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* [COFF] Supervisor mode on ye olde PDP-11
@ 2024-06-19  6:49 Dave Horsfall
  2024-06-19  7:48 ` [COFF] " Warner Losh
  2024-06-19 11:11 ` Milo Velimirović
  0 siblings, 2 replies; 3+ messages in thread
From: Dave Horsfall @ 2024-06-19  6:49 UTC (permalink / raw)
  To: Computer Old Farts Followers

Sort of between kernel and user mode, Unix [zillion trademarks etc] never 
used it. but did RSX-11?

I used the latter long enough to hate it until Edition 5 arrived at UNSW, 
and I still remember being blown away by the fact that there was nothing 
privileged about the Shell :-)

-- Dave

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [COFF] Re: Supervisor mode on ye olde PDP-11
  2024-06-19  6:49 [COFF] Supervisor mode on ye olde PDP-11 Dave Horsfall
@ 2024-06-19  7:48 ` Warner Losh
  2024-06-19 11:11 ` Milo Velimirović
  1 sibling, 0 replies; 3+ messages in thread
From: Warner Losh @ 2024-06-19  7:48 UTC (permalink / raw)
  To: Dave Horsfall; +Cc: Computer Old Farts Followers

[-- Attachment #1: Type: text/plain, Size: 503 bytes --]

On Wed, Jun 19, 2024, 1:37 AM Dave Horsfall <dave@horsfall.org> wrote:

> Sort of between kernel and user mode, Unix [zillion trademarks etc] never
> used it. but did RSX-11?
>

2.11BSD used a mode between kernel and user for the TCP stack to get more
effective address space...

Warner

I used the latter long enough to hate it until Edition 5 arrived at UNSW,
> and I still remember being blown away by the fact that there was nothing
> privileged about the Shell :-)
>
> -- Dave
>

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^ permalink raw reply	[flat|nested] 3+ messages in thread

* [COFF] Re: Supervisor mode on ye olde PDP-11
  2024-06-19  6:49 [COFF] Supervisor mode on ye olde PDP-11 Dave Horsfall
  2024-06-19  7:48 ` [COFF] " Warner Losh
@ 2024-06-19 11:11 ` Milo Velimirović
  1 sibling, 0 replies; 3+ messages in thread
From: Milo Velimirović @ 2024-06-19 11:11 UTC (permalink / raw)
  To: Dave Horsfall; +Cc: Computer Old Farts Followers

> On Jun 19, 2024, at 1:49 AM, Dave Horsfall <dave@horsfall.org> wrote:
> 
> Sort of between kernel and user mode, Unix [zillion trademarks etc] never 
> used it. but did RSX-11?

I don’t know about RSX-11.

Back to UNIX: Supervisor mode probably never ran any code, but its memory management registers were used in m45.s in functions copyseg and clearseg. 

—Milo



^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2024-06-19 11:11 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2024-06-19  6:49 [COFF] Supervisor mode on ye olde PDP-11 Dave Horsfall
2024-06-19  7:48 ` [COFF] " Warner Losh
2024-06-19 11:11 ` Milo Velimirović

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