PDP-11 pages/segments/etc (Was: PDP-12 at the RICM)

Noel Chiappa jnc at mercury.lcs.mit.edu
Tue Jul 14 12:52:56 CDT 2015


    > On Jul 13, 2015, at 8:52 PM, Johnny Billquist <bqt at update.uu.se> wrote:

    > ??? What segments??? The PDP-11 have a plain simple page table. No
    > segments anywhere in sight. And each page is 8K.

I know the processor handbook calls them 'pages', but I can't think of any
other machine where pages are variable size. (I know of a couple which offer
_two_ page sizes, but none that have a field per page which specifies the
length of the page.)

They really are more like what most machines call 'segments'. I know Unix
doesn't use them that way (because it has such a simple-minded memory model),
but other systems do - e.g. MERT.

	Noel


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