Rich kids are into COBOL

Johnny Billquist bqt at
Fri Feb 27 15:18:19 CST 2015

On 2015-02-27 20:52, Eric Smith wrote:
> On Fri, Feb 27, 2015 at 11:27 AM, Chuck Guzis <cclist at> wrote:
>> It seems to me to be very strange that today we're coding in a language that
>> was developed for a PDP-11 minicomputer.
> Developed for the PDP-7, actually.  Contrary to popular belief, the
> "++" and "--" operators were NOT the result of the PDP-11 addressing
> modes.

No, C was developed for/on the PDP-11. Unix was originally implemented 
on a PDP-7, but that was all in assembler. It was then ported to the 
PDP-11, and then rewritten in C.

And yes, the ++ and -- was not related to the PDP-11 instruction 
argument forms, even if they make some of it easier. This has been 
publicly explained by DMR in the past. The post/mail should be easy to find.

There is a second discussion about C and the PDP-11, which centers 
around the floating point mode, which might actually come from the 
PDP-11 architecture peculiarity. (I'm sure someone can dig up the 
details of that one if they are interested.)


Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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