4 ms·

First C compiler source code from 1972

75 points by cft 2y ago

cpr 2y ago
Wow, that brings back memories! First saw the C compiler sources on Geoff Steckel (local guru)'s desk around 1973 at the Harvard graduate computing center, and was absolutely floored at this fascinating-looking language. (Harvard got the first Unix tapes outside of Bell Labs; not sure of the connection there.) All upper-case, of course, as the DEC lineprinters didn't have lower case yet. Real upper case was struck-through upper.
ytch 2y ago
Dupe of: https://news.ycombinator.com/item?id=43433030 https://news.ycombinator.com/item?id=43433030
zahlman 2y ago
> These are not capable of being compiled today with modern c compilers like gcc Is that only because it includes PDP-11 assembly code, or has the language changed too much?
- sanxiyn 2y ago
  As documented in http://cs.bell-labs.co/who/dmr/chist.html http://cs.bell-labs.co/who/dmr/chist.html, the primary incompatibility is uses of =+ for +=. Grep for =+ in the repository.
  - makeset 2y ago
    That's sed-able, if it were just that.
- vaxman 2y ago
  PDP-7 Macro Assembler BTW, Unix on DEC hardware was never really popular outside of academia so DEC's machines were primarily programmed in FORTRAN, BASIC or Macro assembler, but there were still several third-party C compilers (for RT11, RSX11, RSTS/E, TOPS and VMS). My shop had spun off of Bell Labs so we had just a few Unix weirdos running things, but the bazillion dollar VAXcluster only ran VMS, so they made us all use Whitesmith's C (which they would incorrectly pronounce with three syllables) which was horrible - so was constantly getting in trouble for continuing to work the evil FORTRAN77 ways 'til one day a Lead (pear-shaped Unix grandmaster smellable from 20 feet away) dropped this on my desk with a thud http://www.bitsavers.org/pdf/dec/vax/lang/c/AA-L370A-TE_Programming_in_VAX_C_1.0_198205.pdf http://www.bitsavers.org/pdf/dec/vax/lang/c/AA-L370A-TE_Prog... Soon, I was spending my hard earned dollars on Lattice and Aztec C licenses for my own home-brew systems too. I resisted Unix to the very End tho #rofl
webprofusion 2y ago
It's cool but it's not getting any more newsworthy. Submitted 9 times to HN so far since 2013.
- n4r9 2y ago
  It's good to revisit old topics from time to time.
- rajamaka 2y ago
  I browse HN daily and have never seen it
  - johnisgood 2y ago
    https://news.ycombinator.com/item?id=43433030 https://news.ycombinator.com/item?id=43433030 (submitted 3 days ago, ~370 points). It is fine to not see it, however, that is why I am giving you the link, although someone else already posted it 6 hours ago (from now).
qq66 2y ago
How was the first C compiler written in C?
- zerr 2y ago
  If I remember correctly, it was written in B.
  - deleted 2y ago
    [deleted]
- mystified5016 2y ago
  It wasn't. You typically bootstrap a compiler by first writing a compiler in an existing language. Then you get a compiler that can sort of compile your langauge, but the bootstrapping language contaminates your assembly. So you iteratively compile the compiler with itself until it's purely in the new language. The very first compilers were bootstrapped from handwritten assembly. C was famously bootstrapped from B. GCC started in assembly I think and has been compiling itself for decades.
deleted 2y ago
[deleted]

75 points by cft 2y ago

cpr 2y ago

Wow, that brings back memories! First saw the C compiler sources on Geoff Steckel (local guru)'s desk around 1973 at the Harvard graduate computing center, and was absolutely floored at this fascinating-looking language. (Harvard got the first Unix tapes outside of Bell Labs; not sure of the connection there.) All upper-case, of course, as the DEC lineprinters didn't have lower case yet. Real upper case was struck-through upper.

ytch 2y ago

Dupe of: https://news.ycombinator.com/item?id=43433030 https://news.ycombinator.com/item?id=43433030

zahlman 2y ago

> These are not capable of being compiled today with modern c compilers like gcc Is that only because it includes PDP-11 assembly code, or has the language changed too much?

sanxiyn 2y ago
As documented in http://cs.bell-labs.co/who/dmr/chist.html http://cs.bell-labs.co/who/dmr/chist.html, the primary incompatibility is uses of =+ for +=. Grep for =+ in the repository.
- makeset 2y ago
  That's sed-able, if it were just that.
vaxman 2y ago
PDP-7 Macro Assembler BTW, Unix on DEC hardware was never really popular outside of academia so DEC's machines were primarily programmed in FORTRAN, BASIC or Macro assembler, but there were still several third-party C compilers (for RT11, RSX11, RSTS/E, TOPS and VMS). My shop had spun off of Bell Labs so we had just a few Unix weirdos running things, but the bazillion dollar VAXcluster only ran VMS, so they made us all use Whitesmith's C (which they would incorrectly pronounce with three syllables) which was horrible - so was constantly getting in trouble for continuing to work the evil FORTRAN77 ways 'til one day a Lead (pear-shaped Unix grandmaster smellable from 20 feet away) dropped this on my desk with a thud http://www.bitsavers.org/pdf/dec/vax/lang/c/AA-L370A-TE_Programming_in_VAX_C_1.0_198205.pdf http://www.bitsavers.org/pdf/dec/vax/lang/c/AA-L370A-TE_Prog... Soon, I was spending my hard earned dollars on Lattice and Aztec C licenses for my own home-brew systems too. I resisted Unix to the very End tho #rofl

webprofusion 2y ago

It's cool but it's not getting any more newsworthy. Submitted 9 times to HN so far since 2013.

n4r9 2y ago
It's good to revisit old topics from time to time.
rajamaka 2y ago
I browse HN daily and have never seen it
- johnisgood 2y ago
  https://news.ycombinator.com/item?id=43433030 https://news.ycombinator.com/item?id=43433030 (submitted 3 days ago, ~370 points). It is fine to not see it, however, that is why I am giving you the link, although someone else already posted it 6 hours ago (from now).

qq66 2y ago

How was the first C compiler written in C?

zerr 2y ago
If I remember correctly, it was written in B.
- deleted 2y ago
  [deleted]
mystified5016 2y ago
It wasn't. You typically bootstrap a compiler by first writing a compiler in an existing language. Then you get a compiler that can sort of compile your langauge, but the bootstrapping language contaminates your assembly. So you iteratively compile the compiler with itself until it's purely in the new language. The very first compilers were bootstrapped from handwritten assembly. C was famously bootstrapped from B. GCC started in assembly I think and has been compiling itself for decades.

deleted 2y ago

[deleted]