[TUHS] UNIX on (not quite bare) System/370

[Dan Cross]

On Thu, Dec 22, 2022 at 12:27 PM Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote:
>
>     > From: Bakul Shah
>
>     > There is a further para:
>
>     >  Reducing external memory fragmentation to zero by utilizing the VAX-
>     >  11/780 memory mapping hardware for scatter loading is high on the list
>     >  of things to do in the second implementation pass.
>
> I'm curious as to exactly what is meant by "external memory"? They must mean
> memory on the Synchronous Backplane Interconnect:
>
>   http://gunkies.org/wiki/Synchronous_Backplane_Interconnect
>
> I.e. what most of us would call 'main memory'.
> [snip]

I think you left off a critical word: "fragmentation."  I interpreted this to be
about external memory fragmentation a la memory allocators. As in,
https://en.wikipedia.org/wiki/Fragmentation_(computing)#External_fragmentation

Presumably, this would be less of an issue if they were actually making use
of the virtual memory hardware to compose contiguous virtual address spaces
from discontiguous physical memory pages.

        - Dan C.