More about Linus Torvalds. How Linux was created

We continue to celebrate 29 years of Linux contating aspects of the life of its creator Linus Torvalds. We are relying on a book which he published in 2001.

More about Linus Torvalds

With money raised from birthdays, summer jobs as a publicity delivery man, cleaning public parks, birthdays and school awards (Finnish schools seem to distribute cash to their students) Linus raised the money to buy a computer more powerful than his grandfather's Commodore VIC 20. He opted for a Sinclair QL, a 32-bit computer with a multitasking operating system, a Motorola's 68000 8 Megahertz processor and 128 kb of memory.

Young Torvalds used this computer For various programming projects, he learned the Forth language (very popular in the 80s) and wrote his own programming tools and upgraded clones of his favorite VIC 20 games. He also bought a disk drive, but since he did not like how the controller worked, he chose to write his own.

He acknowledges that it was the writing of the new driver that sparked his interest in operating systems. While writing it, he found errors in the documentation that made what he had written did not work so he decided to learn how the one on the Sinclair QL worked.. He did this with books and a tool called disassembler that serves to convert the machine language to a low-level but more understandable for humans called an assembler.

The Sinclair QL lasted three years for Linus after which he began to tire of his limitations and sell his peripherals.

After leaving the army and while waiting to resume his university studies, Torvalds found a book that in his own words changed his life. "Operating Systems": Design and Implementation, by Andrew S. Tanenbaum. It was actually one of the texts she would need in the fall course, but she decided to start reading it sooner.

Tanenbaum is the creator of Minix, an operating system created with the aim of teaching people to understand how Unix works. By reading the book and using Minix, Linus fell in love with the operating system created by Bell Labs.

His first experience with Unix was in a course with a teacher who didn't know much more than his students. Linus says that the teacher was one chapter ahead of the students and that they used to ask him questions from later chapters to make him look bad. That same year he attends a Richard Stallman conference although he admits that at that time he was not interested in free software.

On January 2, 92, Linus Torvalds bought on credit a white label PC armed with components of his own choosing. The chosen operating system was Minix. As Minix had limited features (It had been created for educational purposes) various people had created patches that increased its functionalities that it also installed.

To connect with the University computer, he created his own terminal emulator, but since he wanted it to run at first he had to learn how the 386 CPU worked.

That computer, with which Linux was written, would end up being paid for with a collection organized by the first users.

Linus decided that he wanted his terminal emulator to allow him to download and save files. That required programming a disk controller and a file manager. The file manager made it compatible with Minix's, not only because it was well documented but because he wanted to be able to see the files when he was not connected to the university computer. It was at this point that he realized that the project had been transformed into an operating system.

Once the decision was made, Torvalds asked a Minix user group for information about POSIX standards. So as not to screw up trying to explain what it's about, I'm going to quote to Wikipedia:

POSIX is a written standard and a registered trademark of the Institute of Electrical and Electronics Engineers. This standard defines a standard interface of the operating system and the environment, including a command interpreter (or "shell"), and common utility programs to support the portability of applications at the source code level.

What you get is an offer of space on the ftp servers of the Helsinki University of Technology to host the new operating system. For POSIX standards, he had to make do with manuals he found at the university.

The rest of the story already know it.