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Quorten Blog 1

First blog for all Quorten's blog-like writings

Things I learned about new Trisquel and Raspberry Pi firmware flashing

quorten

2018-09-19

Categories: misc   raspberry-pi  
Tags: misc   raspberry-pi  

Some interesting things I learned from the Trisquel forum, or from upgrading from Trisquel 7 to Trisquel 8.

Some nifty tricks if you want to install KDE on Trisquel 8.

sudo apt install plasma-desktop
sudo apt install triskel

20180918/https://trisquel.info/en/forum/why-mate
20180918/https://trisquel.info/en/forum/why-mate-instead-kde

Beware that Trisquel 8 is bigger than Trisquel 7… but there are some things you can do about that.

20180918/https://trisquel.info/en/forum/why-trisquel-8-so-much-bigger-trisquel-7

For example, if you do a dist-upgrade, there will be old GNOME packages left behind from Trisquel 7. You can purge those packages as follows:

sudo apt purge gnome-system-monitor gnome-screenshot baobab \
  file-roller gnome-search-tool gnome-calculator gcalctool gedit \
  gedit-common gnome-dictionary gthumb gthumb-data

sudo apt purge libgtkmm-3.0-1v5 libgtksourceview-3.0-1 \
  libgtksourceview-3.0-common gir1.2-gtksource-3.0 libgdict-1.0-9 \
  libgdict-common

Read on →

Interesting idea for a new icon to represent myself

quorten

2018-09-18

Categories: random  
Tags: random  

Amidst a sea awash of Amazon, Facebook, YouTube, Netflix, Hulu, Google G-suite, Apple iPhone, Android… there is but one Raspberry Pi icon, and very tiny at that. Yes, now we’re looking at the really zoomed out picture, beyond the formal partitions drawn. It’s about the big picture, not about me.

Inside the Raspberry Pi is the even tinier partitions icon, with the even tinier QR barcode. And the spatial size of the icons must be drawn to scale of the size of the markets.

Or how about this. One icon of the biggest, and say “Drawn to scale.” That works well for a small icon. Or, now this is interesting. An Earth with an Amazon icon over one of the continents. Okay, let’s go with colors to keep it simple. You’ll get the idea better, and go with a flat map.

UPDATE: So, here the icon is.

More info on DSLR anti-static sensor brush cleaning

quorten

2018-09-18

Categories: pentax-k-1-camera  
Tags: pentax-k-1-camera  

So now I’m wondering. If you get a sensor cleaning anti-static brush, is it okay to charge it up with a blower brush?

20180918/DuckDuckGo can you use a blower brush to charge anti-static brush

Well, now this has been consistently interesting. Are you wondering about the dust cleaning problem for DSLR cameras? Many decades back, most of the dust problems and dust cleaning methods/techniques have been discussed and mastered with vinyl records. Of course, because vinyl records are used over and over again and again, so dust will tend to get stuck to them that needs to be removed for reuse. Of course, make sure you don’t try to use the exact same instruments used for cleaning vinyls to clean a DSLR camera sensor, or else you will get big troubles.

In regard to cleaning film negatives, I guess you can say the same, that the best cleaning methods for film negatives are those that are best for cleaning a DSLR camera sensor.

Read on →

Null pointers

quorten

2018-09-18

Categories: unlipic   tour-de-force  
Tags: unlipic   tour-de-force  

About null pointers. Yep, we’ve heard that the one of the main people involved in popularizing null pointers regretted it. Why?

20180918/https://en.wikipedia.org/wiki/Null_pointer

Well, the goal here was to have the compiler do all type safety checks at compile-time to guarantee that the complex data types are absolutely safe. No runtime type checking necessary. But what if you have a function that can fail at runtime and can’t really return a valid object? Well, as I understand it, the story must work like this. You use two separate variables, one that is always the correct, static object type, and another to indicate if failure has happened. Then it is up to the program to check for failure at runtime. If it doesn’t, the program will pass around and attempt to process a dummy object of the correct type, which should fail at runtime, maybe even cause a crash if the complex type code is poorly written.

So, the point that I wanted to put forward is this. There is no easy way to do “safe typing” with complex types. By definition, the data and behavior must be more complex, and that requires more logic, which means there will be more points of failure.

Interesting software for testing Ansible roles, Docker-in-Docker

quorten

2018-09-18

Categories: ansible  
Tags: ansible  

Interesting software for testing Ansible roles, even within Docker-in-Docker.

