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Dutch / Nederlands

Diary, August 2016

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Tuesday, August 2, 2016

Antique hardware

I brought some antique hardware to TkkrLab. When I showed the motherboard of annabel, someone immediately noticed that the battery had gone bad and had erode some part of the motherboard. After the battery was removed and the motherboard had been cleaned it was powered up. It give some beep, but nothing appeared on the screen. We tried it again with some card (IDE controller, I believe) and again it gave some beep. But at some point we heard some strange buzzing sound that seemed to originate from the power supply. We switched it of. I saw some led light up shortly. When we switched it on, the sound was gone, and the power supply worked normal. We checked to voltages and they were fine. But how we tried to boot the mother board, it did not beep again. A boot monitor is needed to debug it further.

Next, I showed my Acorn Atom. Although the others were impressed by the DIY power supply, they were afraid the large elektrolyt condensator could explode or at least fill the room with smoke. But there was an alternative power supply available. It turned out that the Acorn Atom only drew about 700mA, so every USB power supply would be enough. There was also no television available, but with some soldering it was possible to get a video signal and put that into a monitor with video input. And it work, as can be seen on the picture. It left it at TkkrLab. It is one of the oldest, if not the oldest piece of hardware at the hacker space. Maybe we can find some way to quickly load some games.

I also brought a Laser color computer 310, but we did not look at because I had to go home early.

Wednesday, August 3, 2016

Institute for art history

Today, Peter Struycken and I visited the Netherlands Institute for Art History, for a second time. (July 23, 2015 was the first time.) We continued working on the notes that Carel Blotkamp compiled for a catalogue of works. After we finished it, we looked at some binders with negatives and contact prints of art works. At his home, Peter showed me the new works that he has made for the exhibition Dutch concert, P. Struycken en Carel Blotkamp that will open on September 3. I was quite impressed by the new works.

Thursday, August 4, 2016

20,000 days

Today, it is 20,000 days ago that I was born. I decided to celebrate this special day by treat my colleagues on (small) cake and give a party for my family and some friends. Not all my family could attend because of other responsabilities. Five friends came. I received some cards and small presents. If you want to know when you will be 20,000 days old, you can use: 20,000 Days on Earth. Last Tuesday, I received the DVB-T+FM+DAB stick that I had ordered on July 22. Today, I installed some software to receive ADS-B signals, which are transmitted by aircraft. It did work with the small antenna that was included with the DVB-T receiver stick. Of course, I had to show it to everyone visiting.

Tuesday, August 9, 2016


At 11:45, I bought the book Living inside the grid edited by Dan Cameron written in English published by New Museum of Contemporary Art in 2003, ISBN:9780915557868, from charity shop Het Goed for € 2.95.

Parallel parser

Last week, I got a good idea how to implement a data structure for implementing parallel parsing, and in the past days I made a prototype implementation before intergrating it in IParse and, possibly, later intergrate it with MySample editor. This prototype implementation uses a very simple mechanism to implement parsing rules. Terminals are simple character.

(Improved implementation)

Thursday, August 11, 2016

Temperature at zero

Last night the temperature at ground level (10cm/4inch above, to be exact) at the official weather station at Enschede Airport Twente dropped to zero. It is only the third time that a temperature to or below zero is on record in August in the Netherlands and the second time in Twente. It never dropped to (or below) zero between July 20 and August 21.

Monday, August 15, 2016

Surreal number calculator

I worked on an online calculator for Surreal numbers using JavaScript. I did this a preparation of a talk a plan to give with the title: "From Nim to Go to Surreal Numbers".

