[Info-vax] VMS internals design, was: Re: BASIC and AST routines

[Bill Gunshannon]

On 11/25/21 8:47 PM, Dave Froble wrote:
> On 11/25/2021 4:04 PM, Bill Gunshannon wrote:
>> On 11/25/21 2:20 PM, Arne Vajhøj wrote:
>>>
>>> Those running VMS today are mostly those without an easy way off
>>> VMS.
>>>
>>
>>
>> I would really like to know what people could be running on
>> VMS on an Itanic that would be so difficult to move to a
>> totally different system.  Any applications are almost
>> guaranteed to be written in an HLL.  Just what is it that
>> they are doing on VMS that can not be done on another
>> system?
>>
>> bill
>>
>>
> 
> I sort of don't like doing this, but, it is what it is ...
> 
> Your posts include working for the government and a university.  Perhaps 
> others, but that is what I recall.
> 
> I feel that perhaps you've never worked in an environment where being 
> profitable is the first consideration.  I may be wrong.

You would be wrong.  I have also worked for Martin Marietta (now
Lockheed Martin) and TRW (IND, not the car parts division).

> 
> Increasingly, companies depend on computer applications, note, not 
> computers, but applications, to run their businesses.  The cost is an 
> expense, not profitable, other than what such applications allow.
> 
> First, lets look at: "Any applications are almost guaranteed to be 
> written in an HLL."  I can point to at lease one application where that 
> is not true.  I've seen references to others also.  Just because you 
> don't have one doesn't mean others don't.

Considering that, like COBOL, no one is teaching any kind of assembler
they would have to be real legacy applications.

> 
> Many applications, maybe most, at least those still being used, running 
> on VMS would be costly to migrate/port to another environment.  I know 
> that that is true for Basic, and I suspect it to be true for most or all 
> languages.
> 
> Even if there might be some migration path other than total re-write, 
> there will be costs, there will be mistakes, and such.  This costs 
> money.  Money that takes away from profits, if not worse.

I never said it would be free.  But as someone else mentioned cost is
important but so is risk.

> 
> Just about anything can be done, with enough money and effort.  Where 
> would this money and effort come from?  For those whose business is 
> providing tha effort, perhaps they think the money should be available.  
> Those who would bear the cost might think otherwise.
> 
> Would VSI have customers now, if your conjecture had any merit?

But there is the rub.  VSI does have customers but based on the
comments I am still seeing here the numbers may be decreasing.
And people may be getting concerned about the time scale.

> 
> In my case, an extensive application written almost exclusively in 
> Basic+/BP2/VAX Basic/DEC Basic used to run multiple companies.  There is 
> no substitute that I'm aware of that could be used to run these 
> applications.  In all cases, there would be design work, programming 
> work, mistakes, business disruption, failure, and such.  Nothing 
> insignificant either, we're talking 7 or 8 digits.

Yes, but what does it do that your customers can't find another
product to do.  It may take major changes in the way they handle
the nuts and bolts of their business, but it happens every day.
The University I worked at had all in-house applications when I
got there. Running on Big Blue.  Moved the whole thing to VMS.
And then moved the whole thing to Banner.  No more VMS.  It can
be done and it is being done every day.  Don't get me wrong, I
don't think the model is a good idea, but then, I am not a CIO.
They do.

> 
> If it was so easy, why would not software competitors already have come 
> forth with replacement applications.  It's not like VMS users have been 
> treated well for many years by the OS vendor.  Where are those supposed 
> alternatives?
> 

VMS is a religion.  Just read what is said here.  But there have been
desertions.  The VMS constant no longer exists.  I expect there are
maybe 10% of that number left.  And it is a self-fulfilling prophecy.
Every defection decreases the long term existence of the product.

And, it still avoids my original question. What can you do on VMS
that can not be done on another system?  The effort and cost are
not a part of this equation.  Only the task to be done.  Cost
and effort decrease as risk increases.

bill