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I write, therefore I am

With this variation on a famous statement by the philosopher Descartes, I would like to express that the act of writing about what happens in my life is important to me.

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).

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.

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.

Tuesday, August 16, 2016


At 13:20, I bought the following three books, each for € 1.95, from charity shop Het Goed:
  • Eindexamencatalogus 1995 written by Kees Schippers and Sipke Huismans, edited by Bas Könning, Boris Veldhuyzen van Zantern, Marijke Harmens, Coen Scheen, and Sipke Huisman written in Dutch published by AKI Akademie voor beeldende kunst in 1995, ISBN:9789075522020.
  • AKI eindexamen catalogus 2001: wat is de filosofie achter je werk? written by Boris Veldhuijzen van Zanten, Nelleke Zandwijk, Sipke Huisman, and Maarten Binnendijk written in Dutch and English published by AKI in 2001, ISBN:9789075522181.
  • AKI 2003 edited by Peter Sonderen and Wouter Hooijmans written in Dutch and English published by AKI Akademie voor Beeldende Kunst in June 2003, ISBN:9789075522211.


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.

Monday, August 15, 2016

Surreal numbers 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".

Sunday, August 14, 2016


  • CHIP 8 by secondsun: A TDD Chip-8 implementation designed to teach how to write an "emulator" from scratch.

Saturday, August 13, 2016


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.

Wednesday, August 10, 2016


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.


  • strut for presentations

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.

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.

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.

Sunday, July 31, 2016


Saturday, July 30, 2016


I received the book On Numbers and Games written by John Horton Conway in English published by CRC Press in 2000, ISBN:9781568811277, which I ordered on last Wednesday from BOL.com for € 61.02. It is a different book than I had in mind, but nevertheless, I am quite happy with it. I am going to use it as preparation for a talk with the title: "From Nim to Go to Surreal Numbers" that I plan to give on ZomerGo.


Tuesday, July 26, 2016

News ticker

This evening at TkkrLab, I decided to further experiment with the Bluetooth communication. For this reason, I took the code of the IJduino cp437 program and first modified it to make it display the text to move from right to left at a fixed rate. Next I started experimenting with a method to read a new text from the serial interface, which is connected to a Bluetooth HC-06 module. The readBytesUntil method on Serial seemed the way to go, where the first paramter is given the value 10 for the newline character. The working program: newsticker.ino. Using the Arduino bluetooth app, I could enter a new text in the IJduino news ticker program. Next I wanted to also be to send a text from my netbook. Last week, I already tried to enable Bluetooth on my netbook. Now, I tried to use a Bluetooth stick that I bought a long time ago. I opened it up (just by removing a piece of tape holding it together, because it had already fell apart), and found the number BC04, which seems to indicate it is a Taiyo Yuden® Bluetooth BC04 External Bluetooth USB device. I inserted it and experimented with some bluetoothctl commands. I managed to get a /dev/rfcomm0 device and wrote a small C++ program to write the text Hallo Frans to the given device, which when executed did cause the text to be displayed on my IJduino. (I could also have used echo 'Hallo Frans' >/dev/rfcomm0 command, I realized later.) I still would like to find out how I could connect to the HC-06 module without having to give all the bleutoothctl commands.

I also tried to build my Acorn Atom emulator, which I succeeded to do after some modifications to the make file with respect to include directories and dependencies (make depend did not work). When I executed it, a window displayed, and a lot of messages about illegale opcode, because the Acorn Atom Roms were not included in the start-up directory. I must have them somewhere or see if I can use the Acorn ROMs.

Monday, July 25, 2016


Sunday, July 24, 2016


Saturday, July 23, 2016


I visited the TETEM art space. I first looked at the exhibition Gogbot Tribute to Remko Scha. I enjoyed listen to and looking at The Machines by Remko Scha. I also liked "No Noise II" by Jochem van der Spek. Next, I looked at Multi Solo: The Rhythm Painter. I liked the music of The missile knows where it is by Nils Mühlenbruch. I was not very impressed by the three video and sound works under the artist name microseq of Pandelis Diamantides. Finally, I looked at the exhibition The Rhythm Painter: Shape Your Identity with the Shape your identity installation, a machine that makes music and images (appearantly not working when I was there) based on a fingerprint scan. You can also turn some knobs and push some buttons to change the music. But the effect of this seems to be minimal. Nevertheless, I enjoyed playing with it. This time all the exhibition rooms did have something with sound in it.

Thursday, July 21, 2016

Star Trek: Beyond

This afternoon, I went to see the movie Star Trek: Beyond. To be honest, I was a little disappointed. On positive point that I have to make is that the way in which Zachary Quinto portraits Spock is becoming more like how Leonard Nimoy portraited him. I guess, I am disappointed because this movie looks too much like all other superhero action movies that are around today. There are only dialogues that go a little deeper, such as the moment that Spock becomes philosophical about death.

Wednesday, July 20, 2016


Tuesday, July 19, 2016


August 2016
July 2016
June 2016
May 2016
April 2016
Alzheimer's Disease
Trip to China 2010
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