On Fri, Feb 16, 2018 at 10:44 AM, Mike Stramba <mikestra...@gmail.com> wrote: > Thanks Guys. > > I *had* downloaded a handbook... but it was the *oldest* one (1969) > ;), hence no mention of virtual memory in it ;)
Yeah, Once you get to anything with an 18-bit Unibus, there's a distinction. What's sometimes hard to get used to is for the PDP-11, virtual space is *smaller* than physical space. Virtual space is 64K. Physical space can be up to 4MB depending on the model. I started on a VAX with 2MB of physical memory in a 16MB physical address space but with 4GB virtual addresses. Switching over to the PDP-11 was odd from that. -ethan _______________________________________________ Simh mailing list Simh@trailing-edge.com http://mailman.trailing-edge.com/mailman/listinfo/simh