Tuesday, August 16, 2016


At 13:20, I bought the following three books, each for € 1.95, from charity shop Het Goed:


I am planning to also include something about the game Domineering in my talk "From Nim to Go to Surreal Numbers". While at TkkrLab, I decided to implement the game on the IJduino. I got the idea to use a single potentiometer as the interface. Players have to take turn placing a domino stone. By turning the potentiometer a player can move through all possible locations. The selected location can be indicated by a pair of blinking LED's. After the player has stopped turning the potentiometer, the blinking frequency will get slower and come to a halt. This gives the players some time to change their minds. Before the players turns the potentiometer, nothing happens. I first had to find a potentiometer. Another member was so friendly to donate a 10KΩ potentiometer from an abandoned project. I had to do little rewiring to get the potentiometer connected with all the other things already connected to it. I did find a nice solution. First wrote a progam to check if I could read a value from the potentiometer. Which was rather easy. Next I continued to work on the program, which went without much trouble. I realized that the game took rather long when using all eight by eight LED's of the display. I decided to reduce it to five by five. But at the start of the game it is not clear what are all available positions. I decided to invert the lights, making it the goal of the game to make all LED's go of, which of course, with an odd number of LED's is impossible. It turned out to be a nice way of signaling the winner, as this is the player that has the last pair of LED's of her direction blinking. I did notice that the value returned from the potentiometer at some positions is not really stable if you do not turn, but I have not come up with a way to fix this. The resulting program is: domineering.ino. I also spend some time intergrating all my previous programs in a single program, using the Bluetooth connection to selecting the functioning, removing the need to reprogram the IJduino all the time. I did not finish this.

Also had a look at the emfcamp badge: a microcontroller with small display runing micro phython. I also talked with some other member about the Acorn Atom and the SD/MMC card interface designed by Charlie Robson, which makes use of pic16f874p controller. We agreed that I would order a pic16f874p. But at home, I discovered that it seems that this controller is no longer on sale. I also studied the various descriptions of the SD/MCC card interface, realizing that they are quite old and I got the impression that there are are some holes in the description. I wonder if it is possible to replace the PIC microcontroller by an ATmega168 microcontroller. I presume that the communication between the Acorn Atom and the pic16f874p makes use of a relatively low speed serial connection and that it would not be so difficult to access an SD card. I downloaded two ROM images to be placed inside the Acorn Atom for further analyses. This is going to be an interesting project.

Wednesday, August 17, 2016


Yesterday, I bought three AKI finals catalogues. There were some more of them, but they were already marked on a short list that I always me carry with me of catalogues that I already own. Today, I noticed that it contained an error with respect to 1992. I do own a small book from 1992, but it is not the finals catalogue. I vaguely remembered having seen the yesterday, so, I went back this afternoon to charity shop Het Goed, and found it. At 17:26, I bought the AKI Akademie voor Beeldende Kunst eindexamencatalogus 1992 edited by Bas Könning, Gerhard van Dragt, Marijke Harmens, and Sipke Huismans written in Dutch published by AKI Akademie voor Beeldende Kunst in 1992, ISBN:9789073025042, for € 1.95.

Thursday, August 18, 2016

Preparing for talk

This afternoon, I worked on preparing my talk "From Nim to Go to Surreal Numbers". I prefer to give a talk in front of a black board and just write down and draw things as I go along. I do not like preparing slides, and especially not in PowerPoint. I thought about using strut, but after having wrestled with for an hour and discovering its short comings, I decided to simply create a webpage with HTML and JavaScript. During the presentation I will simply scroll through the (zoomed in) page. It also allowes me to start a short video clip and intergrate the Surreal number calculator, which I wrote last Monday.

Friday, August 19, 2016

Disassembling ROM's

In the past days, I worked on disassembling two ROM's for the Acorn Atom that can be found on AtoMMC2: An SD/MMC card interface. For this purpose I wrote a program (based on source from the Acorn Atom emulator I worked on long ago) that generates quasi C code for easy readability (at least for me). I made use of a handy online 6502 disassembler, Acorn Atom memory map and disassembly of the Acorn OS ROM. I appended the output of the program to this program listing (which I might update in the future).

