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

[Simon Clubley]

On 2021-11-25, VAXman-  @SendSpamHere.ORG <VAXman- at SendSpamHere.ORG> wrote:
> In article <sno4v1$efp$1 at dont-email.me>, Simon Clubley <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
>>
>>Compared to later operating system designs the internal design
>>of VMS is a direct product of the 1970s mindset because it is
>>ugly, hard to alter, not modular, full of internal hacks such
>>as jumping internally all over the place and was designed when
>>it was getting close to the end of when assembly language was
>>considered to be both an acceptable system implementation language
>>and an application language.
>
> What's hard to alter?  Many people say an alternator is difficult to
> replace.  I did one two weeks ago.
>

Have you ever looked inside the Linux internals to see how clean
they are compared to VMS internals ?

A really good starting point would be the VFS layer for plugging in
new filesystems so you can see just how easy and clean it is to add
a new filesystem to Linux compared to adding one to VMS.

Here's an overview document to get you started:

https://www.kernel.org/doc/html/latest/filesystems/vfs.html

Now try doing something like that on VMS.

>>Another such example is playing out right now as we speak.
>>
>>The engineers at VSI are talented, experienced and generally skilled
>>overall. However, due to how VMS was designed, it has taken even these
>>skilled people over 7 years so far to port VMS to x86-64 and they will
>>not be finished until the middle of next year at the earliest.
>
> LOL.  I suppose you could do it in a week.  I bow to your greatness.
>

No, I could not Brian. Nowhere near as fast as the experienced people
working on it and they have been at it for 7 years now.

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.