Re: Address bits again, Article on new mainframe use

On Wed, 11 Sep 2024 01:53:42 -0000 (UTC), John Levine wrote:

According to Lawrence D'Oliveiro  <ldo@nz.invalid>:

>
On Mon, 9 Sep 2024 16:55:44 +0000, MitchAlsup1 wrote:
>

With pages you can swap parts of a segment (page at a time) with
segmentation (only) you cannot swap parts of the segment.

>
Mixing the two seems counterproductive, unless you have few, large
segments. Burroughs-style segments were smaller and more numerous than
that.

 
Multics had paged segments.  The segments were as I recall 18 bit word
addressed so about a megabyte.  The pages were perhaps 1K.  It worked
pretty well.

That’s what I mean about “large” segments. I think the segment size
limited the file size as well.

An underappreciated advantage of paging is that the pages are all the
same size.

Nothing underappreciated about it. It’s the reason why we have pages
nowadays and no segments.