Conny and I went walking this afternoon. But
before we started on our walking trip, we first visited a marke stone and looked for a triangulation point. At 13:36, we visited
the marke stone Steenen paal bij de Nijkerksdijk. It actually is not a
marke stone, because the border of the two marke Haaksbergen en Honesch
and Langelo runs to the East of it, but a stone that marked the border
between the border of the provinces Overijssel and Gelderland as it was established in 1775. At 13:42, we searched for
triangulation point 340331. On the side of the road we found a sign to locate
the triangulation point stating the number 340 (on top) and 331 (on the bottom)
with the number 2,7 in the middle. The 2,7 seems to indicate the distance to
the actual triangulation point. It was not clear in which direction we should
search. At home, I concluded from some pictures, which I only noticed then,
that the point was close to the road and just below the surface. We probably
have stood on top of it. The first part of our walking trip was along a brook
called Koffiegoot (coffee gutter), which probably was called like
this because of its brown colour. At about 14:10, we found the marke stone
Hellekampspaal, which is rather large, about 170 cm tall and measuring
48 by 48 cm wide, and also served to mark the border between the two provinces
and was placed there after a long running border conflict between 1611 and
Using Brainfuck for bootstrap
Yesterday, I came along a mentioning of live-bootstrap on Hacker News,
which also lead me to the Bootstrappable
builds website. I also found the Bootstrappable builds article on LWN.net. This morning, I spend some time
digging into it, trying to understand the live-bootstrap GitHub reposity. I
actually ended up looking at the oriansj/stage0 GitHub reposity in particular the hex0_x86.hex0. I am a little surprised that it is opening files as
specified on the command line, instead of simply reading from the standard
input and writing to standard output. According to bootstrap-seeds README.md file, one way to process the hex0_x86.hex0 file
is using the sed UNIX utility
to remove the comments and the xxd UNIX utility to change the hexadecimal pairs to raw bytes.
However, the README.md also states (in capitals): "NEVER TRUST ANYTHING IN
HERE". Because, yes, you have to trust the implementation of sed and xxd.
I wondered whether Brainfuck could be of any help
in this area or as a basis for a bootstrap environment, because it is a very
simple language for which a large number of interpreters in many different
languages have been implemented. I even spend some time working on a C program
to generate Brainfuck code as I did before for the Brainfuck interpreter written in Brainfuck.
Addition May 6: In a comment on Hacker News, Kragen
Javier Sitaker writes that he did consider
Brainfuck for a Universal virtual computer (UVC) and
bootstrapping a compiler from a tiny compiler using Brainfuck.
Yesterday morning, the temperature dropped as low
as -1.3° Celsius (and -5.7° Celsius at ground) level at Twenthe
Airport, while today it went up to 27.0° in the afternoon and remained
above the 20° for the rest of the day, while in the past weeks the
temperature but barely reachted 15°. This might also explain why today,
there were still some flowers on our magnolia. In
the afternoon, Conny and I went walking in a
forrest just North of the area where we walked last
Sunday. On the way there, we stopped near triangulation point 340331 and
around 12:52 we succeeded in locating it just below the surface. After having
it photographed we covered it up again. When we rested on a bench during our
walk, we say a bee hover over the ground and than started to dig at some spot.
After about a minute it had disappeared under the ground not leaving any
visible hole. At home we created a small kitchen garden from the germinating
seeds that Conny got from the supermarket Albert Heijn as MoestuinMaatjes.
BrainFuck program for stage0 seeds
In the past week, I created a BrainFuck generator, which generates BrainFuck from a relatively simple programming
language, for the purpose of writing a BrainFuck program that could replace
the seeds for the
oriansj/stage0 github repository. This BrainFuck basically implements the
sed 's/[;#].*$//g' $input_file | xxd -r -p > $output_file
mentioned in the README.md. I extended my BrainFuck interpreter /
code generator with the -eof0 command line flag for returning
0 when end of the input has been reached. I used the following two command
to test it:
./bf -eof0 hex0.bf <~/git/bootstrap-seeds/POSIX/x86/hex0_x86.hex0 >hex0-seed
cmp -l hex0-seed ~/git/bootstrap-seeds/POSIX/x86/hex0-seed
Where hex0.bf contains the BrainFuck program generated by the BrainFuck generator page. I know that it does really solve the basic
problem of generating a binary without using a binary that one cannot trust
100%, but it does give an alternative for the sed and xxd commands or using.
