A LITTLE BIT OF HISTORY • Multix in the ’60s

The history of UNIX-like operating systems is a history of people being dissatisfied with what they have and wanting to do some-thing better. It started when Ken Thompson got bored with MUL-TICS and wanted to write a computer game (Space Travel). He found a disused PDP-7, and wrote an interactive operating sys-tem to run his game. The main contribution at this point was the simple file-system abstraction. Other people found it interesting enough to want to port it to other systems, which led to the first major rewrite — from assembly to C. In some ways UNIX was the first successfully portable OS. After Ritchie & Thompson (1974) was published, AT&T became aware of a growing market for UNIX. They wanted to discourage it: it was common for AT&T salesmen to say, ‘Here’s what you get: A whole lot of tapes, and an invoice for $10 000’. Fortunately educational licences were (almost) free, and universities aroun