[Info-vax] Kittson question

[johnwallace4 at yahoo.co.uk]

On Thursday, 1 January 2015 12:19:22 UTC, Simon Clubley  wrote:
> On 2014-12-31, JF Mezei <jfmezei.spamnot at vaxination.ca> wrote:
> >
> > But then, even though you may have a Unibus to PCI adaptor card, you
> > would then need to spend money upgrading the emulator itself to support
> > such a card.
> >
> > At which point, you need to wonder wether it costs less to update your
> > own application to connect to a modern PCI card on the new industry
> > standard system, or pay the company that makes the emulator to support
> > that PCI to UNIBUX adaptor so that you can use custom and very expensive
> > Unibus cards that have not been manufactured in ages and no replacement
> > available.
> >
> > If the industry has developped modern cards that are PCIe that do what
> > your decades old Unibus card does, then it seems you are much better off
> > getting a commodity card that plugs into PCIe and then hiring Mr VAXman
> > to do the driver.
> >
> 
> Unless they have some very VMS specific requirement (or lots of VMS
> specific code), the more likely answer, once they consider (a) modifying
> the software source code to be acceptable and (b) switching to a modern
> card is also acceptable, is to move the actual hardware interfacing/control
> to a modern box running a dedicated RTOS.
> 
> I suspect that in many cases, VMS was chosen because it was the most
> viable hardware interfacing/control option available at the time.
> However, in the embedded world, time has moved on dramatically since
> those days.
> 
> Simon.
> 
> -- 
> Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
> Microsoft: Bringing you 1980s technology to a 21st century world

Moving to a modern application on a modern OS on a modern box is a
"start again from scratch" tactic. Sometimes it's the best answer.

Sometimes that's not financially or technically sensible.

Preserving the existing investment in project software and
(project-specific) hardware, by moving to emulated software connected
to the existing IO, isn't for everyone, but there may be cases where
it's an entirely sensible option.