[Simh] pdp11 and unix

[Gregg Levine]

Hello!
Version Zero was hand coded on a PDP-7. Included the necessary tools
to make the tools, that is the components we use now on the ones on
the PDP-11 to write programs.

As I understand it, but I believe there are people on the list who
know more then I do,and can chime in; the gang at Bell Labs started
with a spare PDP-7 that one of the group there felt lonely for. Once
they were ready to move past Version Zero and move towards the one we
know it became necessary to move the code to a PDP-11, and from there
they probably had to redo a heck of a lot of things, but oddly enough
it all worked after a fashion.

I've seen Assembler output from a PDP-11 someplace. It's always
reminded me of a frustrated 6502 microprocessor or a 6800 series one.
But only just.

As I said folks, if I've left out anything or did not get the full
story done right please feel free to chime in.
-----
Gregg C Levine gregg.drwho8 at gmail.com
"This signature fought the Time Wars, time and again."


On Thu, Feb 25, 2016 at 9:34 PM, Bill Cunningham <billcun at suddenlink.net> wrote:
>
>
> ----- Original Message -----
> From: Clem Cole
> To: Bill Cunningham
> Cc: SIMH
> Sent: Thursday, February 25, 2016 9:22 PM
> Subject: Re: [Simh] pdp11 and unix
>
>
> On Thu, Feb 25, 2016 at 7:50 PM, Bill Cunningham <billcun at suddenlink.net>
> wrote:
>>
>> When Ken Thompson coded UNIX it was in assembly.
>
> Correct...
>
>
>
>>
>> The first versions anyway before B/NB/C
>
> I do not think that is 100% correct.  B and early UNIX sort of come about at
> the same time.   B (and its pseudo model - BCPL) has only one data type (a
> word) and that works because UNIX was originally implemented on a word
> addressed machine.
>
> NB/C comes out when the Ken starts moving to the 11 which was byte
> addressed, as opposed to word addresses of it's predecessors.
>
> What model PDP was the first UNIX written on. All I know of s the PDP11.
>
> Bill
>
>
>
> _______________________________________________
> Simh mailing list
> Simh at trailing-edge.com
> http://mailman.trailing-edge.com/mailman/listinfo/simh