That erodes part of my argument. Why did C overtake Pascal? If it wasn't performance or availability, was it just preferences? Or portability from other existing codebases?
UNIX was the only OS where C was relevant, and AT&T was forbidden to sell it, so they made the source code available to universities and companies for a nominal price.
That was already a big difference, instead of paying a sum of several thousands for closed source OS stuck to a specific mainframe, companies and universities could get something with source code for about $70 (if I remember correctly).
Thus UNIX eventually became the foundation of 80's startups like Sun and SGI.
Home computers firmware was basically Assembly, where C (actually K&R C dialects) was yet another language among all the available ones.
When the 16 bit revolution happened, there were several 16 bit computers systems done in a mix of Pascal and Assembly. The most notable ones Apple Lisa, Mac OS, MicroEngine and Corvus Concept.
So you had UNIX variants gaining a foothold on university campus and companies, with people wanting to write applications on their tiny (cheaper) computers at home, which like JavaScript and the Browser nowadays, C eventually escaped UNIX.
Apple eventually gave in to market pressure and rewrote their Object Pascal based SDK into C++ and C. And even tried their first stint at UNIX with A/UX.
C by virtue of being UNIX's system language meant that its tooling was free with the OS, while any other programming language had to be bough separately and still you would need to write FFI to C at some level.
As side note, eventually C compilers stopped being available for free when Sun started the trend of selling the SDK, which made the largely ignored gcc to start getting contributions.
While this was happening, Brian Kernighan decided to push for C, with articles like
"Why Pascal is Not My Favorite Programming Language"
Which ignored the fact that the majority of Pascal dialects had features that covered his complaints, specially the second ISO revision, Extended Pascal. And that outside of UNIX most C compilers were actually dialects, which is one of the causes for UB.
There were other bash articles flying around like "Real Programmers Don't Use PASCAL".
On the PC world, OS/2 and Windows were being written in C, but the majority of application developers were actually already jumping with C++ wit C Set++ for OS/2, OWL, VCL and MFC on Windows.
Another nascent PC OS, BeOS, was also being written in C++.
It was the rise of FOSS UNIX software, with C as its systems language, that shifted the balance towards C. To stress it again, just like JavaScript on the browser.
If you look at the history of systems programming languages, the ones that lasted longer were always the ones that were the way to write software for a specific OS.
Regarding Pascal, the majority of vendors started to consider Turbo Pascal as the pseudo-official standard, which when Borland decided to ignore small developers and focus on the enterprise, just kind of killed the Pascal market. Specially since Turbo Pascal was only focused on PC.
There is probably a bit more to rant about, but I guess you get the idea.
This was hugely useful to me, and I appreciate the copious links. But I am still stuck on something. In the early days, you programmed the home computers with assembler (it was the truth) or you used co-equal non-truth languages like C or Pascal. Later on, the OSes were all written in C, so the application code was being written in C (or mixed C + assembler) and you had FFI problems if you weren't using C. But what happened in between these that caused the OSes to be written in C rather than Pascal? Was Pascal just not perceived to be useful as a systems language?
Politics and Unix would explain it if, people were borrowing and/or aping Unix in their OSes, or if people just generally had the impression that C was more powerful. Is that kind of the direction you're pointing?
Then we moved into 16 bit, the major platforms being MS-DOS, Lisa and MacOS, Atari and Amiga.
MS-DOS was coded in Assembly, Lisa and MacOS in Object Pascal, Atari and Amiga used a mix of Assembly and BCPL.
MS-DOS and AmigaOS had quite a few UNIX influences on them.
Regarding my experience in Portugal, MS-DOS applications were being mostly programmed in Assembly, Pascal, C, C++, Basic and Clipper. Then there were some outliers using Prolog, Modula-2, Forth.
Microsoft and Borland were the two biggest vendors on the market and supported almost the same set of languages, with Borland ones being more programmer friendly.
Amiga were usually programmed in Assembly, Basic, AMOS, Modula-2 and C.
Mac OS was using Object Pascal until by System 7 release they decided to switch to C++.
UNIX started to be quite relevant by the mid-90's, and many wanted to continue the work on their home computers, that were doing at work or university on the expensive computer centres running some form of UNIX.
For example, I wrote K&R C code on MS-DOS for OS classes where the teacher would bring a PC tower into the class running Xenix, where each group would get a turn trying to execute their UNIX assignments.
Think a bit like how the Web influenced the desire to have JavaScript everywhere with node, it was a similar experience.
UNIX was being adopted by companies, the other contender being VMS (using BLISS as systems language).
With C companies had an ANSI/ISO standard ratified in 1989, while with Pascal, there was a de facto standard Turbo Pascal/Object Pascal with ISO being largely ignored, but they were confined to MS-DOS/Mac OS.
One nit: "Why Pascal is Not My Favorite Programming Language" explicitly states that it is not a comparison of Pascal and C. "Real Programmers Don't Use PASCAL" was not a "bash" article; it was satire. It didn't advocate use of C, even in satire - it advocated Fortran and assembler.
I think blaming either of those articles is mistaken.
