Ken Thompson Wrote an OS in 3 Weeks: The Untold Story of Unix
Learning about "The Unix Time-Sharing System"
This deep dive into Dennis Ritchie and Ken Thompson's classic paper uncovers the surprising origins of Unix, from Thompson's quest to optimize disk throughput on a GE-645 to his wife's three-week vacation that gave him time to finish the OS. It highlights the revolutionary concept of separating data from programs, the birth of the exec system call, and the legacy of 'runcoms' in today's /etc/rc scripts. A must-read for anyone curious about how Unix's design principles still shape computing.
The peripherals were great...it had a set of disks that were faster than anything that I could imagine, and I wanted to write drum seeking algorithms, I wanted to get throughput on drums because everything I knew in the computer center or in Multics couldn't deal with drums well...Basically they would say "read" and wait for the read to come back, but what you want to do is simultaneous overlapped reads.
- gwynforthewyn
I'm the writer of this essay.
My subject is some details surrounding the first white paper that Bell Labs published about Unix was "The Unix Time-Sharing System". I wrote what Ken Thompson was doing in between the end of Multics but before he found the "little used PDP-7" that he wrote Unix on, the difference between opening files on Multics and Unix, and what the "comfile" mentioned in the paper is.
I wrote this without AI involvement; I follow Unix history because I love knowing what the history is and what I can learn from it, and I love showing others these sorts of cool details.
I'd love to hear any feedback you might have :)
- bch
> So what's a comfile? Clearly it's a shell script, yeah? So why're they called comfiles? It's short for "command files".
The vestige I'm amused by on my (BSD) systems is <foo>.S files. "S" for "Source". From the time when "source code" meant "assembly". Python, zig, C++, C, etc would be invented later...