7. MIT Hacker Culture and ITS

From Model Trains to Computers

MIT's hacker culture started with the Tech Model Railroad Club at MIT. This club built a model railroad and developed relay systems to keep the trains from colliding with each other[1].

For reference, the video below shows how a computer can be used to control moving model trains.

The PDP series, made by Digital Equipment Corporation (DEC), contributed greatly to hacker culture, and later models provided an important environment for the birth of free software. These relatively inexpensive computers were particularly popular at universities and helped establish the minicomputer category. For reference, DEC donated a PDP-1 to MIT in 1961[2].

Late Nights and Spacewar!

Members of the Tech Model Railroad Club spent more time with the TX-0 and, later, the PDP-1.

For fun, the students created one of the earliest and most influential computer games, called Spacewar![4].

The AI Group and the Birth of ITS

MIT's early hacker community also had close ties to the AI research group led by Marvin Minsky, a pioneer of artificial intelligence, and John McCarthy, the creator of Lisp. Their involvement spanned different periods: McCarthy moved to Stanford in 1962[6], while Richard Stallman joined the MIT Artificial Intelligence Laboratory (AI Lab) much later, in 1971[7].

When Project MAC began in 1963, Minsky's AI group became part of it[5]. Another group within Project MAC was developing an operating system called Multics with GE and Bell Labs. MIT's initial Multics system used the GE-645[8].

But the AI programmers disagreed with the direction of Multics' design and began developing their own operating system, ITS (Incompatible Timesharing System), in 1967[3]. In 1970, the group split from Project MAC to become the independent AI Lab[5].

MIT hacker Tom Knight (right) developed the first kernel for ITS.

Actual development started on the PDP-6, and it was all written in assembly language.

An Open System and a Culture of Sharing

At the time, the ITS operating system had a unique user environment rarely found today. In the early days, people could use the system without logging in, and users who identified themselves did not need a password. All files, including documentation and source code, could be edited by anyone.

In addition, it was possible to access ITS not only inside MIT but also from other institutions or schools through ARPAnet. The wide-open ITS philosophy and collaborative online community had a great impact on hacker culture and the free and open source software movement, and anticipated the open, collaborative knowledge-sharing model later embodied by wikis[3].

Richard Stallman, who later started the free software movement, also participated in the development of the ITS operating system as a member of the community while working at the MIT AI Lab beginning in 1971, where he was influenced by the hacker culture.

At many institutions, software was treated as part of the hardware package and was shared and used without separate payment. Some companies also distributed their software with source code, allowing users to modify and copy it.

These practices were not universal; commercial software already existed too.

References

1. Hacker, Wikipedia
2. PDP-1, Wikipedia
3. Incompatible Timesharing System, Wikipedia
4. Spacewar!, Computer History Museum
5. Project MAC, Multics History Project
6. John McCarthy, Wikipedia
7. The GNU Project, Richard Stallman
8. GE-645 Multics System, Artist's Rendition, MIT, Jerome H. Saltzer