LISP implementations on small machines

Stan Sieler sieler at
Fri Oct 4 01:16:53 CDT 2019

David...where did you use Lisp on a B6700?

Bill Gord and I wrote the first INTERLISP interpreter for the B6700 back
1974-1975, on a DARPA contract, at UCSD.  (At the start, it was to
implement BBNLISP,
but the name changed during the project :)

DARPA found that researchers using INTERLISP (or others) on Dec PDP10s (and
similar) were hampered by the limited address space (256K virtual memory).
The B6700 offered a significantly larger address space (and many other
features, of course :)
(I know our LISP got distributed to other Burroughs sites in those days,
just like our STARTREK and Bob Jardine's SOLAR.)

Danny Bobrow (with Xerox PARC at the time) came and helped us get started.
I met Warren Teitelman ... he had no idea that the cover of the
INTERLISP manual was an homage to his last name.  (See:

We got our system up and running, including DWIM and other packages, and
were told ... oops, DEC figured out how to expand the amount of virtual
memory on the PDP-10, so we don't need to buy Burroughs mainframes now!

Our INTERLISP was a full interpreter, and also had a compiler to LISP
p-code, which might have inspired UCSD Pascal's p-code (Ken Bowles was our

I believe I have the source, in Burroughs ALGOL.

As a side bonus, I got to interact with Danny, and people from PARC and BBN
as we were watching other UCSD Computer Center people put the B6700 on the
ARPANET.  (I think we were something like the 25th computer.)

Stan Sieler

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