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Diary, May 2021



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Sunday, May 2, 2021

Koffiegoot

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 1775.


Tuesday, May 4, 2021

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.


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