On Friday, June 26, 2015 at 10:05:53 AM UTC-4, Bob Koehler wrote: > > I think you missed the 11/34. IIRC no MMU, only UNIBUS mapping > registers. I/O space was 18 bit, but RAM was 16. True. However, I saw WAY more 11/34A systems which did have an MMU. Was the 11/34 upgradable to the 11/34A or was it a system swap?