out-of-mainstream minis

Brian L. Stuart blstuart at bellsouth.net
Sat Jul 4 20:09:44 CDT 2015

> Ok. I didn't know it was some version of 7th ed. I didn't even know that 
> managed to get much beyond the PDP-11.

At least that's the way I read the original message.  And there were
a number of re-implementations/clones of 7th ed.
> Anyway, it's sad, because the PDP-11 hardware can easily
> handle demand paged memory. It's just that no one really
> found it worth the effort to  implement it when you only have
> 8 pages, and have way more physical memory than the
> virtual memory space can address.

It turns out that at one time, there was an experimental version
of UNIX at the labs that did do demand paging on an 11.  They
didn't continue that line of development because it didn't end
up giving any significant benefits but ran slower than a swapping
based approach.

>> It's only a leak.  ...
> Thanks. I was trying to remember which, but my brain failed me.

You're welcome.  I didn't remember for sure either, so I had to
look it up.


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