[Info-vax] Hard links on VMS ODS5 disks

[terry-...@glaver.org]

On Monday, July 24, 2023 at 1:12:45 PM UTC-4, Simon Clubley wrote:
> We are talking about structural and design issues within VMS that is 
> making this porting process a lot more involved than it should be.

They need to be emulated or mapped to new platform functions
unless you want to just call the operating system VMS but have it
be substantially different "under the hood" . That may work for some
things where both sides of an interface are internal to the operating
system, but (for example) not having supervisor mode is going to
have repercussions for some user code as well as require a re-
working of DCL.

The "low-hanging fruit" has already been dealt with in the VAX ->
Alpha -> Itanic progression.

For things that have been replaced with C code, performance tuning
may be needed once things are complete and deemed functionally
correct. This can take the form of in-line x86 assembly code or the
replacement of an entire C source file with an optimized assembly
version.

I have a Very Large Program that I have been dragging around with
me, starting on 4.2BSD/VAX and currently on FreeBSD/x86-64. It
does a more-than-reasonable amount of rummaging around inside
supposedly-internal operating system structures. So I have some
idea of the issues involved.