ASRock DeskMini A300M with AMD Ryzen 3400G

7th July 2020

Below are some photographs during assembly of the Asrock A300M with an AMD Ryzen 5 Pro 3400G processor. The Asrock web-site detailing the specs of the A300M: DeskMini A300 Series. Three noticable reviews on the A300M: Anandtech has a very readable review of the A300M: Home> Systems …

Reply to: Neural Network Back-Propagation Revisited with Ordinary Differential Equations

30th June 2020

This article is worth reading: Neural Network Back-Propagation Revisited with Ordinary Differential Equations I replied: Thank you very much for this very informative article providing many links, the Python code, and the results. According the mentioned paper from Owens + Filkin the speedup…

Calling C from Julia

23rd June 2020

Two ways to compute the error function or Bessel function in Julia. 1. Calling C. On UNIX libm provides erf() and j0(). So calling them goes like this: ccall(("erf","libm.so.6"),Float64,(Float64,),0.1) ccall(("j0"),Float64,(Float64,),3) In this case one can omit the…

Gunnar Uldall's Tax Tariff

16th June 2020

Gunnar Uldall wrote a a book with title "Die Steuerwende" in 1996. 1. Proposal. In this book he proposed the following tariff, \(x\) is in DEM. $$ t_u(x) = \begin{cases} 0 & \mbox{if } x\le12000 \\ 0.08\left(x-12000\right) & \mbox{if } 12001\le x\le20000 \\ …

Splitting and anti-merging vCard files

9th June 2020

Sometimes vCard files need to be split into smaller files, or the file needs to be protected against merging in another application. 1. Splitting. Below Perl script splits the input file into as many files as required. Output files are named adr1.vcf, adr2.vcf, etc. You can pass a command line…

Automated Rebooting of Auerswald Communication System

2nd June 2020

The wired telephones in my house are connected to a telephone-system from Auerswald. It's Auerswald COMpact 5020 VoIP. This PBX handles VoIP and ISDN. My children make fun of me that I still use landlines, they just use cell phones. Unfortunately since a couple of months the system no longer is…

Hosting Static Content with netlify.app

27th May 2020

Many people associate netlify.com with its integration to GitHub, GitLab or Bitbucket. But you can just deploy your local files to Netlify as well. Install netlify command via npm install netlify-cli. cd to the directory where you locate your static content. Login to Netlify site via netlify…

Hosting Static Content with now.sh

26th May 2020

now.sh, previously known under zeit.co, which has now rebranded as vercel.com, allows to host static content. There is no PHP, MySQL/MariaDB, Perl, CGI, etc. While surge.sh is super simple to use, in contrast now.sh uses the notion of 'environment', which can be either development, preview, or…

Hosting Static Content with surge.sh

25th May 2020

When you want totally hassle free hosting of static HTML then surge.sh is very attractive. It is easy to set-up and free of charge for most private users. It offers https out of the box from sectigo.com. It does not offer PHP, MySQL/MariaDB, CGI, Perl, etc. Just static HTML with CSS, JavaScript,…

Performance Comparison Pallene vs. Lua 5.1, 5.2, 5.3, 5.4 vs. C

14th May 2020

Installing Pallene is described in the previous post: Installing Pallene Compiler. In this post we test the performance of Pallene versus C, Lua 5.4, and LuaJIT. Furthermore we benchmark different Lua versions starting with Lua 5.1 up to 5.4. 1. Array Access. I checked a similar program as in…

Installing Pallene Compiler

12th May 2020

Pallene is a Lua based language. In contrast to Lua, which is untyped, Pallene is typed. A good paper on Pallene is "Pallene: A companion language for Lua", by Hugo Musso Gualandi, and Roberto Ierusalimschy. From above paper: The compiler itself is quite conventional. After a standard…

Performance Comparison in Computing Exponential Function

5th May 2020

If your computation is dominated by exponential function evaluations, then it makes a significant difference whether you evaluate the exponential function exp() in single precision or in double precision. You can reduce your computing time by roughly 25% when moving from double precision (double)…

youtube-dl HTTP 403 error

1st May 2020

youtube-dl is a set of Python scripts for downloading videos from YouTube, Twitter, Vimeo, and many other sites, see for example the list of supported sites. This is a handy tool if you want to watch videos or listen to music on your smartphone: Download them with youtube-dl and store them on your…

J-Pilot Plugin For SQLite Export

29th April 2020

In SQL Datamodel For J-Pilot I described the SQLite datamodel. I wrote a J-Pilot plugin which can export the below entities and write them to an SQLite database file. The direction is one-way: from J-Pilot to SQLite. Address Datebook Memo To-Do Expense Various categories for above entities Adding…

SQL Datamodel For J-Pilot

27th April 2020

Currently J-Pilot stores its data in binary form which is compatible with the original Palm data format. See Palm File Format Specification. Reading these binary formats is not simple, see for example pdbrd.c. Portion of the internal structure looks something like this: typedef struct { //…

Sharing Terminal Screen Using Tmux

26th March 2020

Sharing your terminal input and output can be done in different ways. kibitz, see Linux commands: expect and kibitz VNC Skype / Teams / Zoom, etc. tmux 1. tmux essentials. tmux (tmux wiki) uses the following vocabulary and hierarchy. server session-group session client window pane The…

J-Pilot Data on Android Phone: Contacts

19th March 2020

Keeping J-Pilot data in sync with Android smartphone is quite a challenge. See my post about Google calendar. Copying contact data from J-Pilot to Android in the past went like this: Export data from J-Pilot in vCard (vcf) format If required, fiddle with this vcf file with some Perl…

ssh and rsync for Android, Termux

12th March 2020

I used SSHelper for some time to rsync my files from my Linux machine to Android phones, see here. I most notably used this for transfering photos. I now use Termux. I prefer Termux over SSHelper as it allows to install new programs within Termux using pkg oder apt-get. Starting Termux looks like…

Surfing the internet with 1 GBit/s

4th March 2020

Adding 30 Cents to my monthly bills bought me Gigabit internet access. I now pay 39.99 EUR per month. Previously I had 100 MBit/s. From user's experience I do not feel any significant difference. Of course, for all my mobile devices, like smartphones, laptop, there is and will be no difference as…

Aggressive Vodafone Router

29th February 2020

Vodafone router does not allow to turn off firewall permanently. It will insist on switching it on after 24 hours. Version of this router in question: Firmware version: 01.02.037.03.12.EURO.SIP Productname: Vodafone Docsis 3.1 This "Made in China" router using…