🚀 go-pugleaf

On 3 Feb 2018 10:52:00 GMT, Bob Eager <news...@eager.cx> wrote:

>On Sat, 03 Feb 2018 03:41:11 +0000, Melzzzzz wrote:
>
>>>>The problem we're having is that noone, especially the operating
>>>>systems, keeps the user actions separated from system actions.  There
>>>>should have been a strict wall between the two functionalities. TOPS-10
>>>>and TOPS-20 got this right via the UUO interface.  Unix and MSoft's
>>>>developers, over the years, got lazy while writing new code and didn't
>>>>keep a strict wall between the two.
>>>
>>> I think you will find that the opposite has occurred.  Early PCs didn't
>>> even have the means to enforce such a wall.  Now modern operating
>>> systems run just about everything in userspace at some level of
>>> virtualization.
>> 
>> Correct. 286 had protected mode, but almost no OS used it...
>
>The only systems I can think of were some nice UNIX-like systems, 
>including IBM's PC-IX. It didn't help that protected mode was 
>incompatible address-wise with real mode.

AT&T System V is another example (yes, there was a real Unix for the
286).  Also Novell Advanced Netware 286, which was not Unix like at
all.

The big obstacle was a bug that corrupted one or more registers when
switching from protected back to real IIRC.  One developer dealt with
this by saving the register values into the keyboard buffer and
reading them back after the switch.

>Barb seems to be implying that the UUO interface was something new (but 
>then we know her only experience is DEC!). I can think of plenty of 
>examples on other systems and hardware.