[ih] NCP and TCP implementations

[Dan Lynch]

The original TCP for Tenex was written in BCPL in user space (rather than in the underlying system space) and once it was reasonably stable it was converted to Macro-10 so it could be folded into the system. I believe Bill Plummer (RIP) did all that work. I helped him in the debugging tasks while I was at SRI. 

Dan

Cell 650-776-7313

> On Jul 21, 2020, at 6:43 PM, Noel Chiappa via Internet-history <internet-history at elists.isoc.org> wrote:
> 
> 
>> 
>> On 20.03.10, vinton cerf via Internet-history wrote:
>> 
>> Steve Kirsch asks in what languages NCP and TCP were written.
>> ...
>> Another version was written for PDP-11/23 by Jim Mathis but not clear in
>> what language.
> 
> I think I answered this when it was first posted, but I now have some
> additional data (I think).
> 
> It was written in MACRO-11; PDP-11 assembler with a powerful macro capability.
> After some poking around in a copy of the file system of the v6 Unix
> timesharing system of the CSR group at MIT, which has all sort of goodies in
> it (including a copy of the NCP for v6 Unix), I have recovered a copy of that
> TCP, if anyone wants it.
> 
> I'm not sure if it was done for the -11/23; we got MOS (Jim's OS, and other
> software, including the TCP and an early version of the Port Expander codea)
> early on, and I seem to recall that the -11/23 didn't come out until after we
> had MOS. I'd have to look up exactly when the KDF11 was released to be sure, if
> it's important. MOS had conditionals to work on the -11/03 and also the -11/20
> and -11/40 (binary for the -11/40 will run on the /23). I think the TCP, etc
> were written for the -11/03.
> 
>> Dave Clark did one for IBM PC (assembly language/??)
> 
> No, but Dave did I think at least two others; possibly one in BCPL? for the
> Tripos operating system from Cambridge, and definitely one in BCPL for the
> Alto (MIT got several as a donation from Xerox). Before the latter, he also
> worked on the Multics one (in PL/I) although someone else whose name my
> failing brain can't remember at the moment worked on that before him. The Alto
> one was later translated into C by Larry Allen for the CSR v6 Unix, which I
> used as the base on one I did for Bridge.
> 
> The one for the PC was done by John Romkey and David Bridgham, in C; the CSR
> machine dump has that one too, if anyone wants it.
> 
>    Noel
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