutter from articles but it's typographical choices often are better than the (well-intended) choices of the author. I also value the consistent look and feel … Continue reading Force-enabling Firefox’ reader view
I'm running a large (>20TB) ext4 file system and noticed that the first substantial write operation after mounting is very slow and involves plenty of drive activity. The reason seems to be some memory structure initialisation as described here: https://linux-ext4.vger.kernel.narkive.com/SUFNE520/ext4-slow-performance-on-first-write-after-mount The workaround is thankfully as simple as running this command in a script after mounting … Continue reading First write operation to large ext4 file system is slow
[updated May 2020] The Acer Nitro 5 is an interesting breed; decent computing power, a mid-range SSD, a large screen with high contrast, a decent and solid keyboard with good haptics at an ok price - but will it run Ubuntu? The Nitro comes with Windows 10 home pre-installed and UEFI secure boot enabled - … Continue reading Ubuntu on the Acer Nitro 5
Standards are a double-edged swordSubbu Allamaraju, CTO Expedia, https://m.subbu.org/lessons-from-2019-5beb64e63bc7 TL;DR: Standardisation reduces the dimensionality of a problem space thus eliminating possibilities for optimisation. Standards reduce the number dimensions of a problem space Consolidation initiatives aim at reducing the number of domains in a problem space in order to make problem handling easier: reduce the number … Continue reading The problem with standardisation
It's been a while since my first (and so far only) reading list (2016) [1], but this decade shall not end without another one. Rules for the 2019 reading list: The content must have been interesting throughout the year; sources with only a few notable publications of an otherwise unremarkable output don't qualifyI overcame my … Continue reading 2019 reading list