Saturday, August 20, 2016


In the afternoon, I arrived at Zomergo, a rather relaxed Go retreat. I was of the first to arrive. The first tournament round was held in the afternoon. I won by resignation. On the right top the state of the board at the end of the game. Dinner was quite late, as usual. Afterwards some girls wanted to program the game snake on the IJduino. One of them had some experience with programming and we succeeded in implementing it using the potentiometer, which adds an additional constraint, because you cannot turn left (or right) too often in a row, because you cannot turn the potentiometer in one direction indefinitly. (The snake.ino program.)

Sunday, August 21, 2016

Zomergo: Second day

In the morning, I played against a young woman, who just in the past year learned playing Go, but appeared stronger than me. It seems she is much better at reading than I, after I made a daring move (one that should not work) she was able to capture a number of stones, after which defeat was eminent. In the afternoon, I helped with preparing dinner for about four hours gutting vegitables.

Monday, August 22, 2016

Zomergo: Third day

In the morning, I played against man and and won the game with a slim margin. In the afternoon, I gave my talk about Nim, Go, and surreal numbers to about eight people.

Tuesday, August 23, 2016

Zomergo: fourth day

In the morning, I played against woman and and won the game with nine and half points. I also worked on perfecting a short script for MySample to extract the state of a Go board from a 190 by 190 pixel image. The output of the script is used to display the Go board position at the end of my games.

Wednesday, August 24, 2016

Zomergo: Fifth day

In the morning, I played against young man and and lost the game with nine and half points. From the start of the game, I felt uncomfortable about it. Half way, I thought about resigning, but still continues. My opponent suggested that I could still invade some corner. Because I had not seen this myself, I did not feel comfortable trying it. He felt that I regain some of my loss towards the end of the game.

In the afternoon, I helped with preparing the dinner. In the evening, there was a rather clear sky and with relatively less light polution, one could see many stars. We walked to a nearby field where it was darker. We could see (part of) the milky way.

Thursday, August 25, 2016

Zomergo: Last day

In the morning, I played against a young girl. I had to give her nine stones ahead. At first it seemed that she was going to make a lot of territorium in the center, but soon, I was sure of victory, but I did not want her to lose big, so I made many 'stupid' moves, and allowed her to close some place where I could invade. Nevertheless, she still lost with about seventy points. Afterwards, we played another 'teaching' game on a thirteen by thirteen with five stones ahead, and with my suggestions, she easily won that game.

The Green Cathedral

In the afternoon, I visited The Green Cathedral, a landscape artwork by Marinus Boezem. I walked around and through it, and took some pictures. The GPS-track of how I traveled today in KML file for Google Earth or in Google Maps

Sunday, August 28, 2016

Parallel parser improved

Since I wrote about a parallel parser on 9th, I have been working on fixing problems with memory deallocation. I soon realized that not all parse state representing objects were deleted, as soon as they no longer could be reached, and that actually most of them were not deleted at all. Although this does not show in the output of the first published implementation, I do find it an essential requirement, especially when the purpose of the algorithm is to be used to parse lines in an editor over and over again, causing the memory footprint to grow with every keystroke. In the process the code has been changed considerable. The current version also contains a lot of tracing code, because it took me quite a lot of time to figure out what was going wrong and how to fix it. The idea is to integrate this prototype with the existing IParse implementation.

Tuesday, August 30, 2016

TkkrLab fun

Fun things this evening at TkkrLab

Tried to install Android development environment.

Wednesday, August 31, 2016

Impatiens glandulifera

I already had suspected that one of the seeds of an impatiens glandulifera that I had put in the garden two years ago, some time after I found the plant on August 18, had started to grow, but now I know for sure, when I saw that it had produced a flower. The plant did not look very healhty and immediately I gave it some water. Here on the top right a picture. This is know to be a one year plant and I was a little surprised to see it, because it is two years ago that I planted the seeds and did not know that it could survive so long. I do not know if it will produce seeds, because I guess that the flower needs to be pollinated and I am not aware of other plants in the neighbourhood.

This months interesting links

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