> > 2. Why does DCV exist at all? Can't I simply recast these in terms of
> > the PRM functions? A quick search with spotlight demonstrates that
> > nothing seems to use them.
>
> Don't know the real answer to this one (goes back too far, Malcolm may
> remember), but I've always assumed DCV predates PRM (note that it only
Just. They were developed in parallel. Steven Beard at ROE identified
the need for generic code, and having conversion functions were a
natural consequence. Meanwhile in Durham, Rodney was creating PRIMDAT.
PRIMDAT went much further than DCV, and DCV was soon dropped.
Some early KAPPA routines used DCV, but were soon converted to call
PRIMDAT.
> does the difficult unsigned conversions), so we've been moving from DCV to
> PRM for a couple of decades now (bit like the non-NDF KAPPA tasks saga)...
Well it would have got done a lot sooner had I been given a mandate and
allocated time to finish off the last 15-20 tasks. It never made it to
the SSGs wish lists. Like many of these jobs, they're dull and aren't
going to get supported over some swanky new functionality. It's not
alone. Look at all the cruft and duplication that was highlighted in
the move to CVS. There's still quite a bit of rationalising we could
achieve if we had the will and resources.
> As for replacing it directly with PRM calls, I've just looked at the code,
Yes let's remove invocations from our code and replace with PRIMDAT.
> it uses a brutal STOP when there's an overflow (so doesn't belong in an
> ADAM task, period). Maybe time for this lot to just die, unless anyone
> knows of a legitimate use for that nastiness (realtime?).
We don't know if DCV is used in legacy code, especially at its place of
origin. I think it may be in Asterix too. Is it much work to leave DCV
in GENERIC?
There's a three-exclamation whip for using STOP in any Starlink code in
SGP/16.
Malcolm
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