LISP implementations on small machines

[Noel Chiappa]

    > From: Paul Koning

    > Some early machines, the PDP-6 I believe is an example, have
    > "registers" in the ISA but they actually correspond to specific parts
    > of main memory.

The PDP-6 and KA10 (basically a re-implementation of the PDP-6 architecture)
both had cheapo versions where addresses 0-15 were in main memory, but also
had an option for real registers, e.g. in the PDP-6: "The Type 162 Fast
Memory Module contains 16 words with a 0.4 usecond cycle." The KA10 has
a similar "fast memory option".

	Noel