20180917/https://molecule.readthedocs.io/en/latest/

An interesting Ansible blog post, Ansible in large scale deployments. The trick to using Ansible in large-scale deployments? Ansible is only meant to be used to automate functions that you want to perform across a cluster all at once. Typically in very large scale deployments, you don’t want to change everything all at once. Rather, you want to upgrade in shards. It is these individual shards that you would run Ansible on to manage them with, one at a time.

20180926/https://www.ansible.com/blog/large-scale-deployments-using-ansible

This Ansible script is useful for removing deprecated Ansible syntax with tests as filters to proper jinja2 test syntax. The old syntax has been removed in Ansible 2.9.

20180927/https://raw.githubusercontent.com/ansible/ansible/devel/hacking/fix_test_syntax.py

Everything I need to know about DVD video encoding and HTML 5 video migration

quorten

2018-09-16

Categories: media-prog  
Tags: media-prog  

What you… okay, what I need to know about DVD video encoding. First of all, some important background information. Smartphones surged in growth in the year 2010 and have reached a mature user base measuring in the billions by the year 2015. All modern smartphones are equipped with video cameras that are capable of recording both photos and videos. The video encoding system output is compressed with H.264 AVC, making it perfectly suited for upload to social media video sharing sites and playback from modern HTML 5 browsers without any video transcoding. In fact, the only format conversion that may ever be needed is to repackage the video codec stream into a different container format. Beyond that, all other format conversions are mainly provided as a convenience, not a necessity.

Now, let us for a moment take a step backwards from the modern era. What happened before the times of the year 2010? Before the year 2010, we were living in the dark ages of video recording and playback. To be honest, there were no clear standards that emerged that were suitable for all uses of video recording.

Read on →

Choose lead-acid batteries for home router battery backup, in Minnesota

2018-09-15

Categories: battery-backup  
Tags: battery-backup  

So, the decision has been made that a lead-acid battery is ideal for me to use for a battery backup system for my network equipment. It’s rechargeable, it works well when stored at 100% charge, it doesn’t require require exercising to low charges like lithium-ion batteries, it doesn’t require replacement after power outages like alkaline non-rechargeable batteries, and it lasts a decent amount of time before replacement, at least a few years, 5 years, or maybe even longer.

So, now we’re looking for options that supply DC 12 V directly without wasting power at an inverter. Here’s one good website that I found.

20180914/https://www.powerstream.com/SLA.htm
20180914/https://www.powerstream.com/lead-acid-charger-Catalog.htm
20180914/https://www.powerstream.com/12V-backup.htm

  • Footnote: In Minnesota, we don’t have power outages very often, so if lithium-ion batteries were charged from line AC power, they would require artificial, manual maintenance exercise to stay healthy. Conversely, connecting them to solar power would provide daily exercise, but that would mean they might last for less than 5 years, hence more maintenance than lead-acid batteries connected to line AC power.

Still looking to buy a Li-Fi transceiver, and reflections on Li-Fi

quorten

2018-09-14

Categories: home-network   reiterate  
Tags: home-network   reiterate  

I’m still determined to buy a Li-Fi transceiver, not just read about how it will revolutionize the future. So, keep searching.

20180914/DuckDuckGo buy li-fi transceiver

Now, now, all signs seem to point to building your own Li-Fi transceiver if you want Li-Fi today. Yeah, that is totally an option, it’s just that you won’t get competitive bandwidth and speed if you build your own.

20180914/https://www.alibaba.com/showroom/lifi.html
20180914/https://www.homemade-circuits.com/lifi-internet-transmitter-circuit/
20180914/DuckDuckGo build your own li-fi transceiver

Now this Instructable is really botched. Totally just a proof-of-concept if you need to put the light through a paper tube.

20180914/https://www.instructables.com/id/DIY-Li-Fi-Using-Arduino-Uno/

Read on →

As of 2018, better hardware for Linux than Windows

quorten

2018-09-13

Categories: tour-de-force   chat  
Tags: tour-de-force   chat  

Chat notes!

A Linux SOE would definitely allow for more hardware choices too, as of 2018. (Surprisingly that was even somewhat true 15 years ago, although the mainstream pundits didn’t fully realize it.) Although, an important point in hand is that even our current Windows SOEs don’t cover the full range of available Windows hardware.