[Info-vax] 64-bit (was Re: New CEO of VMS Software)

[Arne Vajhøj]

On 1/11/2024 1:17 PM, Simon Clubley wrote:
> On 2024-01-11, Dave Froble <davef at tsoft-inc.com> wrote:
>> On 1/11/2024 8:56 AM, Simon Clubley wrote:
>>> On 2024-01-11, Dave Froble <davef at tsoft-inc.com> wrote:
>>>> On 1/10/2024 8:43 AM, Simon Clubley wrote:
>>>>> On 2024-01-09, Dave Froble <davef at tsoft-inc.com> wrote:
>>>>>> As far as I know, totally 64 bit apps can be implemented on VMS.  So, what's the
>>>>>> problem.  The fact that there is also that 32 bit capability hanging around
>>>>>> should not be a detriment, right?
>>>>>
>>>>> Try using RMS in totally 64-bit mode. Unless there's been further
>>>>> development since, not everything in RMS had a 64-bit address option.
>>>>
>>>> My understanding, which could be totally wrong, is that the major concept of "64
>>>> bit" is about addresses.
>>>
>>> And that is exactly what I am talking about. Not everything in RMS had
>>> a 64-bit addressing API the last time I checked.

That is correct. Practically only data related fields in RAB64
supports 64 bit addresses.

>> Then I have to ask, "so what?"=
> 
> You claimed that "totally 64 bit apps can be implemented on VMS".
> I am showing you why that is not the case.

I guess that depends on what is meant by "totally 64 bit".

If it means that all addresses stored in process space whether
user code or VMS code are stored as 64 bit then it indeed seems
unlikely.

It it means that in user code all addresses are 64 bit, then that
should be doable.

>> If RMS doesn't fit your requirements, then don't use it.
> 
> Everyone uses RMS, even if it hidden from you by the language. The RMS
> references are still in the executable you create however.

In practice yes.

In theory one can use SYS$QIO(W) for all IO and bypass RMS. But
it is very cumbersome (especially if one cannot use RMS for stuff
like finding IFI).

Arne