Even using a BrainFuck interpreter written in BrainFuck of a BrainFuck to
x86 executable compiler
written in BrainFuck cannot solve the fundamental trust problem.
This evening, I noticed that some of my files of my website contained other
line ending than the windows carriage-return line-feed combination. I wrote
a small program to fix these. With no command
line switches it just reports the number of errors in each file that contains
incorrect line endings. The command line switch -l will also report
the lines and the combination with which that line ends. The command line
switch -f will fix all files mentioned on the command line. This does
require a directory org to be present, to which the original files
will be copied.
After having visited my mother, Conny and I
Kootwijk. We walked around Building A and when we saw dark clouds approach,
we decided to go home and not search for a possible border pole of the
municipality of Apeldoorn.
In the past weeks, I have been working at the
HEMA puzzle that I started looking at on October 27, 2017. Some weeks ago, I noticed that one solution for the
puzzle that Conny had found could be
changed into a number very similar solutions by pair wise rearranging of
pieces. This raised the question about what would be the shortest arrangement
of the 89 solutions, such that consecutive solutions had the largest number of
pieces in common. I developed a program for
finding it. The shortest sequences which was found by the program is:
The diagram below shows the similarity between solutions in the order the
solutions are shown below. The redness indicates the extend that pieces that
are not exactly at the same position and orientation, do overlap.
It seems you can conclude from the diagram that there are only five solutions
that cannot be changed in another solution by swapping two pieces. There also
seems to be three large groups of solutions that have three groups of two
pieces that can be swapped.
Some weeks ago, The Royal Netherlands Academy of Arts and Sciences awarded Jaap van
Dissel, the Director of the Centre for Infectious Disease Control at the
National Institute for Public Health and the Environment (CIb-RIVM) the
Academy Medal for the way in which he has approached his role as scientific
advisor to the Minister of Health, Welfare and Sport and the Dutch Government's
crisis team during the COVID-19 pandemic. Recently, The Independent Panel
issued their Main
Report in which they concluded that the COVID-19 pandemic could have been far less serious, In the report it says:
On 30 January 2020, it should have been clear to all countries from the
declaration of the PHEIC that COVID-19 represented a serious threat. China had
reported upwards of 20 000 confirmed or suspected cases and 170 deaths. The
number of countries to which the virus had spread and where local transmission
was occurring was growing by the day. Even so, only a minority of countries set
in motion comprehensive and coordinated COVID-19 protection and response
measures — a handful even before seeing a confirmed case, and the
remainder once cases had arrived. My impression is that the CIb-RIVM did
not take the PHEIC of the WHO very serious. Even when several weeks later the
first cases were reported in the Netherlands, it felt like they were playing it
down, afraid to cause panic. It seems that for the Academy the COVID-19
pandemic only started at the end of March 2020 and did they did not take into
accound his role in the slow responds of the Dutch Government to the January 30
declaration of the WHO.
At 17:27:18, I bought the book Theo van Doesburg, schilder en architect
written by Evert van Straten in Dutch and published by SDU in 1988,
ISBN:901205902X, from bookshop Broekhuis for
This morning, Conny and I went walking (again)
in the South of the Lankheet estate. On our route there, we stopped to have a
look at the Morspaa, marke stone with
number 48.50-02. At 9:27, we visited the stone, which in 1712 was placed at a
location about 17.5 meter to the southeast. At some point it disappeared
underground. On September 4, 2003, it was dug up and placed at its current
location. At 10:05, we found the Mallumseveenpaal, which is about 1.80
meter high and measures about 45 by 45 cm. In this regard, it is very similar
to the Hellekampspaal we found on May 2. Not so
strange, because it too is placed at the border of the provinces
Gelderland. It is also
at the border of the marke Langelo (to the north) and Mallum (to the south).
In the afternoon, Conny and I went to charity shop
Het Goed to donate some goods. We also went in to have a look at the books
and other things. I ended up buying four books and a jigsaw puzzle. At 15:39,
I bought the following books:
- Bientôt l'été written by
Frédérique Bertrand in French and published by
Esperluète in 2007,
ISBN:9782930223858, for € 1.75.
- Chico Montilla written in English and Spanish and published by
Sammer Gallery in 2003 for € 1.75.
- Pi De Bruijn: Engagement + Stedenbouw edited by Wilja Jurg and
Marianna Lahr, written in Dutch, and published by Gemeente Enschede in
2008, ISBN:9789080601291, for € 2.00.
