Thanks to everyone for the lengthy explanations, which are very helpful.
My conclusion is that I might as well stick to CDs for now,
leaving the CD drive in the present -- soon to be stand-by -- box.
I have a stock of 16 new CD-R's & a similar number of CD-RW's,
which seem to go on being rewritten, tho' slower than the CD-R's
(CDs are still popular: my local store has large numbers in stock).
I use them for long-term back-ups & for all-time archives,
as well as using USB sticks, so it's only after c 9 mth
(yes, I make daily USB back-ups & off-site on another machine every week).
I don't like the idea of keeping all my precious copies on 1 medium,
in case the Earth's poles reverse or some other magnetic catastrophe
causes all the HDDs, SSDs & USB sticks to be wiped out (smile).
It wb easy to copy the archive from a USB to the stand-by machine,
then write it to CDs there, given the long intervals between.
The CAD saved will go towards a more costly, but more cutting-edge mobo.
SUPPORT ___________//___, Philip Webb
ELECTRIC /]     | Cities Centre, University of Toronto
TRANSIT `-O----------O---' purslowatchassdotutorontodotca