[ih] NCP, TCP/IP question

[Steve Crocker]

If memory serves, prior to Multics and Unix and with the exception of the
Burrough’s computers, operating systems were written in the assembly
language of the machine.  This includes the Sigma 7 (host 1), the SDS 940
(host 2), the IBM 360 (host 3) and Tenex (host 4).  The NCP (“Network
Control *Program*") was an addition to the existing code of the operating
system and, I believe, written in the same language as the operating
system.  I think C appeared with Unix.  I don't think C was used or
available on Tenex, but I'm not the most authoritative source.  I don't
know much about the later implementations of NCP.  PDP-11s became popular
and there were several operating systems written for them.  ELF (Dave Retz
in Santa Barbara) and ANTS (University of Illinois) come to mind, and I
think there were others.  At the time, I had the impression writing network
compatible operating systems for the PDP-11 was a cottage industry.

It would be interesting to compare the timelines of the transition from NCP
to TCP/IP with the evolution of hosts from the Tenex era to the Unix era.

Steve

On Tue, Mar 10, 2020 at 2:09 AM Vint Cerf <vint at google.com> wrote:

> NCP was probably done in assembly language for most operating systems -
> adding steve crocker for comment
> TCP was written in BCPL at Stanford for PDP-11/40. Probaby C for Tenex.
> PL/1 (?) for 360's???
>
> Let me ask the Internet History list.
>
> v
>
>
> On Tue, Mar 10, 2020 at 2:03 AM Steve Kirsch <stk at m10.io> wrote:
>
>> Was it written in C? you’d think only a small part would have to be
>> customized for the operating system?!
>>
>>
>>
>> *From:* Vint Cerf <vint at google.com>
>> *Sent:* Monday, March 9, 2020 1:59 AM
>> *To:* Steve Kirsch <stk at m10.io>
>> *Subject:* Re: NCP, TCP/IP question
>>
>>
>>
>> 1. NCP was written individually for each operating system
>>
>> 2. TCP was also written for each operating system but UNIX propagated
>> most widely; TENEX version was popular for PDP-10s.
>>
>> Bob Braden did the TCP for IBM 360/91 and I think that got ported to
>> 360/75 at UCSB. Berkeley BSD 4.2 and follow-ons was most widely spread for
>> UNIX.
>>
>>
>>
>> v
>>
>>
>>
>>
>>
>> On Mon, Mar 9, 2020 at 4:15 AM Steve Kirsch <stk at m10.io> wrote:
>>
>>
>>    1. Did UCLA provide the source code for NCP and TCP/IP for various
>>    places to run?
>>
>>
>>
>>    1. Or did everyone write their own implementation based on the spec?
>>
>>
>>
>> If the latter, was that problematic? Would it have been easier if
>> everyone ran Unix and there was C source code that was distributed to
>> everyone to run? Is that in fact what in fact happened? Why UCLA lost their
>> SEX and became EUNUCHs… I mean UNIX?
>>
>>
>>
>>
> --
>>
>> New postal address:
>>
>> Google
>>
>> 1875 Explorer Street, 10th Floor
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>>
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>>
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>>
>> <https://www.google.com/maps/search/1875+Explorer+Street,+10th+Floor+%0D%0A+%0D%0A+%0D%0A+Reston,+VA+20190?entry=gmail&source=g>
>>
>> Reston, VA 20190
>> <https://www.google.com/maps/search/1875+Explorer+Street,+10th+Floor+%0D%0A+%0D%0A+%0D%0A+Reston,+VA+20190?entry=gmail&source=g>
>>
>
>
> --
> New postal address:
> Google
> 1875 Explorer Street, 10th Floor
> <https://www.google.com/maps/search/1875+Explorer+Street,+10th+Floor+Reston,+VA+20190?entry=gmail&source=g>
> Reston, VA 20190
> <https://www.google.com/maps/search/1875+Explorer+Street,+10th+Floor+Reston,+VA+20190?entry=gmail&source=g>
>