[TUHS] BTL summer employees

Noel Chiappa jnc at mercury.lcs.mit.edu
Mon Aug 10 22:53:22 AEST 2020

    > From: Lars Brinkhoff

    > the Dover printer spooler was written using Snyder's C compiler

I'm not sure if that's correct. I don't remember with crystal clarity all the
details of how we got files to the Dover, but here's what I recall (take with
1/2 a grain of salt, my memory may have dropped some bits). To start with,
there were different paths from the CHAOS and TCP/IP worlds. IIRC, there was a
spooler on the Alto which ran the Dover, and the two worlds had separate paths
to get to it.

>From the CHAOS world, there was a protocol translation which ran on whatever
machine had the AI Lab's 3Mbit Ethernet interface - probably MIT-AI's
CHAOS-11? If you look at the Macro-11 code from that, you should see it - IIRC
it translated (on the fly) from CHAOS to EFTP, the PUP prototocol which the
spooler ran 'natively'.

>From the IP world, IIRC, Dave Clark had adapted his Alto TCP/IP stack (written
in BCPL) to run in the spooler alongside the PUP software; it included a TFTP
server, and people ran TFTP from TCP/IP machines to talk to it. (IP access to
the 3Mbit Ethernet was via another UNIBUS Ethernet interface which was plugged
into an IP router which I had written. The initial revision was in Macro-11; a
massive kludge which used hairy macrology to produce N^2 discrete code paths,
one for every pair of interfaces on the machine. Later that was junked, and
replaced with the 'C Gateway' code.)

I can, if people are interested, look on the MIT-CSR machine dump I have
to see how it (a TCP/IP machine) printed on the Dover, to confirm that
it used TFTP.

I don't recall a role for any PDP-10 C code, though. I don't think there was a
spooler anywhere except on the Dover's Alto. Where did that bit about the
PDP-10 spooler in C come from, may I enquire? Was it a CMU thing, or something
like that?


More information about the TUHS mailing list