[Info-vax] CPU Refresher for Programmers

[Chris Scheers]

IanD wrote:
> On Monday, January 18, 2016 at 10:48:54 AM UTC+11, Chris Scheers wrote:
>> Stephen Hoffman wrote:
>>> On 2016-01-12 03:10:16 +0000, Stephen Hoffman said:
>>>
> 
> <snip>
> 
>> Conceptually, these "enclaves" look extremely similar to the Data 
>> General MV rings of 40 years ago.
>>
>> The only way to call code in a ring is through a defined call gate, 
>> outer rings can not access memory in an inner ring, etc.
>>
> 
> Oh I remember some DG stuff although it was when DG was in decline and Digital was growing and starting to eat their lunch from memory. We used it at an educational institute. I remember only being able to do 6 pascal compiles at a time, which was very painful in a class of 40 students waiting for a compile to get off the queue. We used to run spice circuit analysis on the DG as well. Wow, I had forgotten all about the DG system until mentioned here
> 
>> The way DG used it, the OS used the two innermost rings and user 
>> programs ran in the outermost ring.
>>
>> Intermediate rings received various subsystems.  User written subsystems 
>> were allowed.
>>
> 
> This was an idea I had about security and walling off various parts of an OS a long time back. I had forgotten all about it actually, not that it was ever more than a dreamy idea
> 
>> Among things, I've seen the intermediate rings running networking, 
>> databases, and cross process communications.  Anything that requires 
>> security from malicious (or just flakey) code is a good candidate.
>>

> I think the OS was Aviion? Didn't that morph into the OS behind EMC's storage frames?

The main MV OSes were AOS/VS and AOS/VS II.

IIRC, Aviion was the name originally used for their RISC hardware 
(Motorola 88000?).  The storage arrays were mostly under the Clariion 
name.  These storage arrays were EMC's main interest, but they also got 
(and killed) the computer parts.

> When I worked in the electronic field (basic stuff), the future was designer chips. That whole line of stuff never went anywhere and the rise of the commodity chips came to power. Now power itself is a major focus, since the true cost of energy is being realised

FWIW: The DG MV hardware with the ring capabilities was the basis for 
the book "The Soul of a New Machine" by Tracy Kidder.

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Chris Scheers, Applied Synergy, Inc.

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