[TUHS] Unix with TCP/IP for small PDP-11s

Noel Chiappa jnc at mercury.lcs.mit.edu
Tue May 23 11:14:52 AEST 2017

    > From: Paul Ruizendaal

    > There are two other routes to TCP/IP on a PDP11 without split I/D:
    > ...
    > DCEC's adaptation of the Wingfield TCP/IP library, designed to work
    > with V6. It is mostly a user space daemon, but requires some kernel
    > enhancements.

I wonder what the performance would be like, since the TCP is in a user
process (a different one from the application), i.e. there's a process switch
every time the application goes to send or receive data. This wouldn't have
been such an issue when the code was written, since ARPANet-type networks
were not very fast, but with a better network, it would have been limiting.

    > From: Steve Simon

    > do you have pointers to any documentation on the rand/MIT network API?

There was no 'MIT' network API. He was talking about the CHAOSNet API. The
TCP/IP done in the CSR group at MIT used a totally different API.

The various Unix systems at MIT were pretty well out of touch with each other,
and did not exchange code. The only exceptions were the DSSR (later RTS) and
CSR groups in Tech Sq, who used pretty much the same system.


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