Cover Letter

 

Warning: another technical post.The duckrabbitI wrote this cover letter many years ago, when I wanted to get accepted to the Matzov unit of the Israeli Defense Force (in Israeli, every male is conscripted for three years at age 18, and I wanted to put my skills to good use.)

Like the picture above, it can be interpreted two different ways. You could read it as a letter in the English language explaining why my skillset is a good fit Matzov… or you could read it as a program in the Brainfuck programming language (can you tell what it does?) This is made possible because most characters in the English alphabet are considered comments in Brainfuck. Still, writing it required pulling an awful lot of tricks.

On the right you can see a size-optimized hand-coded 8086 assembly language Brainfuck interpreter, and instructions on how to execute it. While writing the letter took a few hours, writing the interpreter took three days without sleep. Shaving the last byte off took almost half a day.

Matzov Cover

Click for full version.

Notice how periods are meaningful commands in Brainfuck, so there’s a question of whether the periods on the right are or aren’t part of the program. In practice, it doesn’t matter because if they were, they would be after an infinite loop and never actually execute.

Edit: Hi HN. At your request, here‘s a .txt I extracted from the .pdf.

Advertisements