- Personal Structures: La Biennale Di Venezia 2011 written by Karlyn
De Jongh, Sarah Gold, and Peter Lodermeyer, written in English, and
published by Global Art Affairs Publishing in July 2011,
ISBN:9783941763098, for € 2.50.
TkkrLab: Space 6
TkkrLab is moving to a new space: Space 6,
which is at Marssteden 98. Anything mailed to 'NL 7547TD 14' should arrive. This
weekend, I helped a few hours moving some things, mainly Samla storage boxes.
In the past week, I continued working on the HEMA
puzzle, which resulted in the animation/tool shown below. The large square
is basically the same as the one shown before, except that green is used to
show that there exists a solution between the two solutions that has less
changes with both solutions, meaning that difference is implied by other
transitions. Bright green is used to indicate that the changes do not overlap,
meaning that there at least two intermediate solution and that the transitions
are commutative. On the right it shows the colours of the pieces that change
place between two consecutive solutions. The more colours are shown, the more
pieces change place. On the sides of the large square, black lines select which
solutions are selected. On the bottom it shows these solutions and the one
before and after it, when applicable. The following keys can be used (after
clicking in the animation) to manipulate the display:
The text area below the animation shows on the first line the number of
coloured squares on the right. This can be seen as a measure of the quality of
the ordering of the solutions. The remaining of the lines are used to show the
current ordering of the solutions.
- d: move the select down
- u: move the select up
- l: make the number of selected solutions larger
- s: make the number of selected solutions smaller
- D: move the selected solutions down (and the one below it above
- U: move the selected solutions up (and the one above it below it)
- M: mirror the selected solutions (at least two need to be selected)
- i: toggle the green colour for implied solutions
- e: toggle the green colour for commuting transistions
- p: toggle the red colouring
In the morning, Conny and I went walking in
the Lankheet estate. We walked through the water park and ended at the Kidney
Pools, an art work by Jim
Buchanan. The water park is created in an area where there used to be
water-meadow and now
is made into a constructed wetland (12 hectares of reed bedds) to purify water from
the Buursebeek to be
used in the forests of the estate. We entered the Kidney Pools through the
round tunnel which is visible in the picture below. It somehow reminded me of
the exit of the Eder Kemo age of Uru: Ages Beyond
This afternoon, I received a small PCB with a MCP4728 IC on it, which I bought
online. The MCP4728 is a 12-bits, quad digital-to-analog converter. I am thinking
about using it in combination with a small microprocessor to create a control
voltage generator for a modular synthesizer. I could use the
Adafruit MCP4728 library.
GOGBOT Café - Welcome to the post-truth paradise!
I watched GOGBOT Café -
Welcome to the post-truth
paradise! (It could not pay my full attention to this.) It had the
Because I stopped watching the live stream, I do not know if any discussions
were held afterwards.
- Nolen Gertz talked about social media. He wrote the book
Nihilism. If I am
not mistaken, his conclusion is that social media are what we want them to
- Sabine Niederer started to talkes about climate fiction (Cli-fy). I
had a hard time following her talk. It felt she only talked about all the
project she did, without drawing any conclusion about those.
- Jasper van den Bovenkamp is a journalist, who talked about truth has
become personal and lying politicians are the norm. He talked with long and
complex sentences in a rather monotone manner, suggesting that he was
reading or reciting a text he carefully prepared.
- Bullethead: a Post-Real Dictator from an uncertain era will bring the
discussion to full completion. I could not make much sense of this
and stopped watching it after a few minutes.
I ordered some items from TinyTronics including a multimeter, a JYE Tech DSO150 (a simple oscilloscoop), three Nano V3.0 compatible boards, and two FM62429 ICs. The FM62429 IC is a two
channel digital volume control. I am thinking to build an ADSR envelop generator and VCA from a Nano and a FM62429.
At 11:04:51, I bought the book Het markeboek van de Eschmarke edited by
Frans J. M. Agterbosch and H.F. Mensink, written in Dutch and published by
Stichting Genealogische Werkgroep Enschede in 2010,
ISBN:9789074983273, from bookshop Broekhuis
for € 27.50.
I got the book Wat wij zagen written by Hanna Marleen Bervoets in Dutch
and published by Stichting Collectieve Propaganda van het Nederlandse Boek in
2018, ISBN:9789059654334, for free as part of the Boekenweek.
This months interesting links
| April 2021
| June 2020