Does anybody know how much memory was configured on the PDP-11 that 
Lion's used for the commentary system. Here's what the book says about 
the system:

; from lions, page 1
; The code selection presumes a "model" system consisting of:
; PDP11/40 processor;
; RK05 disk drives;
; LP11 line printer;
; PC11 paper tape reader/punch;
; KL11 terminal interface.

I usually add the mag tape, too
; TM10 magnetic tape - not in lions, but super handy

It seems like he must have had an MMU and 128k memory, but I don't know. 
I'm hoping y'all remember, know, or can otherwise divine the correct 
value. I've run with no MMU - crash on boot. I've also run with less 
memory, but then cc won't build mkconf, when I have the TM10 enabled 
kernel loaded. As a reminder, his book was published in 1977.

Thanks,

Will