[Info-vax] date comparison format from a program

[gérard Calliet]

Le 22/05/2019 à 00:40, Dave Froble a écrit :
> On 5/21/2019 3:22 PM, gérard Calliet wrote:
>> Le 21/05/2019 à 18:29, Hans Bachner a écrit :
>>> Dave Froble schrieb am 21.05.2019 um 16:43:
>>>> [...]
>>>>
>>>> Now, I may be wrong, same old territory for me, but, if I was designing
>>>> something that had to last for a long time, I'd design it with "black
>>>> boxes" that perform a task, but can be replaced (inside the box) with
>>>> newer stuff.  As long as the "box" did what it was suppose to do, so
>>>> what?  More viable, probably cheaper.
>>>>
>>>> [...]
>>>
>>> Well, this is exactly what an emulator like CHARON-VAX does.
>> Of course.
>>
>> But the actual non emulated "box" does'nt depend on anything else, which
>> cannot be the case for any emulation.
>>
>> It seems very difficult to freeze all a stack with in it: some intel
>> hardware and some x boards, some windows version, the emulator.
>>
>> A real VAX with VMS 5.5-h4 can work years with not any reboot. I'm not
>> sure it's the case with emulated solutions.
> 
> Sometimes I get curious.  What can you tell us about this frozen in time 
> system and application?
> 
The have chosen specific hardware, specific boards, specific 
connections, certified all. And not any change is possible from that 
time, everything has to be replaced by the same thing. They have a stock 
for every part.

They have done a disk system specific, all of the organization of the 
disk plus all the procedures, lot of certifications, and from that time 
not other operation other than back/image of the model.

Same thing for the applications.

One example: the only crash they had in decades had been analyzed, and 
it was generated by an error on a procedure whixh didn't purge a .log 
which generated a problem not seen by VMS, and a crash. We had years of 
negociations to be authorized to change the procedure and we didn't be 
aauthorized to pass the patch about the VMS problem. And yes, no more 
crash since the procedure was changed, and no philosophical problems 
involved by the necessity of changing the heart by a patch.