[Info-vax] VAX VMS going forward

[Arne Vajhøj]

On 7/28/2020 3:09 PM, Stephen Hoffman wrote:
> On 2020-07-28 15:42:44 +0000, John Reagan said:
>> On Monday, July 27, 2020 at 5:55:52 PM UTC-4, Stephen Hoffman wrote:
>>> Getting a flat address space and getting rid of the mumble() and 
>>> mumble64() and 64-bit objects is no small development project, and 
>>> that's past the remediations for the forever-32-bit-app dependencies 
>>> that lurk.
>>
>> The address space is flat.  The CPU ensures that.  There are no 
>> segment registers on Alpha, Itanium, and x86 (in its 64-bit hardware 
>> mode).
> 
> The CPU is certainly capable of this, yes. I've never stated that the 
> Alpha and Itanium processors were not 64-bit. They are.
> 
> But until we've expunged all discussions of P0, P1, and P2, OpenVMS has 
> segmented addressing.

Obviously that depends on how you define segmented memory.

But using Wikipedia definition:

https://en.wikipedia.org/wiki/Memory_segmentation

<quote>
In a system using segmentation, computer memory addresses consist of a 
segment id and an offset within the segment. A hardware memory 
management unit (MMU) is responsible for translating the segment and 
offset into a physical address, and for performing checks to make sure 
the translation can be done and that the reference to that segment and 
offset is permitted.
</quote>

then no.

Arne